Aug 31, 2012: Cooler Start To September

Thursday, August 30 Observations:

Morning temperatures were quite chilly with the trough over the region from Wednesday, dropping as low as 47 degrees in interior areas, with widespread 50s observed outside of NYC. Lows in NYC dropped into the low to mid 60s.

High temperatures were warmer than Wednesday as the high pressure on top of the region continued to slide southeast, with a more westerly flow developing resulting in a very warm air mass quickly making its way in. Temperatures reached the low to mid 80s across most of the area with upper 70s in a few spots.


Friday, August 31 Observations:

A brief yet intense surge of heat moved through the region on Friday into Saturday, bringing a quick 2-day round of 90 degree temperatures. Highs reached the upper 80s to low 90s across most of the area with mostly sunny skies, with cooler temperatures observed further east into eastern Long Island. The hottest temperature was 94 degrees in Newark.




Forecast Overview:

Following today's brief heat surge, cooler temperatures will return into the area for the weekend along with dry conditions persisting, with highs on Saturday in the mid 80s for most of the area, a bit warmer in the immediate NYC area and cooler further east, and dropping into the mid 70s to low 80s for Sunday and Monday with more cloud cover and the risk of a few isolated showers.

More widespread storms are expected for Tuesday and Wednesday, especially late into Tuesday, as Isaac's remnants drift into the region. Risk of severe weather, if any, is still uncertain, although the potential is there for heavy rain with the remnants. Temperatures are likely to remain in the upper half of the 70s with occasional low 80s. Drier conditions appear to return for the end of next week, although no significant change in temperatures appears to be on the way, at least not yet.

More information on the outlook for Isaac's remnants, as well as an update on Tropical Storm Leslie, will be posted on Saturday.

**No Update Posted 8/30/12**

No update was posted tonight. The next update will be posted on Friday, 8/31.

Aug 29, 2012: Chilly Temperatures Tonight

Forecast Highlights:

- Lows to drop into 50s, some 40s tonight
- Brief heat surge for Fri/Sat, 90s for highs expected
- Rain associated with Isaac's remnants likely early-mid next week

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Wednesday, August 29 Observations:

Behind a cold front on Tuesday, a noticeably cooler air mass moved into the region for Wednesday, with 850mb temperatures only near 10C. Mainly sunny skies were observed with a high pressure on top of the region, with highs slightly cooler than expected, in the mid to upper 70s inland and in Long Island, and the upper 70s to lower 80s in most of the immediate NYC area and southern CT.



Forecast Overview:

Tonight will bring the coolest temperatures to the area in a week, since the last significant trough brought widespread lows in the 50s and some 40s for interior areas. Clear skies are expected with light winds and 850mb temperatures near 10C, allowing for temperatures to drop into the mid 40s to low 50s inland (NW NJ, interior SE NY), low to mid 50s for most places north/west of NYC and in southern CT, as well as the cooler spots in eastern Long Island, upper 50s in the immediate NYC suburbs, and upper 50s to low 60s in NYC.

This cool down will only be short lasting, however, as the high pressure over the region will slide to the southeast, allowing for a more westerly flow to develop at the surface and aloft with a warm air mass currently near the Midwest surging east into the region. Temperatures will quickly warm up into the mid to upper 80s for most places on Thursday, a bit cooler further east, with widespread upper 80s to low 90s expected on Friday with 850mb temperatures approaching 20C.

This warmth surge will be short lasting as well, however, as a cold front slides into the region on Saturday and Sunday, removing the short lasting heat. Temperatures on Saturday are expected to cool back down into the mid to upper 80s with a few spots in the immediate NYC area reaching 90 degrees, with highs returning into the lower half of the 80s for Sunday. A dry weekend is expected, although Isaac's remnants will be over the Ohio Valley region, slowly moving east while weakening. There is still some uncertainty regarding exactly what happens with Isaac's remnants, although it's likely that at least some storms associated with Isaac drift into the region around early-mid next week. Stay tuned for more information on next week's outlook.

Aug 28, 2012: Brief Cool To Brief Heat

Forecast Highlights:

- Cooler temperatures return for tonight-Thurs morning
- Surge of heat briefly comes in on Fri, possibly Sat
- Uncertainty with Isaac's remnants for longer range

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Tuesday, August 28 Observations:

Scattered showers affected the area after midnight with a line of heavier showers and thunderstorms coming through early in the morning hours associated with a cold front moving through. Clearing skies were observed later in the day behind the cold front with highs reaching the low to mid 80s inland and the mid to upper 80s across the rest of the area. The highest temperature was 89 degrees in Newark.



Tonight - Wed Night: Briefly Chilly

A high pressure will move into the region from the NW, resulting in mainly clear cloud cover and a cooler air mass with 850mb temperatures down to at least 10C, which will allow for cooler temperatures tonight through early Thursday. Lows tonight will drop into the mid 50s to lower 60s for most places north/west of NYC, with low 50s inland and low-mid 60s in NYC. Mainly sunny skies are expected for Wednesday with highs in the upper 70s to low 80s.

The coolest temperatures are expected for Wednesday night, with a similar set up expected again. Temperatures will quickly drop overnight with clear skies, with widespread lows in the low to mid 50s expected away from NYC. The immediate north/west suburbs will see lows in the upper 50s, with low 60s expected in NYC. The coldest temperatures will be in the interior areas, where lows are expected to drop into the upper 40s, perhaps a bit lower.


Thursday - Beyond: Briefly Hot, Then Cooler

A brief surge of heat will move into the region late on Thursday into Friday, resulting in a quick and significant warm up. Highs on Thursday are expected to reach the mid to upper 80s across most of the area, a bit cooler in Long Island/S CT, with highs on Friday reaching the upper 80s to lower 90s from NYC and further north/west and the mid 80s to lower 90s in Long Island/S CT.

The cold front now appears to move through faster than originally expected, which will likely push the heat south for Saturday and into the early week while delaying Isaac's remnants a bit. Cloud cover may increase towards Sunday and/or early next week as Isaac's remnants likely move into the region, although the exact timing and location remain uncertain. Stay tuned for more information regarding Isaac's remnants and how they affect the region.

Aug 27, 2012: Cool Midweek, Hot Weekend

Forecast Highlights:

- Cool temps for Weds and Weds night; lows in upper 40s-upper 50s away from NYC

- Heat briefly returns for Fri+Sat, 90+ degrees expected near NYC

- Watching Isaac's remnants for longer range

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Monday, August 27 Observations:

The area of showers and thunderstorms in the Mid Atlantic during the previous days drifted into the area during the morning, bringing an unexpected round of heavy thunderstorms producing heavy rain and localized flash flooding near NYC during the morning hours. Scattered storms were observed north/west of NYC in the afternoon as a cold front approached, moving through late overnight. High temperatures reached the low to mid 80s across the entire area.

Forecast Overview:

The latest radar, posted to the left, shows widespread storms to the north and west of the area. While most of the storms tonight are likely to stay north of NYC, scattered storms, locally heavy, are still expected late tonight into the first half of Wednesday. Storms may persist a bit longer into the afternoon hours for eastern areas with clearing skies from west to east. Highs will reach the upper 70s to mid 80s across the area.

Weds/Night: A trough will briefly move into the region, resulting in a brief yet significant cool down. Mainly clear sky conditions are expected with a high pressure moving through the region, with lows on Tuesday night in the mid 50s to lower 60s for most places away from NYC, a bit cooler inland (NW NJ/interior SE NY). Highs on Wednesday will reach the upper 70s to low 80s across the area, with overnight lows dropping into the low to mid 50s for most places away from NYC, with upper 50s closer to NYC and upper 40s inland.

Thurs-Sat: With the high pressure shifting south of the area, a west flow in the surface and aloft will develop with a surge of warmth moving in from the west. Mainly sunny skies will continue with highs reaching the mid to upper 80s on Thursday and the mid 80s to low 90s on Friday and Saturday. The most widespread low 90s are expected in the immediate NYC area.

Beyond Sat: The outlook after Saturday depends on what happens with Isaac's remnants; the GFS still brings the remnants into the region with some showers for Sunday and heavy rain on Monday with the heaviest rain north of the area. The CMC is faster and weaker with the remnants, taking them over the area, while the ECM suppresses the remnants well to the south. There is still uncertainty regarding this time frame, although the potential is there for some rain on Sunday and/or Monday.


Tropical Storm Isaac: 1 Day Left Before Landfall

As noted earlier this afternoon, Isaac has been a storm that continuously defied its forecasts. Environmental conditions in the Gulf of Mexico appeared supportive for potentially rapid intensification, but other factors ended up limiting any strengthening, as Isaac continued to deal with some dry air, moderate shear as the lowest shear was still not on top of Isaac, and an increasingly large storm size, which especially prevented Isaac from rapidly intensifying. Although Isaac is still a tropical storm with 70 mph winds, its minimum pressure is 979 mb, much lower than the average minimum pressure for a tropical storm; although the minimum pressure continued to drop and is still dropping, instead of having stronger winds in a smaller radius, the winds are distributed across a larger radius, which results in weaker maximum wind speeds but a larger storm size. Isaac is a very large tropical storm, with tropical storm force winds extending 205 miles outwards from the center. For the last two days, although I expected a category 3 hurricane, I mentioned that the possibility was there that Isaac would not rapidly intensify, and this now seems to be the case; with the factors above considered, as well as the fact that Isaac has less than a day over water, my intensity forecasts from the last two days will end up busting on the high side, as Isaac never rapidly intensified as expected.

Just because Isaac's wind speeds have not gone up much, however, it is no reason at all to take Isaac lightly. With the very large storm size, a significant storm surge is expected near the landfall region, and Isaac will also be very slow moving once making landfall, which will result in a widespread flooding potential with above 10 inches of rain expected. A similar scenario happened with Ike of 2008; the hurricane was expected to rapidly intensify in the Gulf of Mexico, but although its pressure rapidly dropped, its wind speed barely changed, and instead Ike significantly increased in its size, ending up as a very large hurricane. Although it made landfall with category 2-equivalent wind speeds, its storm surge and minimum pressures were about the equivalent of a category 4 hurricane, which resulted in more damage than what would be expected with a category 2 hurricane. While Isaac is not as strong or as large as Ike was, Isaac has some similarities to Ike; my current forecast for Isaac calls for slow yet gradual intensification until landfall as a category 1 hurricane, but with greater impacts than what would be expected from a category 1 hurricane.

Aug 27, 2012 Noon Update

Isaac - Unlike the expectation from yesterday, Isaac has failed to significantly organize itself, and instead has maintained its intensity throughout the day. Isaac continues to face the same difficulties it has dealt with yesterday, such as dry air and the large storm size also working against rapid intensification. Additionally, Isaac is also in an area of lower tropical cyclone heat potential in the Gulf of Mexico. While some strengthening to at least a category 1 hurricane is expected, the rapid intensification that once appeared possible is no longer expected. My updated outlook for Isaac tonight will significantly revise the forecast intensity downward, as well as including a more detailed explanation on what is going wrong with Isaac compared to the original forecast.

NYC Area storms - A narrow band of strong storms containing heavy rain and localized flash flooding is drifting NNE through NYC and the immediate NYC area. This band is capable of producing rainfall amounts up to at least 1/2 to 1 inch, locally higher. More storms are expected tonight with the cold front.

**Blog Statement**

*** Important Blog Statement ***

Starting 8/27/2012 through May 2013, the blog will feature less frequent updates. Forecast updates will be posted during most days of the week, and the additional pages (5-Day Forecast, Weather Alerts, ect.) will continue to be updated, but a few days during most weeks will have brief updates or no updates at all. While my mission remains to keep you updated on the latest in weather trends, this time period used to enhance the future of this blog will ultimately allow for better and more in-depth analysis of the weather. Stay tuned to updates as they come in.

Aug 26, 2012: Summer Not Over Yet

Forecast Highlights:

- Scattered storms expected Monday, Tuesday
- Cool temps briefly return for Wednesday night
- Next weekend: Summer's heat not over just yet
- TROPICS: Isaac headed towards New Orleans

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Notice: As of 8/26/12, the Tropics page is being discontinued. Discussions on tropical cyclones that threaten to affect the US directly will be posted in this page.

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Sunday, August 26 Observations:

An area of showers and severe thunderstorms continued to drift north through the Mid Atlantic, while generally dry conditions continued further north. More sunshine was observed than expected, with highs reaching the lower to mid 80s from NYC and further north/west and the upper 70s to low 80s in Long Island/S CT, verifying Sunday's temperature forecast.




Tonight - Wednesday: Storms, Then Cooler

Although today had more sunshine than expected, more widespread clouds are expected for Monday and early Tuesday as a cold front moves through the region. Partly to mostly cloudy skies are expected for Monday with scattered thunderstorms developing north and west of NYC, mainly in the late afternoon and evening hours. High temperatures are expected to reach the lower to mid 80s from NYC and further north/west and the upper 70s to lower 80s in Long Island/S CT. More widespread thunderstorms are expected during the overnight hours into early Tuesday as the cold front approaches, with a decreasing risk of storms by Tuesday afternoon with the front moving east and clearing skies later in the day. Temperatures are expected to be slightly warmer, in the lower to mid 80s across the area, although a few eastern areas may fail to reach 80 degrees.

A trough will then move into the region, resulting in cooler temperatures for Wednesday and Thursday. Mainly sunny skies are expected for Wednesday with highs in the upper 70s to lower 80s across most of the area. With clear skies, a high pressure overhead and 850mb temps near 10C, colder temperatures are expected overnight, dropping into the low to mid 50s for most places away from NYC, with upper 50s closer to the suburbs and low to possibly mid 60s in the city. Interior areas are expected to see lows in the upper 40s to lower 50s.


Thursday - Next Weekend: One More Surge of Heat

The cool down won't be long lasting, however, as ridging rebuilds into the region with a WSW/W wind developing as the high pressure shifts south of the area, allowing for a brief surge of heat. The heat won't be long lasting as well, however, as the flow remains generally progressive as well as Isaac's remnants likely disrupting the heat surge by the weekend. Highs on Thursday are expected to reach the upper 70s to mid 80s across the area with the warmest temperatures in the immediate NYC area along with mostly sunny skies; overnight lows will not be as cool as Wednesday night, likely dropping into the mid 50s to low 60s away from NYC.

The peak of the heat is expected for Friday and Saturday as the warmest air mass moves through, with 850mb temperatures approaching or reaching 20C, the first time this has happened since 7/26. With such conditions, temperatures are expected to reach the 90s in the immediate NYC area and perhaps in other parts of the area as well. Exactly how hot temperatures end up is still somewhat uncertain, with the heat surge also depending on Isaac's remnants and what they do once inland, although at this time low to perhaps mid 90s at most appears reasonable for a maximum temperature call, with upper 80s to low 90s more likely at this time. Afterwards, uncertainty increases as the forecast depends on what Isaac's remnants will end up doing, although the possibility is there that the remnants may end up moving through the area with a faster speed around the late weekend into the early week. Stay tuned for more information on the heat surge and what may happen with Isaac's remnants.


Tropical Storm Isaac: Entering Gulf of Mexico

Following yesterday's update, as Isaac gradually moved further away from Cuba's coast and into the Gulf of Mexico, it has attempted to reorganize itself and intensify. While it has noticeably improved in appearance today, Isaac once again faces a similar issue it had in the Caribbean as it lacks a solid inner core and its center is not aligned. Additionally, Isaac is also being affected by some dry air and about 10 knots of S/SW shear. The current lack of intensification may mean a slightly delayed period of intensification, although Isaac is still expected to strengthen in the Gulf of Mexico to hurricane intensity while approaching New Orleans.

Isaac's Track: Isaac continued to move in a WNW motion throughout the day while maintaining a moderately fast forward speed along with ridging still rebuilding to its north. Isaac will continue moving to the WNW/NW over the next 2 days through the eastern and north central Gulf of Mexico. There is still uncertainty regarding Isaac's track near landfall, however, as some models have Isaac turning north while ending up east of New Orleans as a result of a weakness in the ridge, while other models show the weakness having less of an influence on Isaac, with the storm instead sticking on a NW track until making landfall in south central Louisiana. There is no certain call yet regarding the exact landfall location, although at this time I am slightly shifting my forecast track to the west, taking it closer to New Orleans, although the high confidence landfall zone is from at least the AL/MS border to south central/SW Louisiana, and the exact landfall location may still shift a bit west/east.


Isaac's Intensity: The intensity remains the complicated aspect of Isaac's forecast, as intensification today has been slower than expected with Isaac still struggling to recover and form an inner core following land interaction 1-2 days ago. Isaac is still influenced by 10 knots of wind shear, which despite not completely inhibiting development, is not ideal for Isaac to rapidly intensify in the short term. Additionally, Isaac still does not have a solid inner core, an issue which it has had throughout its lifetime. Some positives signs for Isaac, however, include Isaac sustaining strong bursts of convection near its center, and as of the National Hurricane Center's 8 PM update, some strengthening has taken place with sustained winds up to 65 mph and minimum pressure down to 991 mb.

Given Isaac's current difficulties, rapid intensification is not expected for the next 12 to perhaps 24 hours. Recent observations, however, show that Isaac is slowly attempting to develop a core. For the short range, this is not likely to be a fast process although intensification is still expected to take place, especially with the sustained convection near Isaac's center, and gradual intensification is expected through Monday, when Isaac is likely to develop into a category 1 hurricane. Afterwards, intensification depends on when Isaac can develop a core and how much it will be able to intensify. Should Isaac be able to form a solid inner core within the next 24 hours with a favorable environment for intensification along with lower shear, rapid intensification may very well be possible to strong category 2 or category 3 intensity. The possibility is still there, however, that Isaac may fail to rapidly intensify in the Gulf of Mexico, and ends up weaker at landfall, perhaps a weak category 2 hurricane. For now, I slightly reduced the maximum intensity forecast to a low end category 3 hurricane, while delaying the intensification trend, although the intensity forecast is still subject to change. It is possible I may need to readjust the forecast intensity a bit higher should Isaac organize itself and rapidly intensify later on Monday, or lower the intensity to a category 2 hurricane should Isaac continue to take more time to intensify. A brief update will be posted on Monday afternoon regarding Isaac and any changes to the intensity forecast.

Regardless of the exact landfall location or the intensity, Isaac has the potential to be a damaging hurricane where it makes landfall, and the entire Gulf coast from western Louisiana to at least Palm City, FL, needs to keep a close eye on Isaac with a hurricane landfall likely.

Aug 25, 2012: Isolated Storms Through Tuesday

Forecast Highlights:

- Isolated storms continue Sun, scattered storms Mon-Tues
- Briefly cooler temperatures for Weds-Thu; 50s for lows
- Gradual warm up for late next week

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Saturday, August 25 Observations:

Following Friday's warm temperatures, cooler temperatures were observed on Saturday with more cloud cover and isolated storms over northern NJ during the mid-late afternoon hours. Temperatures ended up in the lower to mid 80s in the immediate NYC area and the upper 70s to lower 80s in Long Island/S CT. The estimated temperature outlines were not filled in for western NJ due to missing data from the three NWS observing stations in that region. Remarkably, Central Park had the warmest high temperature in the area, tied with Teterboro; this is the first time this has happened this summer.


Tonight - Tuesday: Clouds, Scattered Storms

Partly to mostly cloudy skies will continue over the next few days as clouds and storms drift north from the southern Mid Atlantic. Most storms will stay west and southwest of the area, towards Pennsylvania, although mostly cloudy skies and isolated storms are still expected for Sunday with highs in the lower to mid 80s from NYC and further north/west and the upper 70s to lower 80s in Long Island/S CT. A cold front will then approach the region on Monday, moving through the area on Tuesday. Mostly cloudy skies will continue on Monday and at least parts of Tuesday with scattered storms expected especially for Monday night and Tuesday. High temperatures on Monday will be similar to those of Sunday, if not slightly cooler, with slightly warmer temperatures for Tuesday.


Wednesday - Next Weekend: Cool, Warmer, Then Rain Possible

A trough will briefly move into the region for Wednesday and Thursday, resulting in colder temperatures as a high pressure moves in with 850mb temperatures dropping to near 10C. Wednesday is expected to have highs in the upper 70s to lower 80s across most of the area, with slightly warmer temperatures for Thursday, although overnight lows on Wednesday are expected to be quite cool; with mostly clear skies and a cool air mass, low temperatures are expected to drop into the 50s away from NYC, with low 50s inland towards NW NJ/SE NY. It is not out of the question that a few interior areas may drop below 50 degrees, although for now I am sticking with low 50s in the 5-Day Forecast.

Temperatures will then gradually warm up for the late week as warmer 850mb temperatures move into the region, with widespread low-mid 80s for highs returning on Friday, possibly a bit warmer in the immediate NYC area. The question then becomes what happens with Isaac's remnants, as there are two main possibilities at this time; one is where Isaac slows down after landfall in the Gulf of Mexico and is pushed east towards the Southeast coast and then offshore, the other is where Isaac continues to drift north into the central US, with its remnants then moving further east/northeast into the Northeast and/or Mid Atlantic, possibly including the NYC area. Until the exact scenario for Isaac once it moves inland becomes clearer, confidence remains lower for next weekend's outlook, although the possibility is there for storms to affect parts of the region, possibly including the area, perhaps associated with Isaac's remnants. Stay tuned for more information on next weekend's outlook.


Tropical Storm Isaac: Approaching Florida
**Updated at 10 PM to add new information and map

Following Isaac's sudden late minute intensification burst last night, Isaac made landfall in the western tip of Haiti, which disrupted Isaac's developing inner core and caused the storm to weaken from a 70 mph tropical storm to a 60 mph tropical storm with a minimum pressure of 1000 mb this afternoon. Since then, however, Isaac's minimum pressure has slightly dropped to 997 mb as Isaac managed to avoid spending a prolonged period of time over central Cuba.

Isaac's Track: Isaac is currently just north of the coast of eastern to central Cuba, and is moving NW. A general NW motion will continue for the next 2 days as weak ridging rebuilds north of Isaac with the tropical storm expected to move through the Florida keys late on Sunday through early Monday. This path will then take Isaac into the Gulf of Mexico, where it will continue to move WNW/NW before gradually turning more to the north later in the period as it approaches the Gulf coast. The model guidance differs regarding where landfall takes place, with the GFS showing landfall around the New Orleans region and the ECMWF showing landfall southwest of Tallahassee, FL; with Isaac's current fast speed and the continued WNW/NW steering currents, as well as recent trends with the model guidance to shift the landfall west, my adjusted forecast has Isaac making landfall in southeastern Mississippi, although the exact location is still subject to change and may end up somewhere between central Louisiana and southwest of Tallahassee, FL.


Isaac's Intensity: Land interaction has taken a toll on Isaac today as its appearance has become less organized during the day following Isaac's Hispaniola and Cuba landfalls. Isaac has slightly strengthened over the last few hours with the minimum pressure dropping 3 mb, although the latest observations as of 10 PM show that more convection is forming near Isaac's center northeast of Cuba. While the environmental conditions are not completely supportive for rapid intensification with the lowest wind shear still southeast of Isaac's center and Isaac still not showing a very organized appearance, additional intensification is likely to take place overnight into Sunday, and it is not out of the question that Isaac becomes a hurricane a bit earlier than currently forecast.

Once Isaac moves into the Gulf of Mexico, however, conditions will be much more favorable for intensification, and the possibility is there that Isaac may rapidly intensify in that region depending on how it emerges into the GOM. At this time, Isaac is expected to reach category 2 intensity, and should rapid intensification take place, category 3 hurricane could very well be within reach. Most of the models at this time strengthen Isaac into a strong category 1 hurricane; I am going more bullish than the model guidance with the intensity given the rapid intensification potential, but a little conservative compared to Isaac's full potential, stronger than a weak-moderate category 3 hurricane, although this will only be possible should Isaac end up with near ideal conditions for rapid intensification which is not a high confidence call at this time. The possibility is there that Isaac may fail to quickly intensify, in which case it would not intensify much more than strong Cat 1/weak Cat 2 intensity and my forecast intensity may have to be adjusted slightly downwards, although environmental conditions in the Gulf of Mexico appear supportive of more intensification, potentially rapid. The current intensity forecast is not final yet, however, and may still be revised downwards or upwards.

Regardless of exactly where Isaac makes landfall and with what intensity, Isaac has the potential to be a damaging hurricane where it makes landfall, and the entire Gulf coast from western Louisiana to Tallahassee, FL, including New Orleans, needs to keep a close eye on Isaac with a hurricane landfall likely.

Aug 24, 2012: Some Storms Monday/Tuesday

Forecast Highlights:

- Slight cool down this weekend; more clouds, a little rain possible
- Scattered storms for Monday/Tuesday
- Warmth potential by late next week

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Friday, August 24 Observations:

Partly cloudy skies were observed across the area as warm 850mb temperatures resulted in a slightly warmer day for most places. High temperatures reached the mid 80s inland, upper 80s in most of the immediate NYC area, and the low to mid 80s in Long Island and southern CT. The highest temperature was 91 degrees in Teterboro, NJ; the lowest high was 81 degrees in New London, CT.



Forecast Overview:

The weather pattern across the Northeast and the Mid Atlantic region remains generally inactive with the exception of scattered storms on Monday and Tuesday associated with a cold front. More clouds with isolated showers will drift north into parts of the region over the weekend for the south, resulting in cooler temperatures, with highs in the upper 70s to lower 80s across most of the area. A cold front will move through the region on Monday into early Tuesday with more widespread clouds and scattered thunderstorms, mostly staying west of the area on Monday while moving through overnight and into at least the first half of Tuesday. Temperatures for Monday are expected to be similar to those of Sunday, if not slightly warmer.

Tuesday's temperatures are expected to be around the upper 70s to mid 80s range with scattered storms expected, more likely during the first half of the day but possibly for the second half should it be a bit slower than currently expected. Temperatures will slightly cool down on Wednesday and Thursday with a trough moving through the region; highs are expected to reach the upper 70s to lower 80s on Wednesday and upper 70s to mid 80s on Thursday, with lows on Wednesday night dropping into the 50s away from NYC, perhaps the upper 40s inland, with 850mb temperatures cooling down to about 10C and a high pressure over the region with mostly clear skies.

By late next week, ridging is expected to rebuild into the region. There is some uncertainty regarding what happens with Isaac's remnants once they make landfall in the US, resulting in a variety of solutions for this time period, although at least a brief surge of heat is looking more likely at this time; should this surge of heat verify, it will not be long lasting, but it may signal 90+ degree heat making a return into parts of the region for the end of the meteorological summer.


Tropical Storm Isaac: Florida Targeted Twice

Since last night, Tropical Storm Isaac has finally managed to organize itself with convection sustaining itself closer to the center, allowing for Isaac to quickly intensify into a 65 mph tropical storm, stronger than expected last night. Isaac has also notably slowed down, and may very well become a weak hurricane prior to landfall in Haiti tonight. Isaac is still expected to weaken afterwards due to land interaction with Haiti and Cuba, likely taking it down to at least a moderate tropical storm. A general NNW path will continue for the short term, turning more to the NW as it passes through the northern parts of Cuba and through the Florida Strait.

Once reaching the Gulf of Mexico, Isaac appears to target Florida twice; first with a possible landfall near the Florida Keys, then with a second landfall near northwestern Florida. Isaac will turn more to the NW, but will not recurve straight up the East Coast, especially with some ridging to its north, a lack of a stronger trough to quickly pull it north, and steering currents still supporting a general NW track. The possibility is there that Isaac's remnants may slide off the SE US coast and continue offshore from there, but the storm will not take a classic East Coast tropical cyclone track with a trough over the Northeast region later on Tuesday and Wednesday. Regarding Isaac's intensity in the Gulf of Mexico, most models at this time show Isaac as a weak category 1 hurricane; although the extent of Isaac's intensification will depend on how it survives its track through Hispaniola and Cuba, the possibility is there for more rapid intensification into a hurricane, perhaps up to category 2 intensity, in the eastern Gulf of Mexico.

Based on latest trends with Isaac in the short term it is increasingly likely its passage over Cuba will be shortened, which may also favor more intensification in the Gulf of Mexico region. At this time, I am expecting landfall somewhere within or near the general region between south of Tallahassee and Pensacola, Florida. Afterwards, there is more uncertainty with its remnants depending on the exact timing and location of the landfall along with the timing of the Northeast cold front; there isn't high confidence yet regarding the remnants, although two main possibilities are for the remnants to drift north into the south/central US or to slowly drift ENE through the SE US and then offshore.

Aug 23, 2012: Mostly Dry, Seasonable

Forecast Highlights:

- Generally seasonable temperatures to continue
- Some showers possible for early week

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Thursday, August 23 Observations:

Temperatures slightly warmed up on Thursday as mostly sunny skies returned with a high pressure moving into the region. High temperatures were warmer than those of Wednesday, reaching the mid to upper 80s from NYC and further north/west and the upper 70s to mid 80s across Long Island and southern CT. The highest temperature was 88 degrees in Caldwell, NJ, with the coolest high 78 degrees in New London, CT.



Forecast Overview:

The forecast through mid next week remains unchanged; mostly sunny skies with highs in the low to mid 80s east of NYC and mid to upper 80s NYC and N/W are still expected for Friday. Partly cloudy skies are expected from Saturday through Monday along with the risk of isolated showers, with highs cooling down into the upper 70s to lower 80s across most of the area, perhaps a bit cooler further east in Long Island. A cold front will move through the region on Monday night and Tuesday, resulting in scattered showers and storms with highs on Tuesday slightly warmer, followed by a trough moving into the region on Wednesday with highs cooling back down a bit into the upper 70s to lower 80s for most of the area. The longer range becomes more uncertain due to significant differences regarding what Isaac's remnants will do once over the US, resulting in significantly lower confidence in the forecast at this time beyond the middle of next week.


Tropical Storm Isaac: Will Not Move Up The East Coast

Over the last few days, there has been speculation regarding the possibility that Tropical Storm Isaac moves up the East Coast, similarly to last year's Irene. As my expectations have been with the previous two updates and are still mostly unchanged other than increased confidence and minor track/intensity adjustments, Isaac will not move up the East Coast, instead heading into the eastern Gulf of Mexico region.

Isaac's Intensity: As expected from last night, Isaac continues to struggle with its organization and thus has failed to intensify much, with sustained winds at 45 mph and a minimum pressure at 1001 mb. Although Isaac's center is not far SE of Haiti, the majority of its convection remains displaced to the southwest of the center. Isaac has less than 24 hours left before it makes landfall in Haiti on Friday, and given its current issues, will not strengthen much prior to landfall; I am expecting Isaac to make landfall with sustained winds between 45-50 mph. Following landfall, Isaac is expected to stop strengthening and at least slightly weakening due to land interaction.

The intensity forecast becomes more complicated as even a slight change in the forecast track will have an impact on Isaac's intensity. At this time, Isaac is expected to move over Cuba near its northeastern coast; should Isaac remain entirely over Cuba before exiting to the NW, it will end up weaker, and will struggle to intensify again right after coming offshore. Should Isaac end up less over Cuba and more over water, however, it may not weaken as much, and would end up stronger going into the Gulf of Mexico. At this time, my forecast track keeps Isaac in the northeastern coast of Cuba as a 45 mph storm, although some minor changes are still possible. Isaac's intensity in the Gulf of Mexico is more uncertain, although intensification to hurricane intensity is expected should Isaac easily survive its passage through Hispaniola and Cuba.


Isaac's Track: After briefly moving WSW last night, Isaac turned to the WNW today, although it will still end up mostly south of Hispaniola before making landfall in the westernmost parts of Haiti. Isaac will then continue WNW towards Cuba; there is still some uncertainty regarding whether Isaac spends more time over Cuba or over water, which as previously mentioned will also determine its intensity. Isaac will continue to be steered to the WNW/NW, and while there is a weakness in the ridge to its north, Isaac will not turn north and move up the coast, especially with ridging slightly rebuilding to its north; there is no model support for such a solution, and such a track is not expected. Model solutions range from the NAM, which was the northeastern outlier today taking Isaac east of Florida, to the ECM, the western outlier taking Isaac into western Louisiana. Although the ECM did correctly start the trend of Isaac moving through the Gulf of Mexico as opposed to the eastern coast of Florida, it still appears to be a bit too far south/west, and at this time I am siding with a solution in between, a bit closer to the GFS, with landfall possible somewhere around far western Florida. The exact location of the landfall is still subject to change within that general region, however.


Isaac's Impact on the US: Although Isaac will not move up the East Coast, its remnants will affect parts of the central/eastern. There is still uncertainty with exactly where Isaac's remnants will end up tracking once Isaac tracks inland, although the potential is there that the remnants may affect at least parts of the Mid Atlantic and Northeast region. More information will be posted regarding Isaac's inland impact in the US once confidence increases regarding the location of Isaac's landfall.

Aug 22, 2012: Dry Conditions Through Monday

Forecast Highlights:

- Partly sunny, little rain through weekend
- Storms may be possible early-mid next week

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Wednesday, August 22 Observations:

Mostly dry conditions were observed across the area on Wednesday, although a heavy thunderstorm popped up over NE Essex county during the afternoon, resulting in localized flash flooding with above 2 inches of rain in that small area. Temperatures were generally similar to those of Tuesday with highs in the lower 80s for most of Long Island/S CT and the lowre to mid 80s from NYC and further north/west. The highest temperature observed was 89 degrees in Teterboro although as observed several times earlier in the month, its high is noticeably higher than surrounding stations between 82-84 degrees.


Forecast Overview: More Clouds/Few Showers For Weekend

Little changes in the set up are expected through Sunday and possibly Monday with a high pressure over the region, focusing north of the area, with mostly to partly cloudy skies expected. Highs will be slightly warmer for Thursday and Friday, reaching the lower to mid 80s from NYC and further north/west, exceeding 85 degrees in the immediate NYC area, with upper 70s to lower 80s in most of Long Island/S CT.

Showers and clouds will stall offshore in the late week, and could advance north into parts of the area especially further south/east later on Saturday into Monday. Highs are likely to end up in the mid 70s to lower 80s across the area with partly to perhaps mostly cloudy skies along with a risk of isolated showers, especially east of NYC. The next cold front will then approach the area on Monday and Tuesday with a risk of showers and thunderstorms with highs likely remaining similar to those of the weekend. Behind the front, there is more uncertainty depending on exactly what Isaac does, although temperatures may remain in the upper 70s to lower 80s range.


Tropical Storm Isaac: More Likely To Enter Gulf of Mexico


Until yesterday, Isaac had many similarities to last year's Irene; both were each season's 9th named storm starting with an "I", both formed in the same region, one day apart, and they were generally moving in the same direction. As yesterday's update mentioned and is still expected as of today, however, despite the similar beginning, both storms will not have the same ending. Irene went on to move up the East Coast and produce widespread flooding and damage, while Isaac is taking a route towards Florida and perhaps the northeastern Gulf of Mexico.

Isaac's Intensity: Isaac, as with other storms in this basin earlier this year, has failed to significantly intensify. Isaac continues to quickly move west, with its forward speed having varied between 18-22 mph today. Dry air is still having some impact on Isaac, and despite its large size, it remained disorganized without a well defined center throughout the day and held at 45 mph as of NHC's 11 PM update. Since then, stronger convection has been forming on top of Isaac, although it's not completely consolidated yet, with the latest satellite loop showing the convection pushing to the SSW. With Isaac approaching the mountains of Hispaniola, known for disrupting tropical cyclones, Isaac has a small window of opportunity to organize itself and intensify into a hurricane. With the limitations ahead of Isaac, I am expecting gradual intensification into a strong tropical storm prior to reaching Haiti, with a weak category 1 hurricane not out of the question should Isaac be able to organize itself tonight and intensify faster on Thursday.

There is uncertainty regarding whether Isaac moves over Hispaniola or stays to the south; the latest model guidance takes it over the island, although the trend has been slightly to the west, and especially if the latest satellite observations prove to be a SW wobble in Isaac's track, it may help Isaac to either stay near the southern edge of Hispaniola or barely miss the island to the south. Isaac is then expected to track over Cuba; both of these islands will likely disrupt Isaac to some extent, preventing Isaac from becoming a stronger hurricane in the Caribbean basin. Once it emerges from Cuba, latest trends point to Isaac staying west of Florida; should this be the case, which is increasingly likely as will be discussed below, additional intensification is expected in the eastern Gulf of Mexico, which is where Isaac will have a better chance of intensifying into a stronger hurricane. The exact track is still uncertain, although it is recommended that the entire Gulf of Mexico coast from Louisiana to Florida pay close attention to Isaac.


Isaac's Track: As discussed yesterday, there are already differences with Isaac and Irene which continued to grow today; Irene went over Puerto Rico and north of Hispaniola while becoming a strong Category 1 hurricane; Isaac, however, is staying south of Puerto Rico and will approach the southern coast of Hispaniola as a strong tropical storm or weak hurricane. Especially if the latest satellite trends are an indication of a SW wobble in Isaac's track, it may keep Isaac slightly south of the latest model consensus, which further decreases the probability of Isaac moving up the East Coast. A weakness in the ridge north of Isaac is expected as it approaches Cuba, with Isaac turning more to the NW, although especially with its continued west track, it is an increasing likelihood that Isaac enters the eastern Gulf of Mexico. A forecast track map will be posted with Thursday night's update; at this time, I would place the cone of uncertainty from eastern Florida to New Orleans, with the main track going into NW Florida.


Impact in the rest of the US: Once Isaac makes landfall in the US, which is likely, its remnants would make their way north, which could spread heavy rains associated with Isaac further inland. The location of where this happens is still uncertain, however, and depends on where Isaac makes landfall and the direction in which it will be moving. The possibility is there that Isaac's remnants may reach the region, although Isaac is not expected to be a tropical cyclone should it affect the region. Stay tuned for more information on Isaac's impact in the US.

Aug 22 Morning, 2012: Little Changes In Forecast

Forecast Highlights:

- Mainly dry, seasonable conditions through weekend
- TROPICS: Keeping an eye on Tropical Storm Isaac

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Tuesday, August 21 Observations

Mostly/partly sunny skies continued across the area on Tuesday with temperatures slightly warmer than those of Monday, reaching the upper 70s to lower 80s across the entire area. The coolest high was 78 degrees in New London, CT; the highest temperature was 83 degrees, tied between Teterboro, Newark (NJ) and LaGuardia (NY).



Wednesday - Early Week: Little Changes In Forecast

As with August 20's update, there is not much to mention in this morning's discussion other than the generally seasonable conditions lasting through the weekend and into early next week. Isolated showers may still be possible on Wednesday, otherwise a high pressure builds into the region through the weekend staying north of the area, slowly moving offshore by Monday. Through Thursday, partly/mostly sunny skies will continue with highs in the lower to mid 80s from NYC and further north/west, above 85 degrees in parts of the immediate NYC area, with upper 70s to lower 80s in most of Long Island/S CT.

The center of the high pressure is expected to stay north of the area, with more of a south wind expected by Friday through the weekend. Temperatures through Friday and Saturday, temperatures similar to those of the late week are expected to continue. A weak cutoff low may end up southeast of the area by Sunday and Monday, which would result in increased cloud cover especially further south/east along with slightly cooler temperatures. The next cold front is likely to affect the area with a risk of rain around early-mid next week, perhaps focusing around Tuesday.


Tropics: Watching Tropical Storm Isaac

With very little interesting weather in the Northeast region, attention turns to the Caribbean, where Tropical Storm Isaac formed today. There are several coincidences comparing Isaac to last year's Irene; both of them start with "I" as both are the 9th named storms of their hurricane seasons, they formed in the same region one day apart and both are generally headed in a similar direction in the northern Caribbean. Despite this very similar start, however, the storms are unlikely to have a similar ending. Irene had a more northerly component to its movement and crossed Puerto Rico, staying north of the Caribbean islands and east of the Bahamas while intensifying and recurving at the right angle for an East Coast hurricane. Isaac, however, has more of a westerly component to its movement, and is increasingly likely to track over Hispaniola, which if happens, may disrupt Isaac's intensification or cause weakening; Hispaniola's mountains have managed to disrupt tropical cyclones including recent examples of 2006's Ernesto and 2008's Gustav, despite expected intensification.

While Isaac is on track to target Florida, it is uncertain if it ends up on the west or east side of Florida; most model guidance takes it just east of Florida, although the ECM has been consistent with a Gulf of Mexico strong hurricane, and the GFS has fluctuated between just west and just east of Florida. The ECM at this time is likely the western outlier, although there is still not enough confidence at this time to know exactly whether Isaac will track west or east of Florida. At this time, I am siding with a track taking it just east of Florida; should it take this track, the possibility is there that some form of Isaac, either a tropical storm or remnants, especially should it move inland over the SE US first, may move through parts of or most of the East Coast, but this is not likely to happen in the form of a hurricane moving up the coast as Irene did. While Isaac is unlikely to have the same type of impact Irene had on the East Coast, it will be watched for the possibility that Isaac may have some impact, more likely indirect in the form of remnants, north of the SE US. At the same time, a western solution taking it west of Florida and into the Gulf of Mexico is also not out of the question, especially should the ridge to Isaac's north remain strong with Isaac continuing on a west/WNW path. Stay tuned for more information on Isaac with tonight's update.

Aug 20, 2012: Chilly, Then Slowly Warming Up

Forecast Highlights:

- Temperatures to slowly warm up this week, weekend
- Little, if any rain expected through early next week

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Monday, August 20 Observations:

Partly cloudy skies were observed across the area with scattered storms moving in from the west in the evening hours, affecting the western parts of the area. Temperatures were slightly warmer than the previous day (8/19) when the entire area was in the 70s, the first time this has happened since 7/20, almost a month earlier. Highs reached the upper 70s to lower 80s from NYC and further north/west and the mid to upper 70s in Long Island and southern CT.



This Week, Weekend: Temperatures Slowly Warming Up

Although some changes will take place with the pattern this week, including the trough lifting out of the region with rising 500mb heights, there is not much to say with tonight's update other than that conditions for the NYC area are generally expected to remain the same through early next week with little changes. Other than the possibility of isolated showers on Tuesday and Wednesday, dry conditions will persist. Highs on Tuesday and Wednesday will reach the upper 70s to lower 80s for most of the area, with lows in the mid 50s to lower 60s outside of NYC, dropping into the lower 50s in the higher elevations inland.

With a warmer air mass moving in along with a high pressure, less cloud cover is expected for the end of the week and into next weekend, although a cutoff low pressure may remain offshore, keeping the area under the influence of onshore winds with the warmest temperatures staying further inland. During this time period, highs will likely end up warmer west of NYC, in the lower to mid 80s with upper 80s for some days in the immediate NYC area, while locations east of NYC see temperatures in the upper 70s to lower 80s, with mid 80s possible during the warmer days. Overnight lows will gradually trend higher, with lows in the upper 50s to mid 60s expected outside of NYC by the late week.

Aug 19, 2012: Cooler Week Ahead

Forecast Highlights:

- Heat/humidity end; cooler temperatures continue this week
- Some showers/storms possible Monday and Weds
- Slight warm up next weekend

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Sunday, August 19 Observations:

The forecast for 8/19 was for mostly sunny skies, although instead mostly cloudy skies were observed, which resulted in colder than expected temperatures. Chilly morning temperatures were observed with widespread lows in the 50s, even dropping into the upper 40s for interior areas. Highs reached the lower to mid 70s inland and the mid to upper 70s in the immediate NYC area, southern CT and Long Island. This was the first time high temperatures were below 80 degrees in the entire area since 7/19, almost a month earlier.


Monday - Wednesday: Still Chilly, Some Rain Possible

There was initially some confusion regarding tomorrow's outlook, as the NAM and ECM models had a coastal low close to the area, producing widespread rain with highs only in the 60s, while the GFS and CMC kept the coastal low southeast of the area, with warmer temperatures reaching the 70s and peaking near 80 in a few areas. The NAM occasionally tends to exaggerate storm scenarios like this one, however, and the recent NAM and ECM runs backed away to a further offshore solution as well, with temperatures in the 70s across the area. Cloudy to mostly cloudy skies with isolated showers are expected further east, while places west of NYC will likely have occasional breaks in the cloud cover with isolated afternoon/evening storms. Brief updates may be posted tomorrow, if needed.

Drier conditions will return for Tuesday with partly sunny skies, highs in the mid 70s to low 80s, and the risk of isolated showers. By Wednesday, the NAM and ECM show another coastal low while the GFS has isolated showers and the CMC keeps the low to the southeast. Considering how the original outlook for tomorrow went, at this time I'm expecting additional isolated showers with highs also in the mid 70s to low 80s.


Thursday - Beyond: Slight Warm Up, But No Heat

Temperatures are expected to warm up in the late week and into next weekend as the trough lifts out of the eastern and central US with rising heights, and for the first time since early August, the gap between the western US ridge and the western Atlantic ridge closes over the region. Temperatures are expected to reach the lower to mid 80s for most of the area, reaching the upper 70s in coastal areas and perhaps the upper 80s in the immediate NYC area on the warmer days. The orientation of the high pressure isn't favorable for widespread heat, especially with S/SSW winds as opposed to WSW winds, although a warm air mass is still in place, which should keep temperatures similar to those of the late week through the weekend and into the early week. The next cold front at this time appears to be towards the middle of next week, although some changes are still possible given the time range.

Aug 15-18, 2012 Observations

Below are the area observations for August 15-18, 2012. Today's update (August 19) will be posted this evening.

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Wednesday, August 15 Observations:

August 15 was an active day for the area, with night/early morning storms staying north/NW of NYC and mostly north of the area, although strong storms formed over Long Island, which was already frequently hit with severe storms this year, with additional scattered and slow moving strong storms forming over Long Island throughout the morning and into the early afternoon. Flash flooding and strong winds were observed with the strong storms, including eastern parts of NYC and Nassau County. Additional strong storms developed in the afternoon, mostly focusing over NE NJ and NYC.

Temperatures were slightly warmer than 8/14 west of NYC and cooler east of NYC. Highs peaked in the lower to mid 80s from NYC and further north/west and the mid 70s to low 80s in Long Island/S CT. The highest temperature was 86 degrees spread out across NE NJ; the coolest high was 76 degrees tied in Bridgeport, New London (CT) and Montauk (NY).


Thursday, August 16 Observations:

Drier conditions returned to the area as a weak area of high pressure moved in with the low pressure moving up the coast, into Maine. Warmer temperatures were observed across the area, with mid 80s across most of the area with upper 80s in parts of the immediate NYC area. The highest temperature was 88 degrees in Newark; the coolest high was 82 degrees in Danbury, CT.




Friday, August 17 Observations:

A moderately strong cold front moved through the region associated with a strong trough dropping into the central US, resulting in widespread colder than average temperatures in that region. Cloud cover increased throughout the day with scattered storms moving through in the late afternoon and evening hours. The storms initially affected western NJ, dissipating near NE NJ as additional strong storms formed in NYC, western LI and southern CT. Overnight, widespread thunderstorms moved through, resulting in additional moderate to locally heavy rain and thunderstorms.

Temperatures were warmer than the previous days ahead of the cold front, with temperatures reaching the mid 80s inland, upper 80s to lower 90s in the immediate NYC area, and the mid 80s across most of Long Island/S CT. The highest temperature observed was 94 degrees in Teterboro, although it is several degrees higher than the surrounding stations; the coolest high was 81 degrees in Montauk, NY.


Saturday, August 18 Observations:

Thunderstorms persisted across the area throughout the overnight hours, lasting into the morning and early noon hours from NYC and further east, with clearing skies taking place in the second half of the day. Temperatures were cooler behind the cold front, with highs reaching the upper 70s inland, lower 80s in the immediate NYC area, and mid to upper 70s in Long Island/S CT. The highest temperature observed was 82 degrees in parts of NE NJ; the coolest high was 73 degrees in New London, CT.

Aug 17, 2012: Cooler Temperatures Next Week

Forecast Highlights:

- Storms continue tonight, first part of Saturday
- Cooler temperatures expected most of next week
- Warm up likely late next week/weekend

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Observations for 8/15 through 8/17 will be added on Saturday.


Weekend Outlook: Cooler Temperatures Expected

Occasional storms are expected across parts of the area tonight as storms move in from the southwest as shown to the left in the regional radar. Some storms will continue on Saturday morning and the early afternoon hours, especially from NYC and further east, although clearing in the cloud cover is expected later in the day in the western parts of the area, with highs peaking in the upper 70s to low 80s from NYC and further north/west and the upper 70s, possibly a bit cooler, in Long Island/S CT.

A cooler air mass will move in behind the trough, with one of the coolest nights of the summer expected. Clearing skies will take place overnight with lows dropping into the upper 40s to low 50s inland, mid 50s to low 60s for the north/west suburbs and Long Island/S CT, and the low to mid 60s in NYC. Mostly sunny skies are expected for Sunday with highs in the upper 70s to low 80s.


Next Week: Still A Little Cooler

The cool air mass will remain close to the Northeast, with temperatures not changing much through the first half of the week. There is some uncertainty regarding Monday's outlook as previous GFS runs and the ECM only have mostly cloudy skies with scattered showers, while the CMC and the recent 0z GFS show a stronger coastal low pressure with widespread rain and chilly temperatures. For now, I put scattered showers and highs in the upper 70s to low 80s in the forecast, although the forecast is still subject to some changes.

Partly cloudy skies are expected for Tuesday with more sunshine for Wednesday and Thursday, with highs returning into the low 80s for most of the area. By late next week and into perhaps the weekend, however, temperatures will slightly warm up as 850mb temperatures warm up a little with rising 500mb heights, with highs reaching the low to mid 80s for most of the area and upper 80s in parts of the immediate NYC area.

**No Update Posted 8/15 and 8/16, 2012**

No forecast discussion was posted tonight and on Thursday, 8/16. The next update will be posted on Friday, 8/17.

Aug 15, 2012 Storm Updates

Updates for today's storms can be found in the NYC Area Weather twitter page:




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2:50 PM: More Widespread Storms Forming

Briefly summarizing this morning's activity, following overnight heavy storms north of NYC, scattered strong storms developed over Long Island, which has been frequently hit with strong/severe storms this year, with storms lasting through the morning and early afternoon hours. Some of these storms were severe, especially in western Long Island and parts of Queens/Brooklyn where a severe storm stalled, producing heavy rain with flash flooding, strong winds, and hail. Radar estimates show rain totals may have locally exceeded 2 inches.

The latest radar shows scattered storms developing over the area, some of them strong, especially over Staten Island. Scattered storms, some of them strong/severe with heavy rain, strong wind gusts and small hail, will continue to affect the area through the evening hours, with clearing skies later in the overnight hours. Stay tuned for more updates this afternoon in the NYC Area Weather twitter page.

Aug 14, 2012: Cooling Down Slightly Next Weekend

Forecast Highlights:

- Scattered storms to continue today, tomorrow
- Additional storms expected Fri/Sat with cold front
- Slight cool down for Sun-early week; sub-80 highs possible
- Warmer temperatures for late next week possible

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5-Day Forecast Changes

The poll has been closed; the clickable map (Google Maps) with text for each forecast area is now the new 5-Day Forecast format. A text-only version of the forecast is available in case there are issues with viewing the map.

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Observations for August 12 and 13 can be found in the bottom of the post.

Tuesday, August 14 Observations:

The day started out with increasing cloud cover as an area of strong thunderstorms in eastern Pennsylvania slowly moved east, affecting the western parts of the area with locally heavy rain in the late morning before the storms weakened as they reached the immediate NYC area. Following the dissipation of the late morning storms, the area stayed mostly dry through the rest of the day while scattered thunderstorms formed in other parts of the region. Temperatures were cooler than the previous days due to the cloud cover and storms, peaking in the upper 70s inland and the lower to mid 80s across the rest of the area.


Tonight - Tomorrow: Storms to continue

Following the morning storms in the western parts of the area, mainly cloudy skies are still covering the area as of the late afternoon hours, with most of the area still dry while scattered storms are forming to the west and south. Most of the storm activity this evening and tonight will remain to the west and north of the area, although isolated storms are still expected tonight especially north/west of NYC. Another round of scattered storms is expected on Wednesday afternoon and evening with highs reaching the upper 70s to mid 80s across the area.


Thursday - Beyond: More Storms, Then Cooler

Dry conditions will briefly return for Thursday with mostly sunny skies and highs reaching the lower to mid 80s across the area. The next cold front will enter the region on Friday as a strong trough drops into the central US, bringing widespread cool temperatures, while slowing down as it approaches the coast. Partly cloudy skies are expected on Friday with temperatures warmer, peaking in the mid to upper 80s for most of the area with lower 90s in parts of the immediate NYC area. Cloud cover will increase by the afternoon/evening hours, with scattered storms expected overnight and during Saturday as the cold front comes through. Cooler temperatures are expected on Saturday, although there is still some uncertainty regarding exactly how cool; for now, I put highs in the upper 70s to low 80s in the forecast, although should the cloudier/wetter scenario verify for Saturday, temperatures would end up a few degrees cooler than currently expected.

A cooler air mass will move into the region behind the cold front for Sunday into the first half of next week, although the trough will remain centered near southern Canada and the north central US, failing to move directly over the region with the western Atlantic ridging holding steady in place, keeping the area near the eastern edge of the cool air mass. Cool temperatures are expected for Sunday and Monday, with morning lows in the mid 50s to low 60s for most of the area, slightly warmer in NYC, and daytime highs peaking in the upper 70s to low 80s. A gradual moderation in temperatures is likely throughout the rest of next week back well into the 80s.



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PREVIOUS DAILY OBSERVATIONS:


Sunday, August 12 Observations:

As a low pressure in the Great Lakes drifted out of the region, mostly to partly sunny skies returned to the area with temperatures reaching the lower to mid 80s inland, mid to upper 80s in the immediate NYC area, and the low to mid 80s in Long Island and southern CT. Temperatures inland were slightly cooler than the previous day, while the rest of the area had similar temperatures. The coolest high was 81 degrees, tied with New London, CT and Andover, NJ; the highest temperature was 88 degrees, tied with Teterboro and Newark, NJ, and LaGuardia Airport.


Monday, August 13 Observations:

Mostly sunny skies were observed again across the area with temperatures similar to those of Sunday, reaching the lower ot mid 80s inland, mid to upper 80s in the immediate NYC area, and the mid 80s in most of Long Island/S CT. The coolest high observed was 80 degrees in New London, CT; the highest temperature was 88 degrees in Newark, NJ.

Aug 12, 2012: Some Storms This Week

Forecast Highlights:

- Seasonable start to week ahead
- Isolated storms expected Tues/Weds, late week
- Moderate cool down possible next weekend

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REMINDER: The poll for changes in the 5-Day Forecast format remains open until Wednesday. More
information can be found here.


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Friday, August 10 Observations:

As a low pressure developed near southeast Michigan, widespread cloud cover was present across the region with areas of thunderstorms. The highlight of the day was a line of strong to severe storms that moved through in the late morning to early afternoon hours, producing widespread 1-2+ inches of rain for almost the entire area except for parts of NE NJ and NW NYC, which had very little rain. The severe storms, originally expected to be in the Mid Atlantic, unexpectedly affected Long Island and SE New England instead, with an EF-0 tornado confirmed in Suffolk county.

Temperatures on Friday were a bit cooler than Thursday, reaching the upper 70s inland and the lower to mid 80s across the rest of the area. The coolest high temperature was 75 degrees tied with Montgomery, NY and Sussex, NJ. The highest temperature was 87 degrees near Teterboro, although this temperature is interestingly several degrees higher than surrounding stations, even Newark which is typically the hot spot of the area.


Saturday, August 11 Observations:

Following Friday afternoon's storms, the overnight hours were generally dry across the region, although scattered storms were observed during the day, to the north/NE of NYC during the late morning and to the southwest of NYC during the evening. Temperatures were warmer than Friday, reaching the mid to upper 80s from NYC and further north/west and the lower to mid 80s in Long Island/S CT. The highest temperature was 89 degrees in Teterboro and Newark, with the coolest high 80 degrees in New London, CT.


Sunday - Wednesday: Seasonable, Some Storms

Following the departure of the Great Lakes low pressure from the region, mostly to partly sunny skies returned with temperatures reaching the mid to upper 80s from NYC and further north/west and the lower to mid 80s in Long Island/S CT. Similar temperatures are expected to continue for Monday, slightly warmer on Tuesday with more widespread upper 80s from NYC and further north/west, with some spots reaching and/or slightly exceeding 90 degrees. Cloud cover will increase on Tuesday as a weak low pressure approaches the region, producing scattered thunderstorms especially late in the day and into the overnight hours. Isolated/scattered storms will continue on Wednesday with slightly cooler temperatures, reaching the lower to mid 80s across the area. A few storms may be strong or severe, although no widespread thunderstorm/severe weather event is expected.


Thursday - Beyond: More Showers/Storms, Cooler Temps

By the late week into next weekend, the Greenland ridging that was entirely missing during the winter yet frequent during the summer months will make its return, as a strong 576 dm ridge builds into Greenland while cold from a strong polar vortex over Canada spills south towards the central US, bringing much cooler temperatures into areas that were hit hard by heat and drought this year. A cold front will make its way further east while the strong trough drops into the north central US, where widespread low temperatures in the 40s and even some 30s are expected. With the cold front moving east, rain and thunderstorms will make their way into the region by Friday further west and Saturday further east along with the potential for some severe thunderstorms. The GFS is currently the most progressive with the cold front, while the ECM and CMC are slower; given the trough axis focusing over the central US with blocking to its east over Greenland, the front will slow down as it reaches the eastern US, and I am siding with the slower ECM/CMC solutions for this time frame, with widespread showers and thunderstorms persisting on Saturday and into at least parts of Sunday.

Temperatures will reach the lower to mid 80s across the area, slightly higher in the immediate NYC area, on Thursday, with warmer temperatures for Friday in the mid to upper 80s from NYC and further north/west. Highs in the lower to mid 80s are expected again for Saturday and Sunday, perhaps staying below 80 degrees in some areas. The coolest temperatures will stay west of the region; with the front slow to exit the region, what's left of the cool air mass will be moderated by the time it reaches the area, with temperatures likely peaking in the upper 70s to mid 80s across the area for a short time behind the cold front, towards early next week, with drier conditions. The pattern until now has consisted of ridging in the western Atlantic and near the central US, resulting in slightly lower heights in the Northeast although there is more of an influence from the western Atlantic ridging, as seen with the lack of strong heat but frequent humidity and thunderstorm events. Although the trough is expected to weaken going into the middle of next week, no strong ridging is expected to build in accordingly with the pattern, with temperatures likely remaining close to average, somewhere around the lower to mid 80s range.

**No Update Posted 8/11/12**

Due to problems with the internet connection, no discussion was posted tonight. The blog will likely be updated with a forecast discussion early on Sunday, 8/12.

Reminder: The poll for changes in the 5-Day Forecast remains open until Wednesday, 8/15. The poll results will be taken into consideration when I make my final decision.

Aug 10, 2012 Noon Update

6:10 PM Update: The NWS confirmed that one of the earlier tornado warned storms did produce a tornado, EF0, near Great River north to Ronkonkoma in Suffolk county, Long Island. More information can be found in the NWS Public Information Statement.

5:30 PM: Earlier this afternoon, a line of strong to severe storms moved through most of the area except for northwestern parts of NYC and eastern NE NJ, affecting the rest of the area with heavy rain above 1 inch, locally as high as 2-4 inches. The most notable storms took place in Long Island and CT, however, with two tornado warnings issued in Long Island; the first near East Islip, and the second near eastern Suffolk county. So far, no tornado has been confirmed yet. Once the line of severe storms moved into Connecticut, however, a remarkably impressive feature developed east of Hartford, CT, almost resembling a tiny hurricane-like system while producing strong winds. This feature can be seen on the regional radar from 4:38 PM posted to the left, over Connecticut.

Behind the early afternoon storms, the latest regional radar does not show much storm activity outside of western NY/PA and far NE West Virginia. Additional thunderstorms are expected to develop towards central PA/NY, with scattered storms reaching the area as well, although the widespread heavy storms originally in the forecast for tonight and Saturday are no longer expected. Instead, scattered storms are expected to continue through Saturday, with some storms especially tonight capable of producing locally heavy rain.

This is the last update for today. The next forecast discussion will be posted on Saturday.