Saturday, October 29, 2011

Oct 29-30, 2011 Snowstorm Updates

Below, storm updates will be posted throughout the day on the historic October snowstorm currently affecting the region.

**If I lose power out of this storm, this blog will not be updated until power returns, which may take a few days.**

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10:35 PM: Snow Intensifies East of NYC, Ends Further West

The deformation band began making its way further east shortly after the last update was posted, and has now cleared all places to the west of NYC, where only light snow showers are currently falling and will end by 12 AM. The western edge of the heavy snow is currently over NYC into Westchester county and western CT, and continues to move further east. Moderate to locally heavy snow will fall across Long Island and southern Connecticut over the next 2-3 hours as the band continues to move further east slowly, ending from west to east. Additional light accumulations are expected with this band of snow, with NYC and Long Island likely seeing up to another inch, locally up to 2 inches, with southern CT likely seeing 1 to 2 inches. The heavier snow will end across the area between 12-2 AM.

This is the final storm update for tonight. If I have power tomorrow morning, I will post a short summary on the storm, including final snow totals and a short update on the forecast. A more detailed storm summary will likely be posted sometime this week.


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7:55 PM: Snow To Spread East Again

Over the last two hours, the deformation band remained stuck over western New Jersey, but instead of moving east, shrinked in place while places from NYC and further east continued to see rain mixing with snow/sleet at times, although there are reports of more snow and sleet mixing with the rain in NYC. In Long Island, rain continues to fall, while in western NJ under the deformation band, heavy snow continues to fall, with over a foot of snow reported so far. Heavy snow will continue in these areas for the next hour before calming down, while in the immediate NYC area, light to moderate snow will continue to fall over the next 2 hours before starting to weaken. Additional light accumulations of 1 to 2 inches are expected in the north/west suburbs of NYC, with up to an additional inch possible in NYC, before the storm ends.



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6:05 PM: Snow Calms Down, But Will Intensify Soon

According to the latest snow totals from the NWS, snow totals have exceeded 3-4 inches in most areas to the west and NW of NYC, with the highest report so far showing 9 inches in West Passaic county as of 3:30 PM, and since then, amounts most likely exceeded 10 inches in parts of NW NJ. Earlier this afternoon, with slightly over 1 inch of snow, Central Park broke the record for the snowiest October on record; the previous record was held by 1925 with 0.8 inch.

The deformation band, currently near western NJ, is slowly moving east, and with the dry slot over eastern NJ filling up with bands of heavier precipitation moving towards NYC, the north/west extent of the rain/snow line has likely been reached, and from this point and on the rain/snow line should begin to retreat slowly to the east. Rain is expected to begin mixing with snow again in NYC over the next 1-2 hours, and by 9 PM, a moderate snow is likely to fall in NYC, with intensifying snow returning in the rest of the immediate NYC area. It appears at this time that another 2 to 4 inches of snow should fall across most of the immediate NYC area, likely higher further north/west towards north central NJ, with additional light accumulations later on tonight for Long Island and heavier accumulations for southern CT.



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4:30 PM: Heavy Snow Continues; Records Broken Across Area

Over the last few hours, a steady heavy snow affected places north and west of NYC, while southern Connecticut, NYC and Long Island changed over to mainly rain, mixing with snow/sleet in some areas. Exact accumulations so far are uncertain, but most areas north and west of NYC have exceeded 4 inches so far, with amounts further inland probably near 6-10 inches of snow so far.

A short break in the precipitation is approaching NYC and western Long Island as the deformation band, currently over Pennsylvania and western New Jersey, will continue to gradually move east. Parts of eastern NE NJ and southern Westchester counties may mix with and/or change over to light sleet/rain for a short period of time. The deformation band will then move into all of northern NJ and SE NY by at least 6 PM today, which will bring heavy snow to these areas again, and as the storm continues to move east, the deformation band will spread east, reaching the rest of the immediate NYC area this evening, with places currently seeing rain/sleet mixing with and changing over to snow. Another several hours of heavy snow are expected, followed by the snow tapering off around 12 AM from NYC and further west. Long Island and southern CT will continue to see heavy rain and strong winds for the short term, with snow mixing in by the evening and early overnight hours. Additional light accumulations are possible.

This is a VERY dangerous storm, and must not be taken lightly. The heavy wet snow will bring down trees and power lines, and power outages are possible for days. At this time, my updated forecast is for a storm total of 8 to 15 inches of snow in NW NJ/Orange county, 7 to 13 inches in the rest of NE NJ and SE NY, 2 to 5 inches in NYC, 1 to 4 inches in Long Island and 4 to 10 inches in southern CT. I will continue to post updates on this historic October snowstorm as long as I still have internet connection.


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12:10 PM: Heavy Snow Starts To Accumulate


Heavy precipitation spread into the area 1-2 hours earlier than expected, and with temperatures aloft below freezing, all locations west of NYC are now seeing moderate to heavy snow, with a mix of snow and rain falling in NYC as well. With heavy bands of rain still forming off the coast and moving into the cold air mass, the snow is unlikely to weaken in the short term, and at this rate, accumulations of up to 1-2 inches are expected west of NYC by 2 PM, possibly a little higher further west towards NW NJ. Until at least 3 PM, however, the snow can still mix with and occasionally fall as mainly rain under lighter precipitation in eastern NE NJ, southern Westchester county, and NYC.

The coastal low is still off the Mid Atlantic coast, and will continue to intensify while moving up the coast. While it may appear that the storm is quickly moving out, the intensifying low pressure will keep precipitation in place for a longer period of time. Once the low is near new Jersey's latitude, a deformation band of heavy snow will form over eastern Pennsylvania and New Jersey, extending the duration of the heavy snow while bringing the potential for thundersnow. After 3-4 PM, heavy snow will be the main precipitation type in northern NJ and SE NY, with a rain/snow mix in NYC and southern CT and heavy rain/thunderstorms in Long Island. The snow will continue to fall through the early overnight hours, ending by 12-3 AM across the area. With the heavier precipitation already staying over the area, it is possible that accumulations may have to be adjusted a little upwards in the immediate NYC area with the next update depending on how far north the warmth advances before colder temperatures move in and stick around for the night.



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10:55 AM: Snow Approaches; Slightly Increased Snow Forecast

As precipitation approaches the area from the southwest, the entire area is cloudy, with light rain affecting most of the area, mixing with light snow west of NYC. The latest regional radar to the left shows that steady precipitation is slowly moving into central/northern Pennsylvania and northern New Jersey, with heavy rain alling further southeast towards Virginia and the Delmarva Peninsula. The precipitation will continue to move to the north, with rain spreading across the entire area by 11 AM-12 PM.

The coastal low is currently near eastern Virginia, and is intensifying quickly while moving to the NNE. The intensifying low will result in heavier precipitation developing in the Mid Atlantic, moving towards the area by this afternoon, and the storm will pull the colder air towards the low pressure, changing over areas further east to snow. By at least 2-3 PM today, western NJ and Orange county will see heavy snow, while the north/west suburbs of NYC begin to mix with snow. With the heavier rain in the Mid Atlantic moving into the colder air mass over the area, heavy snow bands will begin to develop over northern New Jersey and eastern PA late this afternoon, and with the intensifying low pressure, thundersnow is even possible in parts of the area. The rain/snow line will gradually move further east, with the north/west suburbs of NYC changing over to a heavy wet snow betwen 3-6 PM, with the changeover closer to 6 PM for areas closest to NYC. Meanwhile, heavy rain will fall in Long Island and southern CT, with thunderstorms possible and winds gusting up to 50-60 mph.

By this evening, New York City will also change over from rain to a heavy, wind-driven wet snow, with southern Connecticut also changing over to snow and parts of Long Island starting to mix with snow. The snow will have difficulty accumulating at first in NYC due to the wet ground and warm ground temperatures, but with at least a 6 hour period of moderate to heavy wet snow expected, some accumulations are expected, and NYC will see at least up to 1 inch of snow, with parts of the city potentially reaching 2 inches. If these accumulations verify, this will be the snowiest October in Central Park's recorded history. The snow will end west of NYC by 12-1 AM, and east of NYC around 1-4 AM.


Accumulations: The western models with yesterday's outlook trended towards the east, towards a solution in between the two scenarios but slightly leaning a bit further east. With all of the right ingredients in place, this storm will bring significant snowfall accumulations, with several inches of snow expected in places where snow almost never falls in October. My final accumulation call is for up to 1 inch of snow in Long Island, trace to 2 inches in NYC, 3 to 5 inches of snow in the immediate north/west suburbs of NYC and in southern CT, 4 to 8 inches towards western Bergen/Rockland counties, and 7 to 12 inches of snow in NW NJ and Orange counties. Amounts may be higher than mentioned above in the higher elevation.s

Stay tuned for more storm update throughout the day on this storm.

1 comment:

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