Jan 8, 2012: Mild Week Ahead

As a colder air mass moved into the region, much colder temperatures were observed today, with mostly cloudy skies and high temperatures reaching the lower 40s inland and the mid 40s across the rest of the area. Although these temperatures are noticeably colder, they are still several degrees warmer than average. Temperatures will continue to gradually warm up over the next few days ahead of a rain event on Wednesday night into Thursday, when temperatures will pass 50 degrees once again. Significantly colder temperatures will return by the weekend, with high temperatures struggling to reach the mid 30s for highs; although the pattern will eventually change towards more cold and some snow, the cold for this weekend is not a pattern changer.


Tomorrow's Outlook:


Tomorrow (Monday) will bring partly to mostly cloudy skies along with temperatures similar to those of today, reaching the lower to mid 40s across the area. A weak wave of low pressure will move through the Mid Atlantic in the evening and then south of the area overnight, bringing mostly cloudy skies to the area. The models are still showing different solutions despite this storm barely a day away, with the ECM and CMC models showing light snow with light accumulations for NYC, the UKMET and SREF have flurries, and the GFS and NAM keep precipitation well to the south of NYC.

The ECM and CMC are most likely too high with precipitation amounts, and I am going with a scenario somewhere between the UKMET and the southern solutions, with most of the precipitation staying to the south of the area with isolated rain or snow showers in parts of the area, especially focusing over NYC and further south/east, where more widespread snow showers are possible on Monday night. If there are any changes in the forecast, they will be mentioned tomorrow afternoon, although in the scenario that the storm does affect the area with more than flurries, little snow accumulations, if any, would fall.


Tuesday - Thursday: Warming Up, Becoming Stormy


As mentioned yesterday, a warm air mass will move into the region on Tuesday and Wednesday, bringing temperatures back to much warmer than average. Mostly to partly sunny skies are expected on Tuesday along with highs reaching the mid to upper 40s inland and the upper 40s across the rest of the area, with parts of the immediate NYC area especially near NE NJ reaching 50 degrees. Temperatures will slightly warm up on Wednesday, in the upper 40s inland and the upper 40s to lower 50s across the rest of the area, along with increasing cloud cover and the risk of an isolated shower west of NYC by the evening.

A cutoff low in the southern US for the short term will move northeast during this time frame, approaching the region. Although the exact track is still uncertain, there is high confidence with the storm's impact on the region, with the mild air mass initially in place preventing the storm from starting out with frozen precipitation south of central New England and the higher elevations of New York state, where a mix of light snow, sleet and freezing rain is possible at the start of the storm. Rain is expected to become more widespread especially after 11 PM across most of the area, with moderate rain lasting through the overnight hours along with temperatures slowly increasing towards the morning. The rain is likely to end sometime between 11 AM and 2 PM across the area, with mainly cloudy skies and isolated showers for the rest of the day along with temperatures reaching the lower to mid 50s across most of the area, much warmer than the average for this time of the year. At least 1/2 to 1 inch of rain is expected across the area out of this storm, with locally higher amounts slightly above 1 inch possible in some areas. Stay tuned for more information on the outlook for this time frame.


Friday - Weekend: Windy Start, Then Colder


A much colder air mass will move into the region behind the Thursday storm, with temperatures likely to end up near to slightly below average. There are two scenarios shown for Thursday night into Friday, with last night's ECMWF run suggesting the potential for scattered rain/snow showers on Friday. Although the forecast mainly appears to be dry, isolated showers are possible on Thursday night, with isolated rain and/or snow showers possible on Friday, with otherwise mostly cloudy skies and breezy conditions, as winds may gust near or above 30 mph. With the cold air mass moving into the region throughout the day, temperatures will slightly rise into the mid 30s to lower 40s across the area for highs, dropping by the late afternoon and evening.

Last night's update mentioned that some models showed a storm potential, although it was uncertain whether there would actually be a storm or not. With the models starting to reach a better consensus for Wednesday's rain event, a storm is ruled out for the weekend, with cold temperatures expected instead, although the possibility of isolated flurries in parts of the region cannot be ruled out as the GFS model suggests. There is some uncertainty with the timing of the coldest air, which the GFS shows for Sunday into Monday, the ECM shows for Saturday into Sunday, and the CMC has for Friday night into Saturday. For now, I am considering the CMC solution as an outlier for bringing the cold air in too quickly, and although it is still uncertain whether Sunday or Monday ends up as the coldest day, either day could bring high temperatures in the 20s to lower 30s for most of the area given the intensity of the air mass, along with low temperatures potentially in the 10s to mid 20s. There is more uncertainty beyond the weekend due to the time range, although it appears that temperatures will slightly warm up for the first half of next week although staying chilly compared to the recent mild temperatures, with dry conditions likely to last through at least Monday and/or Tuesday.