Jan 17, 2012: Some Snow Thursday Night

After last night’s update, a widespread mix of light snow and sleet continued to affect most of the area through at least 12-1 AM, when warmer air began to move in and precipitation began to change over to rain. Most places ended up with a coating of snow and sleet, even in parts of NYC and Long Island, although light accumulations of up to 1 inch were observed in Orange county, NY, with up to 2-3 inches in parts of interior southern Connecticut. Temperatures peaked near the upper 30s to lower 40s inland and the mid to upper 40s across the rest of the area, although temperatures are expected to rise into the mid to upper 40s across the area, possibly near 50 degrees in parts of the NYC area, by 12-1 AM as the cold front moves through the area.

Colder temperatures will return into the area behind the cold front, with temperatures tomorrow steady in the mid to upper 30s across most of the area along with windy conditions, gusting up to 30-40 mph late tonight into tomorrow morning. The next storm will affect the area on Thursday night, when a more widespread light snow is likely to affect the area, ahead of another storm on Saturday which is more uncertain but could include some frozen precipitation as well.

Tomorrow’s Outlook:

As previously mentioned, windy conditions are expected especially in the morning tomorrow, with winds gusting up to 30-40 mph at times in parts of the area. Partly cloudy skies are expected across the area, with temperatures steady, if not slightly rising, into the lower to mid 30s inland and the mid to upper 30s across the rest of the area, possibly reaching the lower 40s near NYC and parts of Long Island.

Thursday Outlook: Colder, Some Snow

With a high pressure moving towards the region, mostly clear skies are expected on Wednesday night with temperatures dropping into the 10s for most of the area except for parts of Long Island and NYC, which will stay in the lower 20s for lows. Temperatures on Thursday will warm back up into the lower to mid 30s inland and the mid 30s across the rest of the area, although cloud cover will increase as a low pressure approaches the region from the west. This low pressure will produce widespread snow showers across the region on Thursday night, including the area. Most of the snow will fall to the north and northeast of NYC as the low pressure will track north, however temperatures are expected to be cold enough along with enough precipitation to support at least light snow showers for most of the area. Long Island could see more of a borderline situation as onshore winds may be enough to warm temperatures above freezing, resulting in mixing with rain, although some snow is expected in Long Island as well.

There are two main scenarios for this storm right now; the first is where the storm quickly moves through the region with almost the entire precipitation staying north, with light snow affecting NW NJ, skipping through the NYC area with more snow dropping into southern CT/Long Island, in which case NYC would only see isolated flurries. This scenario is supported by some GFS runs and the ECMWF. The second scenario, supported by the CMC and the NAM, is where more precipitation affects the NYC area, with at least 0.1″ or more QPF from the immediate NYC area and further north/east. This scenario would bring widespread light snow, with accumulations of 1-2 inches possible in the immediate NYC area into southern Connecticut. Forecasting snow has been difficult this year especially due to the lack of any snow events so far, and the model guidance has not had a good handle on some storms this winter. For now, I am going with a slightly lower snow potential, although it does appear to be likely that most of the area does see snow, and for now I am going with a 60% of snow across the area on Thursday night, with accumulations up to an inch possible. The accumulations are uncertain and subject to change, and could end up higher or lower than expected. Stay tuned for more information on this light snow event.

Friday – Weekend: Another Storm On Saturday

With Thursday’s storm moving out, Friday will bring partly sunny skies across the area with breezy winds expected again, with gusts up to 30 mph possible in parts of the area. Temperatures will be similar to those of Thursday, reaching the lower to mid 30s inland and the mid 30s across the rest of the area. Cloud cover will increase again overnight, however, as another storm approaches the region. There is a model consensus for a storm to affect the area on Saturday, although details vary on the models, with the CMC and ECMWF showing a snowstorm for parts of the area and the GFS and NAM/DGEX favoring a further north and warmer scenario. While the southern scenario is possible, the trends this year have frequently been to the north and/or west with storms, and considering that there is not much to prevent this storm from tracking further north, I am leaning towards the northern track scenario, where the storm starts out with some snow in the area but changes over to rain for the rest of the storm, with the majority of the snow focusing over New England, where several inches of snow are possible. This forecast is still not final, as there is some time for changes with the storm, and while less likely, the potential is there that the southern scenario verifies and parts of the area get a snowstorm.

Beyond Saturday, details become more uncertain as the models begin to have more difficulties with handling the set up, although the outlook is likely to remain unsettled through Sunday and into the start of next week, with mostly cloudy skies likely along with the risk of some showers either on Sunday or Monday. Temperatures will warm up as well, reaching the 40s across most of the area for highs. Going forward into next week, however, as my long range discussions over the last week have mentioned, the cold air in Canada weakens and retreats north with a zonal flow in place, and while not the entire time frame will be warm, as some storms will move through keeping temperatures closer to average, although at least once, if not more, temperatures have the potential to reach and/or exceed 50 degrees next week. A more detailed long range outlook, along with an update on February’s outlook and whether cold and snow chances will increase or not, will be posted with Friday’s update.

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