Dec 10: Rain/Wind For Sunday, Wintry Mix Inland

Yesterday was the coldest day for the area so far this winter, with high temperatures in the mid to upper 20s inland and in the upper 20s to lower 30s for the rest of the area. Temperatures this morning were very cold, in fact the interior parts of the area saw low temperatures in the mid to upper single digits! Today was slightly warmer, but cloudy skies took place as a clipper to the north of the area produced a steady light snow north and NE of NYC, leading to light accumulations in southern Connecticut and SE NY.

Temperatures will continue to warm up as the cold air mass is pushed out and a storm tracks through the southern Great Lakes on Sunday, producing heavy rain and wind in the area, followed by increasingly colder temperatures, similar to those of yesterday. The cold will moderate by the middle of the week, but by the 16th the models are hinting at a weak storm potential which may need to be watched for potential impacts on the region.


Tomorrow's Outlook:

Tomorrow will be a partly sunny day with calm winds expected. High temperatures will be warmer than those of today, in the upper 30s to lower 40s inland and in the lower to mid 40s for the rest of the area.


Tomorrow Night - Sunday Night: Storm Brings Heavy Rain, Some Mix Inland

Early this week, when the models started showing the storm more consistently but led to a lot of confusion regarding the potential track, the ECMWF model, generally known for having a good performance rate, was the westernmost model, showing a storm track through the southern Great Lakes. While the other models were much more south/east, with the GFS showing a track right along the coast, the ECMWF ended up being the correct model, and the models all trended west towards its solution, which is now the expected one. For the last few days, I went with a very similar solution, expecting a track through the central Ohio Valley to the western Northeast, which was closer but a little southeast of the current model consensus.

Saturday Night: As a result of the above, when the storm moves in on Saturday night, due to a little cold air in place, precipitation may start in the middle of the overnight hours as a light snow/sleet mix inland with rain for the immediate NYC area and further east. As 850 mb temperatures warm above 0c, precipitation in the typical Cold Air Damming areas in Pennsylvania and Sussex/Orange counties will see mainly freezing rain with some sleet/rain mixing in by the late overnight hours/early morning hours as temperatures start to warm up. I am considering whether to add a Sleet/Freezing Rain Alert for the interior parts of the area, which may be issued tomorrow morning for the overnight hours.

Sunday: With the primary low moving through the southern Great Lakes, it will pull a warmer air mass in, leading to high temperatures in the upper 40s inland and lower to mid 50s further east. There are expected to be two rounds of moderate rain, the first one being in the late overnight to early morning hours. Occasional light to moderate rain will take place in between, during the early afternoon, with temperatures warming up. Windy conditions are possible at times.

Sunday Night: The storm will try to get a secondary low going, with the area of low pressure extending SE, but will not be able to do so, and the storm will end up quickly intensifying over western NY on Sunday night while starting to move north/NNW into Canada. This will bring a cold front through the area in the evening hours, with another round of moderate, potentially locally heavy rain expected, with gusty winds at times. By the time that the rain ends, at least 3/4 to 1.5 inch of rain is possible. The rain will end by at least 12 AM as the cold front pushes the mild air out with colder air coming in. Temperatures will steadily drop from then until the morning hours, with a few rain/snow showers then possible.


Monday - Wednesday: Cold, Windy, Mainly Cloudy

By Monday, as the cold front continues to push east of the area, temperatures will stay steady from those of the morning hours, possibly rising a little, only to drop again overnight, with a few snow showers possible. As a much colder air mass returns into the region, conditions will be similar to those we saw early this week, with mainly cloudy skies along with scattered snow showers on Tuesday and Wednesday, windy conditions with gusts over 30 mph possible at times, and high temperatures in the lower to mid 20s inland, mid 20s to lower 30s in the immediate NYC area, and in the upper 20s to mid 30s in Long Island/S CT.

By Thursday, the cold is expected to weaken, however there is increasing uncertainty as the models are starting to show a low pressure moving from west to east that brings snow to the south of the area. While this is in the longer range and will change over the next few days, this time frame will be watched for a potential storm. Stay tuned for more details.