Dec 3: Cold, Winter-Like Pattern To Last

Note: The 5-Day Forecast was updated for the area tonight except for Long Island/S CT.

---------------------------------------------

The first day of meteorological winter brought an end to the mild pattern we've been seeing in November that started back in March, and yesterday felt much more winter-like, with high temperatures in the upper 30s to lower 40s inland, upper 30s to mid 40s in the immediate NYC area, and in the lower to mid 40s for Long Island/S CT, nothing in comparison to the 50s and 60s on Wednesday.. Today was another cold day, with mostly cloudy skies and temperatures slightly colder than yesterday, in the upper 30s to lower 40s across the entire area, which was slightly colder than originally expected.

With the pattern setting up, generally partly to mostly cloudy skies will remain in the area through at least Wednesday or Thursday, with the DC-NYC corridor being the only area out of the entire region to stay dry during this time frame, but the cold will be the main story, as temperatures will stay below average through the first half of December, if not even longer, with well below average temperatures also possible, the longest extent of below average temperatures the area has seen since January.

While there is uncertainty on the longer range beyond mid December, it is possible that December may bring the most sustained cold of the winter, with December being the main wintry month for the Mid Atlantic and Northeast as the winter outlook discussed. More on this will be discussed in the "Long Range Outlooks" page over the next 1-2 weeks.


Tomorrow's Outlook:

Tomorrow will be a mostly to partly sunny day across the area with a NW wind expected. Breezy conditions may be possible at times. High temperatures will be in the upper 30s inland with a few lower 40s possible and in the upper 30s to lower 40s for the rest of the area.

Looking across the region, a weak Alberta Clipper will bring light to moderate snowfall to the southwestern parts of the Ohio Valley while moving southeast. While this clipper will stay well to the south of NYC, with the first snow of the winter falling in places such as southern Virginia, it will help set up the pattern for next week.


Saturday Night - Sunday: Snow In Virginia, Dry In NYC

Tomorrow night will again be mostly clear to partly cloudy, with even colder low temperatures, in the lower 20s inland, potentially upper 10s if there is less cloud cover than expected, lower to upper 20s N/W of NYC and in S CT, and upper 20s to lower 30s in NYC.

The Alberta Clipper previously mentioned will move through the Carolinas tomorrow night, bringing a light mixture of snow and rain to northern North Carolina and southern Virginia, where light snow accumulations are possible. Due to the strong blocking pattern, the clipper will not be able to move further north and affect places north of Washington DC. The clipper will move offshore by Sunday.

This clipper, however, will help pull in an even colder air mass into the area. High temperatures will be in the lower to mid 30s inland and in the mid to upper 30s for the rest of the area, making it the first day of the winter with high temperatures below 40 degrees in parts of the area.


Monday - Tuesday: Mainly Cloudy, Cold And Breezy

On Sunday night, the clipper, which will be well offshore, will be forced to turn north and northwest again, and is expected to rapidly intensify in this time frame. By Monday morning/afternoon, the storm will strike Nova Scotia as a powerful 960 mb low pressure, equal to that of a Category 2 hurricane! A large trough meanwhile will set up, covering nearly all of the East Coast.

The storm will produce snow for Maine, however it will then slow down significant while moving WNW, with the cold air digging even deeper into the East. Monday and Tuesday will gradually become colder, with low temperatures remaining in the upper 10s to lower 30s across the area and highs in the lower to upper 30s. Due to the storm, mostly cloudy skies are expected with breezy conditions each day, and an isolated snow shower cannot be ruled out each day.


Wednesday - Thursday: Arctic Air's Deepest Extent

On Wednesday, the worst of the arctic air mass will affect the area as the storm starts to exit and leads to quieter conditions in the region. 850 mb temperatures are likely to reach -14c, which will lead to high temperatures likely in the upper 20s to mid 30s across the area, with even NYC struggling to make it above the freezing mark. Low temperatures on Wednesday night could reach the mid to upper 10s inland, upper 10s to mid 20s north and west of NYC, and in the mid to upper 20s in NYC in the colder case scenario.


By Thursday and Friday, the cold air mass will start to moderate, however a storm coming out of the Great Lakes region may bring precipitation in the form of snow to the region, followed by another potential round of arctic air for the end of the weekend. Stay tuned for more details on the longer range.