With a weak low pressure moving through the northern NE today, temperatures were once again above average across the area, with partly cloudy skies observed. High temperatures reached the lower 50s inland and the lower to mid 50s across the rest of the area, approximately 5 degrees warmer than average. Colder temperatures will return into the region tomorrow as a strong high pressure moves through, although temperatures will still be near to slightly above average.
Meteorological winter officially began yesterday, on December 1st, yet the pattern continues to resemble November, with temperatures once again expected to pass 60 degrees across the area early next week. There will be some changes in the pattern, with more frequent cold temperatures expected starting late next week, but this period of colder temperatures is not a pattern change, but only a temporary break from the overall mild pattern.
Tomorrow will bring slightly colder temperatures as a high pressure moves into the region. With sunny skies expected, high temperatures will reach the mid to upper 40s inland, upper 40s to lower 50s in the immediate NYC area, and the upper 40s across Long Island and southern Connecticut. These will be some of the coldest high temperatures since mid November, yet these temperatures are still near to slightly above average for much of the area.
Sunday - Wednesday: Warming Up; Rain Returns
With no changes in the pattern yet, as well as a low pressure near the central US, yet another ridge will build into the eastern US. This ridge won't be as strong as previous ones the region has seen, although it will provide well above average temperatures once again. Sunday will bring mostly sunny skies with highs rising into the mid to upper 50s across the area. The warmest day is likely to be on Monday, with partly cloudy skies and high temperatures reaching the lower 60s across most of the area. Parts of the immediate NYC area may get close to the 65 degree mark.
By Tuesday, the waves of low pressure in the central US will shift east towards the region, bringing increased cloud cover with scattered showers developing by the afternoon and evening. Temperatures are once again expected to peak in the upper 50s to lower 60s across the area, and if the timing of the rain and clouds is slower than currently expected, temperatures may be slightly warmer. There are some model differences with the timing of the storm, with the CMC showing a front on Tuesday followed by a separate Thursday system, the GFS bringing the front through on Tuesday night, and the ECM on Wednesday night. For now, I am leaning with a slower and slightly further west scenario than the GFS, with rain developing on Tuesday night and lasting through at least Wednesday night, potentially heavy at times during the day on Wednesday and on Wednesday evening, with the front then moving through, although it is possible that the timing could be slower or faster. The potential may be there for 1 or more inch of rain in parts of the area out of this storm, and rain alerts may be issued within the next few days. Stay tuned for more information on the mid week storm.
Thursday and beyond: Colder Temperatures Return
Behind the storm, a strong cold air mass will drop from Canada towards the northern US. Although the ridge in the southeastern US will weaken, it will only weaken, not dissipate, and is expected to remain off the coast. As a result, although colder temperatures are expected, the stronger cold will not reach the area in the late week. High temperatures are expected to end up slightly below average, reaching the upper 30s to mid 40s across the area, with lows likely in the mid 20s to mid 30s. Beyond the late week, an overall colder pattern is expected through at least December 15-20, although the cold won't be sustained the entire time with occasional moderation in the temperatures, and snowstorms will likely continue to focus over the Ohio Valley, Great Lakes and parts of the interior Northeast. As my winter outlook will discuss tomorrow, however, what we are seeing now is likely not a pattern change, with a moderation in temperatures possible afterwards once again.