Nov 20, 2012: Winter Approaches; Storm Next Week

Forecast Highlights:

Three more days of mostly to partly sunny skies and similar temperatures are expected in time for Thanksgiving day, with dry conditions and highs in the low to mid 50s expected. By this weekend, the pattern will begin to change as the cold air that has been building up in Canada drops into the US more frequently, starting with a much colder weekend followed by a storm around the middle of next week.

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Update: The pattern outlook will be posted on Wednesday afternoon instead of tonight.

Tonight - Friday: Mostly Sunny, Warmer

The current zonal pattern continues through Friday, with mostly to partly sunny skies expected to continue while high temperatures remain in the low to mid 50s. Mostly sunny skies are expected for Thanksgiving day as well, with temperatures on Friday slightly warming up with more locations in the immediate NYC area reaching and exceeding 55 degrees.


Friday Night - Monday: Colder, Windy

Since the early November snowstorm, a dry pattern took hold, with little variation in temperatures since a cold front came through early last week. Changes in the pattern are unfolding, however, and will be discussed with Wednesday's long range pattern outlook in more details. The first noticeable change is the strong cold air trapped in Canada making its way into the United States more frequently; the first occasion will be this weekend, with a transient cold air mass with 850mb temperatures dropping to approximately -8C. This will result in much colder temperatures for this weekend, along with stronger NW winds expected for Saturday. Highs are expected to reach the low to mid 40s inland and the mid to potentially upper 40s for the rest of the area, with overnight lows in the low to mid 20s inland and mid 20s to low 30s for the rest of the area except for NYC and the immediate coast, which will be slightly warmer. Isolated rain/snow showers are possible for the interior north and western parts of the area on Friday night and Saturday. Temperatures will slightly warm up going into early next week, with highs in the mid 40s to about 50 degrees likely.


Tuesday - Thursday: Storm Expected, Impacts Uncertain

The first widespread storm across the region since early November is expected on the 26-28th, next Tuesday-Thursday, with a low pressure developing in the central US. Given that this is still a week away, the exact track is uncertain and cannot be narrowed down to a single solution, with a possible track range from the Great Lakes, which would bring warmer temperatures with rain followed by a cold front to the area, to a track near the Mid Atlantic and southern Northeast, which would result in less warmth as well as the potential for snow, especially in the Northeast north of NJ and PA. Stay tuned for more information on this storm as details become clearer over the next few days.

A pattern outlook will be posted on Wednesday afternoon, discussing the expected changes in the pattern going forward into December.