Wintry Blast for the Northeast U.S.; short-lived cold spell for southwest Florida (H. Michael Mogil, CCM, CBM, NWA-DS*)
Well, folks from the southern Appalachians, across parts of the mid-Atlantic, and throughout New England are getting ready to experience said WINTER. A massive winter storm is developing along the Carolina coastline and will be moving to near Cape Cod by tomorrow (Dec. 17, 2020) morning (Fig. 1). At 10:00 a.m. E.S.T. today, Cape Hatteras, NC was reporting a temperature of 64 degrees, while Richmond, VA, just under 200 miles to its northwest, was a chilly 34. It is this type of temperature variation that provides the energy for winter storm development.
Forecasts are now calling for inland snows of 18 to 24 inches, a relatively narrow band of mixed wintry precipitation to its southeast, and then an 
area of heavy rainfall along coastal sections south of central New Jersey (Fig. 2 and Fig. 3). A zone of storm force winds (39 miles per hour or more), can be expected near the coast from Maryland to southern New England. Storm force winds are comparable to those of tropical storms. Where the winds and snow combine, blizzard conditions are not out of the question.
The wintry precipitation will be ending in the mid-Atlantic by Thursday morning and across most of New England by Thursday evening.
Travel and delivery of Christmas mail order items will likely be impacted. There will also be many road and airport closures.
In the storm’s wake in these areas, below-average temperatures, coupled with gusty winds, will slowly give way to seasonally chilly conditions by the weekend.
The storm’s circulation pattern will allow northerly and northwesterly winds to push cold air well into the southeast, including south Florida. In the Naples area, Friday will see morning lows into the upper 40’s, with daytime highs only near 70 degrees. This one day shot of cold air (temperatures seven to eight degrees below seasonal average) will be quickly replaced by seasonal readings through the weekend into early next week.
© 2020 H. Michael Mogil
Originally posted 12/16/20
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