Turkey in the snow?

Turkey in the Snow?

MID-ATLANTIC AND NORTHEAST MAY SEE FIRST 

WIDESPREAD WHITE THANKSGIVING SINCE 1989

7:30 PM EST 11/23 - UPDATED - Discussion of scenarios below. 
NOAA Snow Probabilities: Moderate (40%) chance of 4" for Northeast US

1:05 PM 11/23 (By the Kentucky & Winter Stormcast Teams) Although the Thanksgiving holiday period is finally arriving, Mother Nature shows no signs of taking time off as the potential is increasing for a significant weather event that could snarl one of the busiest travel days of the year.

THE SITUATION: Our team first identified the potential for a "White Thanksgiving" in an October 25 post, due in part to data showing a record high snow-cover for Siberia and the downstream effects that large Arctic highs would have coming across the Pole. Now in present day, numerous medium range model runs support a significant winter storm occurring on Wednesday into Thanksgiving morning near the East coast. 

• The areas which may see notable to significant impacts from this system extend from South Carolina to the Mid-Atlantic, into the Northeast all the way to Maine. 
• As with all storm forecasts more than 72 hours out, we expect considerable variance between forecasted data and outcomes, until shortly before the event begins.
• The timing of this system creates additional concern for the traveling public, hence we are outlining scenarios early to help identify which pattern will prevail.

SCENARIO A: OUR GOOSE IS COOKED. An area of low pressure develops in the northern Gulf and moves along the East coast, bringing Gulf moisture while drawing in Atlantic moisture. The system would tap cold air from a snow-cover influenced surface high in western PA/NY. 

• This track would hug the shoreline, bringing heavy rain and tidal flooding to coastal communities and heavy snow in the interior. 
• As temperatures fall into the 30s through the Mid-Atlantic and Northeast, rain would change to snow in the major cities and continue heavy overnight, producing  a major snowfall to a majority of the Northeastern states. 
• CNN features long lines of weary travelers stuck in airports.

The latest liquid projections by the US Global Forecast System for BWI airport show why there's much concern for Scenario A. Nearly 1.0" of liquid falling as snow would be a major problem.

SCENARIO B: BETTER LEAVE EARLY ANYWAY. The storm develops weaker and further east than in Scenario A. This would produce far less precip for the Carolinas, Mid-Atlantic and Northeast. 

• However, colder air will be more available, as northwest flow would rush in behind the departing storm. Coastal areas would see a cold rain or wet snow that has trouble sticking until after nightfall Wednesday. 
• The bulk of energy would affect northern states, especially New England while the Mid-Atlantic is only brushed with light accumulations. 

SCENARIO C: CANCEL THE SNOWSUIT SEARCH! Strength and influence of the Great Lakes system on Tuesday nudges any coastal Low pressure away from the eastern seaboard, in tandem with surface high pressure to the north. 

• This would bring only brief light precipitation to coastal areas, little or no precipitation to major cities and minimal impacts on Thanksgiving travel.

Our Winter Stormcast Team will be frequently monitoring the latest changes and updating here as data becomes available. Our next update is planned for Monday where we will narrow the scenarios to 2 options and begin discussing precip and snowfall ideas.

(Report by the Kentucky Team: Forecasters Kyle Jackson, Darius Mack, and Lead Forecaster Chris Reece. Additional content by Maryland Team members Mike Natoli, Connor Meehan, Joey Krastel and Rich Foot)