Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Valid 12Z Sat Jan 04 2014 - 12Z Mon Jan 06 2014
...The next winter storm will bring heavy snow to the Middle
Mississippi/Ohio Valleys and Lower Great Lakes on Sunday...
...Icy conditions are possible over the Deep South and northeastern tier of the country...
The upper pattern across the nation will continue to be dominated by
arctic intrusions bringing reinforcing shots of cold air to the country.
Forecast models remain consistent in carrying the polar vortex into the northern tier of the U.S. while carrying it eastward in time.
Many locations may see their temperature readings drop to near record values.
By Sunday, afternoon temperatures across the Northern Plains/Upper Midwest may linger in the negative 10s/20s with lows plummeting that night to near -30 Fahrenheit.
The broad pressure gradient setting up over the region will allow gusty winds to persist which will lower wind chill temperatures to very dangerous levels.
Incredibly, it may feel as cold as -50 to -60 on Sunday night over sections of the north-central states with the frigid air remaining in place into early next week.
As the vortex shifts eastward, the polar air will begin to affect the Great Lakes and Ohio Valley with temperatures plummeting rapidly.
While the air mass will modify, temperatures will remain downright cold with the forecast high in Chicago, IL being only -11 on Monday.
A strong frontal boundary surging eastward ahead of the polar air mass will become rather active as it intercepts increasing amounts of low-level moisture.
A broad area of moderate to heavy snow will be possible from
southern Missouri northeastward into the Ohio Valley and Lower Great Lakes region.
The WPC winter weather desk suggests this area can expect anywhere from 6 to 10 inches of snow through early Monday with lighter amounts surrounding this region.
Given the cold air currently in place over much of the eastern third of the country, there may be issues for freezing rain during the next couple of days. This will be particularly true from the Deep South northeastward along the Appalachians and into the interior New England. The cold air at the surface will initially be stubborn to scour
out. The residual warm layer above this sub-freezing surface will lead to periods of freezing drizzle/rain with an eventual changeover to rain.
A wet period is expected across south Florida as moisture return commences during the period. A frontal boundary south of Cuba is forecast to quickly lift northward toward the Florida Keys which will begin spreading moderate to heavy rainfall to the region. Locations further north across Florida should expect much drier conditions as the frontal lift does not work its way northward along the peninsula.
Elsewhere, with the exception of some orographically enhanced snow showers across the Northern/Central Rockies, the western states can expect tranquil weather through early Monday.