Santa, in his usual jolly self, replied, “Rain, dear, in many places; only some snow across the western States during my nighttime ride; heavy snow and blizzard conditions across parts of the northern Plains tomorrow, along with a chance of severe weather across the central Plains.”
A major winter-spring storm will be moving across the inter-mountain West today and then rapidly intensify as it heads toward the eastern Dakotas on Sunday (Fig. 1 and Fig. 2).
To the north of the storm track, heavy snow and blizzard conditions are likely, especially across the high Plains of the Dakotas and western Nebraska (Fig. 3).
To the south of the storm track, warm and humid air, interacting with a strong jet stream and diffluent winds aloft, will increase the risk of severe weather. Hail and high winds are the most likely risks under a NOAA Storm Prediction Center (SPC) outlook for marginal severe weather activity (Fig. 4).
In between, there will a zone of mixed frozen wintry precipitation, including freezing rain and sleet. Parts of west-
central Minnesota are now under freezing rain warnings. Given that the SPC outlook indicates thunderstorms are possible as far north as the mixed frozen precipitation area, locally heavier icing is possible. And, if the thunder zone spreads even further north, which it could, given the expected negatively-tilted (northwest-to-southeast) upper level trough (Fig. 5), thundersnow is not out of the question. Thundersnow is Jim Cantore’s (meteorologist at The Weather Channel) apparent new weather favorite!
Once today’s early day rain pattern clears the East Coast, most areas to the east and south of all this major storminess weather event (except for parts of the Great Lakes), should have great weather on Christmas Eve day and Christmas Day. It should be seasonally or unseasonably warm and pleasant in most areas with only limited chances of precipitation.
From my wife and I, Merry Christmas and Happy Hanukah to all of our readers and their families.
© 2016 H. Michael Mogil
Originally posted 12/24/16