December may kick off with snow, severe weather as storms ramp up across US

By Alex Sosnowski, AccuWeather.com Senior Meteorologist

November 24,2016; 8:40PM,EST

 

 

While the storm intensity has diminished a bit across the United States during Thanksgiving week, several potent storm systems are forecast during the end of November and into the first part of December.
"Five or six major storms will affect the nation into the second week of December," according to AccuWeather Lead Long-Range Meteorologist Paul Pastelok.
The jet stream, which is a high-speed river of air that occurs around the altitudes that planes fly, will amplify. The jet stream will transform from its west-to-east setup this week to a very convoluted setup next week.

As this happens, storms will increase in intensity after moving inland from the Pacific Ocean, much like that which occurred for a brief time in mid-November. However, this time more than one potent storm will evolve.
On average, the area from the coastal Northwest to the northern and central Rockies can expect a storm with rain and mountain snow of varying intensity every other day.
"Of these half-dozen or so storms, two or three will bring drenching rain to the Southeastern and Northeastern states," Pastelok said.

The storms will gradually ease the threat of new wildfires igniting and may help to extinguish existing wildfires in the Southeast.
Most of these storms will bring the potential for an inch of rain at the local level, not only in the South, but also in the Northeast. Both areas are experiencing abnormally dry to exceptional drought conditions.
"One or two of the storms could strengthen quickly enough and grab enough moisture to bring some rainfall to parts of the central and southern Plains," Pastelok said.
This portion of the Plains was sliding into abnormally dry and moderate drought conditions in recent weeks.
The storm systems will pose hazards ranging from wintry weather to severe thunderstorms.
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"We expect most of the storms to track roughly from the South Central states and toward the Great Lakes and interior Northeast over the next two to three weeks," Pastelok said.
A storm or two can also dip far enough to the south along the Pacific coast to bring cold air with rain and mountain snow to the Southwest, including parts of Southern California.
"The first storm with the potential to bring wintry travel to the passes in Southern California and along Interstate 40 in Arizona will span Saturday night, Nov. 26, to Monday morning, Nov. 28," according to AccuWeather Senior Meteorologist Henry Margusity.
Included in this slippery travel alert are Donner Pass, along I-80, and Tejon Pass, along I-5, both in California.
While this track favors rain over snow in much of the Northeast, it can produce rounds of heavy snow or a wintry mix from parts of the northern Plains to the Upper Midwest.
Should one of the storms track farther east, snow could be pulled closer to the coast in the Northeast.
The extreme nature of the pattern could also pump enough warm and humid air up from the south to increase the chance of thunderstorms and perhaps severe weather.
The severity of the thunderstorms in the late fall and winter months is less dependent on daytime heating and more dependent on the strength of the storm system, when compared to the spring, summer and early autumn.