Southern tornado threat increases as West is blanketed in needed snow

CNN
 — 

A clash of two seasons will see an early winter blast meet record autumn warmth over the next few days – and that meeting will lead to a robust storm system with heavy mountain snow in the West and severe storms in the South.

“An active end to the (workweek) is in store for much of the country as a highly amplified upper-level trough swings eastward and triggers multitudinous weather hazards for areas west of the Mississippi River,” the Weather Prediction Center said.

Just as that system spreads east, another system will push into the Pacific Northwest bringing heavy rain, snow and high winds.

Winter weather alerts remain in effect for much of the Rockies where heavy snow will continue Thursday and temperatures will plummet.

“Strong and gusty winds from the north will also add to the wintry feel in these area in stark contrast to the warm and dry weather in recent days,” the prediction center said.

Salt Lake City soared to nearly 70 degrees Tuesday, but by Wednesday evening temperatures had fallen below freezing as the season’s first snow arrived. Snow is expected to continue across Utah, Arizona and Nevada on Thursday, and begin to push into Colorado, New Mexico, Wyoming, Nebraska, and South Dakota.

Hard freeze watches and warnings are also in effect across Utah and California as temperatures are expected to significantly dip Thursday night into Friday, dipping down into the mid-20s.

By Friday morning, Denver is forecast to be more than 50 degrees colder than it was on November 1 – with at least 1 to 2 inches of fresh powder.

Sign up here for weekly weather forecasts >>>

Cold air from the West will interact with the record warmth across the Central Plains and Midwest allowing for the development of severe storms late Thursday into Friday morning.

The Storm Prediction Center has issued a slight risk (level 2 of 5) of severe storms for parts of Texas, Oklahoma and Kansas, with a marginal risk (level 1 of 5) surrounding this area. “Damaging gusts, isolated large hail and a marginal tornado threat will be possible,” the prediction center warned.

Many of these storms will fire up during the overnight hours, adding to the risk. Nocturnal tornadoes tend to be more deadly than those that happen during the day because people are sleeping and are less weather-aware.

Storms could continue into Friday morning with additional severe activity ramping up in the afternoon hours.

An enhanced risk (level 3 of 5) of severe storms has been issued for 9 million people across parts of Texas (including Dallas and Fort Worth), Oklahoma, Arkansas and Louisiana.

Tornadoes, some of which could be significant (EF2 or greater), damaging winds and large hail will threaten the region Friday.

Another 27 million people surrounding this enhanced risk area are also at risk, (level 1 or 2), for severe storms Friday. This area includes the Texas cities of Houston, San Antonio and Austin, as well as Oklahoma City, Kansas City, Kansas, and Wichita, Kansas.

Heavy rain will accompany the threat of severe weather.

Most areas will see up to 2 inches of rain. There could be isolated amounts that are even higher if storms linger or train over the same areas for longer periods.

While much of the central US is also suffering from drought and needing rain, excessive rainfall rates could lead to the flooding of the hard, dry ground, especially across the Ark-La-Tex region, according to the Weather Prediction Center.

The series of winter storms will continue with a surge of precipitation beginning late Thursday through the weekend, building the snowpack across many drought-stricken Western states.

As much as 15 to 30 inches of fresh snow is possible in the higher elevations of the Cascades, Rockies and Sierras through Sunday, while highs in cities including Seattle, Salt Lake City and Portland, Oregon, will be 10 to 15 degrees below seasonal averages.

Highs across several major cities in the Northwest will be in line with temperatures typically seen in early January – not early November.

As much as 5 to 10 inches of new precipitation is forecast across the Pacific Northwest over the next seven days.

The increase in moisture is welcome as nearly 75% of the Western US is under some level of drought, with one third of the Pacific Northwest experiencing severe drought conditions.

November is the second-wettest month of the year in cities including Seattle and Portland. The rainfall potential will also increase as far south as Southern California beginning late this weekend and through next week.