lisa 2a
Rain and snow for Pacific Northwest as Lisa continues to strengthen
02:31 - Source: CNN
CNN  — 

A potent storm system moving in from Canada will deliver snow to all 11 Western states in the next 48 hours, as well as trigger a tornado threat in the South, as the cold Arctic air meets the autumn warmth.

“A potent cold front will usher much colder air through the Western US while delivering a round of heavy snow across the higher elevations during the next couple of days,” the Weather Prediction Center said.

Nearly two feet of snow could blanket parts of the West

Snow will fall across much of Idaho and western Montana on Wednesday, bringing slippery road conditions and low visibility.

“As the cold front traverses the region later this morning, it will likely bring a brief period of moderate to heavy snow showers and gusty westerly winds to portions of north-central and southwest Montana,” the weather service office in Great Falls said.

They warn that strong winds could result in blowing snow that will limit visibility to less than a half mile.

Across the Sierra, one to four inches of snow is forecast, with up to an inch for the lower elevations.

As the cold front advances east, the Rockies will also get hit hard with heavy accumulating snow. This snow will be a welcomed sight for most as nearly 75% of the West is in drought conditions.

“Widespread snow totals of 10 to 20 inches are expected in the mountains with this storm, with some locales in the San Juans approaching 32 inches. Gusty winds will contribute to making this a significant fall storm,” the weather service office in Grand Junction said.

Behind the front, gusty winds and much cooler temperatures will settle in briefly.

Highs across portions of Colorado, which are reaching the mid-50s to low-60s on Wednesday, will only manage to get into the 30s on Friday.

Tornado threat returns to the South

As the storm ejects out of the Rockies and into the Plains, the cold front will be less of a wintry concern, and more of a severe weather threat to millions.

Severe weather will be possible Thursday and Friday across the South.

Very heavy rain will fall across most of the Plains states, Midwest and Deep South as the system strengthens.

On Thursday, the Storm Prediction Center highlighted an area stretching across portions of Texas, Oklahoma and Kansas for a risk level two of five for severe weather.

“All hazards will be possible including up to large damaging hail, damaging wind gusts,” the weather service in Norman, Oklahoma, said, adding they “cannot rule out a few tornadoes.”

Many of these storms will be firing up during the overnight hours, adding to the risk even more.

Nocturnal tornadoes tend to be more deadly compared to tornadoes that occur during the day because people are sleeping and are less weather-aware.

By Friday, the severe weather threat shifts to the east, covering much of Texas and portions of Oklahoma, including the most populated cities of each.

More than 21 million people face the heightened severe weather threat on Friday including the cities of Dallas, Houston, Austin and San Antonio.

“All severe hazards appear possible, though damaging gusts and a few tornadoes will be the main concerns through Friday night,” the Storm Prediction Center warned.

Heavy rain will accompany the threat of severe weather.

Most areas will see up to two inches of rain, however, we could see isolated amounts even higher if storms linger or train over the same areas for longer periods of time.

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 ArkLaTex region, according to the Weather Prediction Center.