Millions will be under the threat of severe weather this weekend as a battle between winter and spring will take place on the Plains.
A clash between warm and cold air, not uncommon for the month of March, will create the conditions needed for thunderstorms to turn severe through the weekend and even into the beginning of next week.
The same storm system that is forecast to dump feet of snow over portions of the Rocky Mountains this weekend will also set the stage for severe weather in the central and southern Plains.
"As the storm pivots eastward, it will draw warm, moist air northward from the Gulf of Mexico. At the same time, dry and cooler air from the desert Southwest will shift eastward," AccuWeather Senior Meteorologist Alex Sosnowski said.
These opposite air masses colliding together will provide the necessary fuel for widespread thunderstorm development. When adding in very strong winds high up in the atmosphere, that provides a recipe for potent thunderstorms that can turn damaging.
The threat of stronger thunderstorms began on Friday as the storm system that had been slowly crawling over the Southwest and the Rocky Mountains began to emerge over the Plains. Scattered thunderstorms began to develop Friday afternoon across southern Kansas, Oklahoma, and into the Texas Panhandle.
Severe thunderstorm warnings were first issued in Texas Friday afternoon, along with a few tornado warnings.
Around 5 p.m. CST, a possible tornado was spotted near Abernathy, Texas, a city that straddles Hale and Lubbock counties. The sighting was reflected in a preliminary tornado report from the National Weather Service's Storm Prediction Center.
A second possible tornado was reported in Crosby, Texas, around 6 p.m. local time. In Hale County, Texas, hail up to 2.5 inches in diameter was reported around the same time.
AccuWeather On-Air Meteorologist Brittany Boyer warned that a moderate risk for strong wind and hail with a slight risk for flooding and tornadoes will continue into early Saturday morning.
However, forecasters say a much broader and more populous area could be at risk for dangerous weather on Saturday and Sunday, with over 20 million Americans in the threat zone, including the bigger cities of Oklahoma City, Dallas, and Little Rock, Arkansas.
People in these cities and surrounding communities should begin thinking ahead about possible disruptions to travel or outdoor plans during the weekend, as well as preparations that can be made in advance of any severe weather. This includes securing loose items outdoors and enabling severe weather alerts on mobile devices.
During Saturday, a new round of hard-hitting storms is likely to develop in West Texas and then sweep eastward through the remainder of the weekend, when they are forecast to reach the lower Mississippi Valley later Sunday.
For the first half of the weekend, storms are likely to fire up in northwestern Texas around midday on Saturday and continue to push eastward through northern Texas and the western half of Oklahoma.
"At this time, all facets of severe weather are possible, ranging from flash flooding and hail to strong straight-line wind gusts and even a few tornadoes," AccuWeather Chief On-Air Meteorologist Bernie Rayno said.
The threat for tornadoes, at this time, looks to be higher on Saturday and Saturday night as the line of thunderstorms first develops.
"While a major tornado outbreak does not appear likely at this time, as we have seen with isolated incidents this past winter in the Southeast states, all it takes is one lone storm to pose great risk to lives and property," Sosnowski said.
A tornado tore through a Birmingham, Alabama, suburb during the night of Jan. 25-26, killing one person and injuring several others. A few weeks later, a single tornado struck in eastern North Carolina and took the lives of three people.
On Sunday, the threat of severe weather is likely to shift eastward to include areas from eastern Oklahoma and Texas all the way to the Mississippi River. The main severe weather threats on Sunday are likely to be heavy, drenching downpours and damaging winds.
"Powerful wind gusts in lieu of tornadoes and large hail can inflict a great deal of damage in some cases," Sosnowski said.
Travel along stretches of interstates 20, 30, 35, and 40 could be severely impeded at times as the storms sweep through, with drivers likely to experience sudden reductions in visibility and ponding of water on the roadways. Downed trees and power lines could block secondary roadways, and some communities could be left without power in the wake of the storms.
Farther north of the severe weather threats, even more heavy rainfall is expected from this slow-moving storm.
Persistent rounds of rain will continue across the central and southern Plains through the end of the week and the weekend. From eastern Kansas through southern Missouri, it is possible that more than 4 inches of rain could fall across the region in just a few days.
An AccuWeather Local StormMax™ of 11 inches is possible in this corridor should persistent downpours impact the same community.
With some rivers already running above flood stage in this corridor, the additional runoff could prolong the time it takes for water levels to recede and perhaps trigger new river flooding elsewhere.
Even in the absence of river flooding, motorists across portions of interstates 35, 44, and 70 could experience slowdowns due to the downpours.
Drier air that sweeps in behind the storm by early next week will promote much calmer weather in the immediate wake of the storms for any necessary cleanup operations that may need to take place. However, the risk for heavy, gusty, and even isolated severe storms can shift east into the Ohio and Tennessee valleys on Monday.