A tornado touches down south of McLean, Tex., on May 16. (Mark Smith/European Pressphoto Agency)

The Southern Plains faces a dangerous situation Thursday as the National Weather Service’s Storm Prediction Center (SPC) in Norman, Okla., is forecasting a serious severe weather outbreak.

Thunderstorms are expected to produce tornadoes, SPC said Thursday morning, some of which may be intense and remain on the ground for a long time.

SPC placed north central Oklahoma and south central Kansas in its “high-risk” zone for severe storms, including Wichita and Dodge City. Such high-risk declarations are rare and reserved for the most threatening severe weather situations.

Severe weather risk map from National Weather Service Storm Prediction Center.

In addition to their tornado potential, storms are expected to generate giant hail to the size of softballs and damaging straight-line winds.

The risk of such severe weather hazards aren’t confined to the high risk zone.

Dangerous storms may also erupt in the surrounding zones of risk, ranging from slight to moderate, and include the population centers of Dallas, Oklahoma City and Kansas City.

National Weather Service Storm Prediction Center risk categories.

The severe weather will be triggered by an intense atmospheric disturbance in the Southwest United States punching out into the Plains, where the atmosphere is becoming extremely unstable.

“The atmosphere is highly conducive for maintaining storm intensity,” said Patrick Marsh, warning coordination meteorologist at SPC.

In the rare instances SPC issues high-risk outlooks each year (on average), they frequently (but not always) portend devastating tornado outbreaks.

From 2010 to 2016, the website U. S. Tornadoes reports, the average high-risk event produced 62 tornadoes, 16 of which were strong, and 31 fatalities. But a few of these events failed to produce strong tornadoes and resulted in no deaths.

Officials urged residents living in zones of elevated storm risk Thursday to have a plan of action. “Figure out what you want to do if a tornado is spotted in your area now, don’t wait to figure it out once it has been spotted,”  Marsh said. “It’s easier to think clearly when you’re not in the stress of the moment”

Mike Smith, senior vice president at AccuWeather Enterprise Solutions, advised taking the following precautions:

  • Consider taking family heirlooms to your shelter now.
  • Consider postponing little league games.
  • Making plans now for sheltering any infirm friends or relatives.
  • Put your car in the garage or under the car port due to the risk of giant hail (see below).
  • Secure items that can be blown about.
  • Wouldn’t hurt for you to get some extra cash from the ATM and fill your fuel tank.
  • Plan to take any prescription drugs to your shelter.
  • Wear shoes to shelter in case the worst happens.
  • If you don’t have underground shelter, make sure there is room in an interior bathroom or closest in the middle of the house for your family.

Smith also recommended downloading a weather app, such as AccuWeather’s, to receive the most timely storm warnings.

The atmospheric setup supporting this potential severe weather outbreak features textbook ingredients. “The prognosticated ingredient/parameter space is ideal for a multi-hazard severe-weather outbreak,” SPC wrote in its morning technical discussion.

The storms are expected to form in a transition zone between an usually heavy snowstorm so late in the season in the Rockies and record heat in the eastern third of the country.

Levels of instability are forecast to rise to extreme levels, resulting in powerful storm updrafts, which are areas of vigorously rising air. These updrafts may begin to rotate from intersecting air streams moving at different speeds — forming tornadoes.

SPC cautions that even with these classic ingredients for tornadoes in place, uncertainties remain with respect to the exact timing of storms and how concentrated and intense they will become.

“There is a potential failure mode. If the storms go up too quickly, we may not realize the full potential of the atmosphere,” Marsh said. “That would be a good thing for people.”

Thursday is just the first of two potentially threatening days of severe weather, Marsh stressed. On Friday, elevated severe storm risk zones spanned from central Texas to central Illinois. “This is just day one,” he said. “There is the potential for severe storms tomorrow [Friday] and the risk lines up with population centers.”

This week has been a very busy one for severe weather. On Tuesday, two people died in tornadoes in Wisconsin and Oklahoma.

On Wednesday, SPC logged more than 300 reports of severe weather, mostly from damaging straight-line winds in Iowa, northern Illinois and Wisconsin.