In a year that has already seen more than 300 tornadoes and 31 deaths, deadly and dangerous tornadoes like the ones that tore through Arkansas and Illinois on Friday are forecast to continue on Tuesday and again the following weekend.

In fact, with 313 tornadoes so far, according to Storm Prediction Center data, it was the third-most-active start to a year on record in the U.S., even before Friday’s violent weather. Last week’s devastating outbreak in the South, which killed more than 20 people in Mississippi and Alabama, followed several previous outbreaks.

“We should be at about 200 tornadoes for today’s date,” Victor Gensini, associate professor at Northern Illinois University, told USA TODAY on March 30. “So we’re running about 100 tornadoes above average, and we have been the entire year.” 

Tornado warning:Twisters hitting more frequently and dealing more deaths in the South

Tornado activity is expanding:Southern states see more twisters than ever

What happened Friday?

A low pressure system moving in from the west, with warm dry air behind it and warm, humid air flowing northward to the east from the Gulf of Mexico created a classic set up for severe storms and tornadoes. 

Severe storms began forming by late morning, forcing the National Weather Service to issue its first “high risk” warning of the year. 

At least three tornadoes were confirmed by mid-afternoon, in addition to damaging high winds and huge hail. Meanwhile, blizzard conditions were reported in South Dakota.

What’s the forecast for Tuesday?

A similar pattern is expected to set up Tuesday, amplified by greater heat and humidity, increasing the risk for severe weather, Gensini said.

If you wanted to draw a textbook severe weather configuration, “this would certainly be it,” he said. Between dry conditions to the west, and hot, wet conditions to the east, he expects to see a “pretty broad area of real estate” at risk on Tuesday afternoon and evening.

A “powerhouse jet stream” moving in from the Plains was moving Friday’s storms at highway speeds, and a similar effect is expected Tuesday. Those kinds of high winds tend to increase the risk for twisters that stay on the ground for a long time, such as the March 24 tornado that devastated Rolling Fork, Mississippi.