National Weather Service United States Department of Commerce

Thunderstorms and Heavy Rainfall in the Plains; Hazardous Heat in the South and Southeast

Severe thunderstorms will be possible across the northern/central Plains through Tuesday afternoon and from the central Plains to the Mid-Mississippi Valley Tuesday evening through Wednesday morning. Storms may produce large hail and damaging wind gusts, and heavy rainfall may lead to scattered instances of flash flooding. Meanwhile, hazardous heat persists across the South and Southeast. Read More >

All three of the following criteria must be exceeded in order for Red Flag Warning conditions to be met:

  • Sustained 20 ft Winds: >15 mph
  • Relative Humidity: < 25%
  • 10 hr Dead Fuel Moisture: <9%

Below is a matrix that describes the Elevated Fire Danger criteria:

Elevated fire danger matrix for the St. Louis forecast area.