Thunderstorms will persist around the Central U.S. on Sunday as a low pressure system over the Plains combines with a low pressure trough moving off the northern Rocky Mountains. These systems will draw warm, moist air in from the Gulf of Mexico and produce a warm front stretching eastward from the upper Midwest through the Ohio River Valley.
The flow behind this elongated low pressure system will create a cold front that stretches southward, moving through the Central and Southern Plains during the day. Warm, moist air ahead of this cold front will also allow for showers and thunderstorms to develop. These storms are expected to turn severe from the Great Lakes through the mid-Mississippi River Valley and into the Southern Plains. In areas of severe weather development, expect large hail, damaging winds, and a few tornadoes.
Ahead of this system in the East, high pressure over the Southeastern states will be shoved eastward by the approaching low pressure system. This will create onshore flow from the Gulf of Mexico, bringing widespread showers and thunderstorms to the Southeast and mid-Atlantic states.
In the West, a high pressure ridge continues building over the Western U.S. This will allow for another warm, dry, and sunny day across the region and heighten the prospect of fire danger for most of the Western U.S.
Temperatures in the lower 48 states ranged Saturday from a morning low of 19 degrees at Truckee, Calif., to a high of 100 degrees at Vernon, Texas.
Weather Underground: http://www.wunderground.com
National Weather Service: http://iwin.nws.noaa.gov