Scattered showers and thunderstorms will move through the Midwest on Sunday as a cold front treks eastward from the Plains.
A low pressure system over central Canada will continue moving into eastern Canada. The system will create a cold front that will extend southward from this system, moving through the upper and mid-Mississippi River valleys, and up the Ohio River valley. This system will pull moisture in from the Gulf of Mexico, kicking up widespread showers and thunderstorms throughout the day. Rainfall totals will range from 0.5 to 1.0 inches, with up to 2 inches likely in areas of thunderstorm development.
At the same time, another low pressure system will be developing behind this system as a trough moves off the Northern Rockies and into the Northern High Plains. This will produce scattered storms across the Dakotas. There is a slight chance of severe weather development in the afternoon and evening hours as this system moves from the Dakotas and into western Minnesota. Main threats will be large hail, damaging wind gusts, and possibly a few tornadoes. Onshore flow from the Pacific Ocean behind this system will allow for widespread rain showers to develop across parts of Washington, Idaho and Montana.
In the South, onshore flow from the Gulf of Mexico will support shower and thunderstorm activity across the Gulf Coast. Isolated thunderstorms may become severe with large hail and strong winds. Meanwhile, fire danger remains extremely high across the Southwest as a ridge of high pressure covers the Great Basin, southern California, and into western Texas.
High temperatures will reach into the lower 100s in some areas, coupled with low humidity and breezy conditions.
Temperatures in the Lower 48 states ranged Saturday from a morning low of 28 degrees at Yellowstone, Wyo., to a high of 102 degrees at Glendale, Ariz.
Weather Underground: http://www.wunderground.com
National Weather Service: http://iwin.nws.noaa.gov