Weather across America

(NATIONAL) Severe thunderstorms and heavy rainfall expected from the Southern Plains to the Southeast, Excessive Heat Warnings and Heat Advisories across the Southern Plains and western/central Gulf Coast, and a Critical Fire Weather Risk over portions of the Southwest and Southern Plains.

The pattern over the lower 48 will amplify significantly over the next couple of days. This will promote dangerous heat, fires, heavy rainfall and severe weather across the southern tier of the country. Severe thunderstorms are expected from the Ark-La-Tex to the central Gulf Coast states Sunday, as damaging wind gusts and large hail threaten these areas. 

Heavy rainfall and a very unstable atmosphere will also favor a flash flooding threat across the Middle/Lower Mississippi Valley, where 2-4 inches of rain may focus around a pair of quasi-stationary fronts. Showers and thunderstorms will shift into the Ohio/Tennessee Valleys and Southeast/Mid-Atlantic on Juneteenth where 1-3 inches of rainfall are possible over the Appalachian Mountains of the Carolinas as well as the Florida Panhandle. 

Severe Thunderstorms are possible over the central/Florida Gulf Coast on Monday as well where damaging gusts are possible. Elsewhere, the Mexican ridge will expand northward into the central CONUS over the next couple of days. This will result in the continuation of anomalously warm temperatures over southern Texas and the western/central Gulf Coast. 

Temperatures in the 100s will not only rival daily high temperature marks for the nation, but may tie or brake existing records. There will be little relief overnight with lows in the upper 70s and 80s, which is why there are Excessive Heat Warnings and Heat Advisories in place across the western and central Gulf Coast. 

Continued warm, dry and windy conditions will support a Critical Fire Weather Risk area over southern Arizona and much of New Mexico. The deepening western trough, will introduce cooler than average temperatures to much of the West through early this week. High temperatures are expected to be between 10-20 degrees below average on Monday and Tuesday. 

Rainy/cloudy conditions will promote cooler daytime highs across the southeastern quadrant of the country over the next couple of days. Canadian wildfire smoke is likely to continue impacting the eastern half of the country over the coming days despite being far less dense than what the Northeast and Mid-Atlantic experienced a couple of weeks ago.