Here’s a comprehensive look at the weather forecast for Monday across the nation.

A quasi-stationary front stretching from the Southeast along the Gulf Coast to the Southern Plains will persist through Wednesday, triggering showers and thunderstorms. Heavy rain is expected, leading the Weather Prediction Center (WPC) to issue a Slight Risk (level 2/4) of excessive rainfall over parts of the Southeast until Tuesday morning. This heavy rain poses a risk of localized flash flooding, particularly in urban areas, roads, small streams, and low-lying areas.

In the Northern and Central High Plains, upper-level energy and ample moisture will fuel showers and severe thunderstorms. The Storm Prediction Center (SPC) has issued a Slight Risk (level 2/5) of severe thunderstorms for this region through Tuesday morning. Expect frequent lightning, severe thunderstorm wind gusts, hail, and the possibility of tornadoes, with a heightened risk of hail reaching two inches or greater.

The Pacific Northwest, Northern Intermountain Region, and Southern Plains will also experience showers and thunderstorms from late afternoon into the evening. Additionally, the Ohio Valley will see developing showers and thunderstorms.

On Tuesday, tropical moisture combined with a lingering boundary will bring showers and thunderstorms with heavy rain to the Southeast and southern Mid-Atlantic. The WPC has issued a Slight Risk (level 2/4) of excessive rainfall for these areas from Tuesday through Wednesday morning, with similar flash flood risks.

A strong upper-level impulse will generate showers and severe thunderstorms over the Northern Plains on Tuesday. The SPC has issued a Slight Risk (level 2/5) of severe thunderstorms, with hazards including frequent lightning, severe thunderstorm wind gusts, hail, and a minimal tornado threat.

Showers and thunderstorms are also expected from the Upper Mississippi Valley/Great Lakes southward to the Gulf Coast and parts of the Northeast. Meanwhile, smoke from Canadian wildfires has triggered Air Quality Alerts over the Upper Great Lakes, Upper Mississippi Valley, and the Northeast.

An intensifying upper-level high over the Southwest will cause temperatures to rise across the Desert Southwest, potentially reaching the mid-110s by Tuesday. Central and southern Arizona are expected to face the most significant heat, with widespread Major to Extreme Heat Risk extending into southern California. Extreme Heat Watches and Warnings are in effect for parts of Southeastern California and the Southwest. Residents are advised to limit outdoor activity, stay hydrated, and seek air-conditioned environments. More safety information can be found at www.weather.gov/safety/heat.