Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 426 PM EDT Sat Jul 24 2021 Valid 00Z Sun Jul 25 2021 - 00Z Tue Jul 27 2021 ...Main monsoon activity to continue over the Desert Southwest through Monday... ...Severe weather possible today over the Great Lakes... ...Hot and humid weather over the Plains and Southeast today; Excessive Heat continues over Southeast Montana through Tuesday ... The active monsoon pattern persists over the Desert Southwest and Great Basin, with widespread showers and thunderstorms evident on satellite and RADAR imagery this afternoon ahead of a west moving upper disturbance. Many locations across the Southwest are vulnerable to additional heavy rain (particularly burn scar areas), with many areas having received well above normal precipitation over the past week. A Moderate Risk of Excessive Rainfall remains in effect through tomorrow morning over West-Central Arizona and Southwest New Mexico, where areal rainfall averages of 1-2+ inches and local amounts exceeding 4 inches are possible. More showers and thunderstorms are likely through late Sunday-Monday before the activity drops off, as the main monsoon moisture moves slowly north and the aforementioned disturbance slides to the west. A Slight Risk of Excessive Rainfall accordingly extends from Central Arizona into South Utah/Nevada beginning tomorrow morning through Monday. Flash Flood Watches that cover much of Arizona, West New Mexico, and Southwest Colorado are currently set to expire Sunday night. Over the Midwest, a cold front analyzed across the Northern Plains is forecast to extend southeast over the Northern Ohio Valley/Midwest by tonight. Ahead of the front, thunderstorm development is just underway, and a Severe Thunderstorm Watch is in effect over Central Michigan. A Slight Risk of severe thunderstorms today runs over much of Michigan to west of the Chicago Metro, with primary threats including damaging winds and isolated tornadoes. On the periphery of the storm activity, hot and humid conditions are the foremost concern; Heat Advisories dot the Plains through tomorrow as heat indices of 105-110 are expected. The urban heat effect will likely worsen conditions, and the Kansas City Metro remains under an Excessive Heat Warning until Wednesday evening. A separate Heat Advisory also remains over the Southeast including portions of Louisiana and Mississippi through today with heat indices approaching 112. Meanwhile, Southeast Montana is under an Excessive Heat Watch through Tuesday, with dangerous triple digit highs approaching 110 possible. In addition to the heat, air quality remains a serious concern in the region as smoke from wildfires blows downstream; Air Quality Alerts remain over portions of southern Montana and western Wyoming. East of Florida, the National Hurricane Center continues to monitor the potential for tropical storm formation with an area of disturbed weather. Conditions are noted to be marginally conducive for marginal development, but development is possible as the disturbance moves west toward land. An Air Force Reserve Hurricane Hunter is en route to investigate the disturbance. Users are encouraged to monitor the National Hurricane Center for the latest forecast information with this disturbance. Asherman Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php