Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 302 AM EDT Sun Sep 03 2023 Valid 12Z Sun Sep 03 2023 - 12Z Tue Sep 05 2023 ...There is a Slight Risk of excessive rainfall over the parts of the Great Basin/Northern Intermountain Region on Sunday and Northern Rockies on Monday... ...There are Heat Advisories over parts of the Northern/Central Plains and Upper Mississippi Valley on Sunday... ...Upper-level ridging will build over the Great Lakes/Ohio Valley... An upper-level low over Northern California and the Pacific Northwest will weaken and move eastward to the Northern High Plains by Tuesday. Energy associated with the upper-level low will move over parts of the Great Basin/Northern Intermountain Region, producing showers and thunderstorms with heavy rain. Therefore, the WPC has issued a Slight Risk of excessive rainfall with these thunderstorms over parts of the Great Basin/Northern Intermountain Region through Monday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, narrow crayons/gullies, and burn scars the most vulnerable. On Monday, as the energy continues to move eastward, showers and thunderstorms with heavy rain will develop over parts of northeastern Idaho, southern Montana, and northern Wyoming. Therefore, the WPC has issued a Slight Risk of excessive rainfall with these thunderstorms over parts of the Northern Rockies/Northern High Plains from Monday into Tuesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, narrow crayons/gullies, and burn scars the most vulnerable. Meanwhile, upper-level ridging over the Northern/Central Plains and Upper Mississippi Valley will promote hot temperatures over the region, prompting Heat Advisories on Sunday. On Monday, the upper-level ridging will move over the Great Lakes and Ohio Valley, allowing hot temperatures to move over the area and parts of the Mid-Atlantic. Furthermore, upper-level energy over the Southern Plains will aid in creating showers and thunderstorms over parts of the Lower Mississippi Valley and eastern Texas on Sunday and Monday. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php