Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 355 PM EDT Sun May 18 2025 Valid 00Z Mon May 19 2025 - 00Z Wed May 21 2025 ...There is a Slight Risk of excessive rainfall over parts of the Central/Southern Plains, Middle/Lower Mississippi Valley, and the Ohio Valley on Sunday and Monday and from the Upper Mississippi Valley to the Ohio Valley... ...There is a Moderate Risk of severe thunderstorms over parts of the Central/Southern Plains on Sunday; there is an Enhanced Risk of severe thunderstorms over parts of the Central/Southern Plains and Middle /Lower Mississippi Valley on Monday and Tennessee and Lower Mississippi Valleys on Tuesday... ...There is a Critical Risk of fire weather over the Southern Rockies/Southern High Plains on Sunday and Monday... A front extending from the Northern/Central Rockies eastward to the Central Plains, Lower Mississippi Valley, and the Southeast will move eastward to the Middle Mississippi/Ohio Valleys and Lower Mississippi Valley by Tuesday. The boundary will produce showers and severe thunderstorms with an increased threat of EF2 to EF5 tornadoes and hail, two inches or greater over parts of the Central/Southern Plains. Therefore, the SPC has issued a Moderate Risk (level 4/5) of severe thunderstorms over parts of the Central/Southern Plains through Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Additionally, the showers and thunderstorms will create heavy rain over parts of the Central/Southern Plains. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Central/Southern Plains through Monday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, low-lying areas the most vulnerable, and landslides on roads. Moreover, a second area of showers and severe thunderstorms will develop over parts of the Tennessee Valley and the Southeast. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over the Tennessee Valley and Southeast through Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a minimal threat of tornadoes. Furthermore, the upper-level energy associated with the front will produce rain and highest-elevation snow over parts of the Northwest to the Northern/Central Rockies, with showers and thunderstorms over parts of the Northern/Central Plains through Monday morning. For Monday, rain and highest-elevation snow will continue over the Central Rockies, with showers and thunderstorms over the Northern/Central Plains. In addition, on Monday, as the front advances eastward, showers and severe thunderstorms with EF2 to EF5 tornadoes and hail, two inches or greater over parts of the Central/Southern Plains. Therefore, the SPC has issued an Enhanced Risk (level 3/5) of severe thunderstorms over parts of the Central/Southern Plains from Monday into Tuesday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Additionally, the showers and thunderstorms will create heavy rain over parts of the Central/Southern Plains and Middle/Lower Mississippi Valley. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Central/Southern Plains and Middle/Lower Mississippi Valley from Monday into Tuesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, low-lying areas the most vulnerable, and landslides on roads. Moreover, on Monday, a second area of showers and severe thunderstorms will develop slightly farther east over parts of the Tennessee Valley, Southern Appalachians, and Southeast. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over the Tennessee Valley, Southern Appalachians, and Southeast from Monday through Tuesday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a minimal threat of tornadoes. On Tuesday, rain and wet snow will develop over parts of the Northern Plains as upper-level energy moves east over the region. Likewise, as the front moves east on Tuesday, showers and severe thunderstorms will develop over parts of the Middle/Lower Mississippi Valley and the Ohio/Tennessee Valleys. Therefore, the SPC has issued an Enhanced Risk (level 3/5) of severe thunderstorms over the Tennessee/ Lower Mississippi Valleys on Tuesday. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Similarly, the showers and thunderstorms will create heavy rain over parts of the Upper/Middle Mississippi Valley, Ohio Valley, and the Central Appalachians. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Upper/Middle Mississippi Valley, Ohio Valley, and the Central Appalachians on Tuesday. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, low-lying areas the most vulnerable, and landslides on roads. Meanwhile, on Monday, a third front will move onshore over the Pacific Northwest and inland to the Northern Rockies/Great Basin by Tuesday evening. The boundary will produce rain and highest elevation snow over the Northwest and the Northern Intermountain Region, continuing into Tuesday evening. Elsewhere, deep boundary-layer mixing behind a sharpening dryline and a deepening surface low and associated gradient wind response will be responsible for widespread Critical fire-weather conditions. The combination of dry air, dry fuels, and gusty winds over the Southern Rockies prompted a Critical Risk of fire weather over the region on Sunday and Monday. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php