Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Sat May 08 2021 Valid 00Z Sun May 09 2021 - 00Z Tue May 11 2021 ...Severe weather and moderate to heavy rainfall potentially causing flash flooding are forecast across portions of the Plains and Mississippi and Ohio Valleys... ...Late-season snowfall across the Northern Rockies to Northern High Plains... ...Colder than average temperatures are likely in the northern U.S., while warm and dry conditions will cause Critical Risks of fire weather in California and New Mexico... A storm over the Central Plains will move eastward, moving off the Northeast Coast with a trailing front extending across the southern Mid-Atlantic, Southeast, Central Gulf Coast, and the Southern Plains by Monday. The system will produce showers and thunderstorms over parts of the Central/Southern Plains and the Middle Mississippi Valley on Saturday evening into Sunday. The SPC has issued an Enhanced Risk of severe thunderstorms over parts of the Lower Missouri Valley through Saturday evening. The hazards associated with these severe thunderstorms are frequent lightning, severe thunderstorm wind gust, hail, and a few tornadoes. Some of the storms will have a 10% or greater probability of producing hail two inches or greater over parts of Kansas through Saturday evening. The thunderstorms will also produce heavy rain. The WPC has issued a Slight risk of excessive rainfall over parts of the Central Plains and the Lower Missouri Valley through Sunday morning. The hazards associated with the rain are scattered flash flooding, where urban areas, roads, and small streams are the most vulnerable. On Sunday, the severe thunderstorms and heavy rain will move southeastward to parts of the Southern Plains, Lower Mississippi Valley, and the Tennessee Valley. The SPC has issued a Slight Risk of severe thunderstorms over parts of the Southern Plains and Lower Mississippi/ Tennessee Valleys. The main hazards associated with these severe thunderstorms are frequent lightning, severe thunderstorm wind gust, hail, and a few tornadoes. Some of the storms will have a 10% or greater probability of producing hail two inches or greater over parts of the Southern Plains and Lower Mississippi Valley. Similarly, the SPC has issued a Slight risk of excessive rainfall over parts of the Lower Mississippi and Tennessee Valleys. The hazards associated with the rain are scattered flash flooding, where urban areas, roads, and small streams are the most vulnerable. Furthermore, the rain will move into the Ohio Valley overnight Saturday, moving into parts of the Northeast on Sunday. The rain will continue over parts of the Northeast on Monday, while showers and thunderstorms move into parts of the Mid-Atlantic through Monday evening. Meanwhile, snow and lower-elevation rain will develop over the Northern/Central Rockies underneath an upper-level low from Saturday into Monday evening. Additionally, late-season snow is possible in the Northern High Plains on Saturday evening into Monday afternoon. Temperatures under broad upper-level troughing will be well below average from across the northern tier states to much of the eastern U.S. today before a warm-up in the Southeast to Carolinas on Sunday. Freeze Warnings and Frost Advisories are in effect for parts of the Upper Great Lakes region into parts of the Northeast. However, temperatures will be warmer across the south-central U.S. A front will push the heat southward on Sunday, with temperatures in the 100s for South Texas. Warm and dry conditions in the Southwest/Southern High Plains and interior Northern California have prompted Elevated to Critical Risks of fire weather and Red Flag Warnings in those areas. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php