Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 311 PM EDT Sat Jun 19 2021 Valid 00Z Sun Jun 20 2021 - 00Z Tue Jun 22 2021 ...The threat of flash flooding and isolated tornadoes associated with Tropical Storm Claudette will continue across portions of the Southeast tonight and into the Carolinas on Sunday... ...Heavy rain and severe thunderstorms possible across parts of the Ohio Valley and Midwest through the end of the weekend... ...Dangerous and record-breaking heat continues across California and the Southwest, while expanding into the Pacific Northwest on Sunday... The center of Tropical Storm Claudette is currently pushing northeast into southwestern Alabama and is expected to become a tropical depression by tonight. Much of the hazardous weather associated with Claudette is occurring on the northern and eastern peripheries of the storm. Additional rainfall totals of 3 to 6 inches with isolated maximum amounts of 8 inches are expected across eastern Alabama, northern Georgia, and the Florida Panhandle. This amount of rain will likely lead to flash flooding where continuous downpours occur. WPC has issued a Moderate Risk (level 3/4) of Excessive Rainfall throughout portions of the Southeast and into the Southern Appalachians. Storm total rainfall amounts could reach as high as 15 inches in southeast Louisiana, southern Mississippi, southern Alabama, and the western Florida Panhandle. Additionally, thunderstorms capable of producing brief tornadoes will remain a concern into this evening for southeast Alabama, southwest Georgia, and the Florida Panhandle. By Sunday the center of Claudette is expected to cross through central Georgia and into the eastern Carolinas on Monday, producing a few inches of additional rainfall here. Some restrengthening is possible and Claudette could regain tropical storm strength on Monday as it exits off the North Carolina coastline. Tropical Storm Watches have been issued for coastal North Carolina. Farther north, a quasi-stationary boundary and a strengthening low pressure system exiting the northern High Plains will produce additional rounds of showers and thunderstorms from the Northeast to the central Plains this weekend. Severe thunderstorms are most likely this evening between the Mid-Atlantic and Ohio Valley, as well as a large region from the central Plains to the Middle Mississippi Valley. The biggest threat with these storms will be associated with damaging wind gusts and large hail. Flash flooding is also a concern in the Ohio and Middle Mississippi valleys, where heavy rain already occurred earlier this morning. On Sunday, the advancing low pressure system is forecast to reach the Upper Midwest. A warm front is then expected to lift north into the Great Lakes and produce ripe conditions for severe weather over the Midwest and Lower Michigan. The Storm Prediction Center has issued an Enhanced Risk (level 3/5) of severe thunderstorms on Sunday that stretches from southeast Iowa to northern Indiana and southwest Lower Michigan. Damaging wind gusts are the greatest concern here, but large hail and isolated tornadoes are also possible. A trailing and rather potent cold front is expected to swing into the southern Plains and eastern U.S. by Monday, which will shift severe weather and thunderstorm chances eastward. The western U.S. is also dealing with potentially dangerous weather, but heat and fire weather remains the culprit. A long-duration heat wave has gripped the southwest corner of the country and is expected to continue through this evening and Sunday. Above average temperatures are forecast throughout California, the Intermountain West, and Southwest through the rest of today before expanding into the Pacific Northwest on Sunday and Monday. A few daily record high temperatures could fall throughout these regions this weekend, with cooler temperatures projected to return to the Southwest on Monday. Excessive Heat Warnings and Heat Advisories remain in effect throughout much of the Southwest, California, and the central Great Basin. The combination of record heat and exceptional drought is also leading fire weather concerns throughout the northern High Plains and central/southern Rockies. Red Flag Warnings are in effect across parts of eastern Montana, Wyoming, southeast Idaho, Utah, and western Colorado. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php