Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 AM EDT Wed Oct 06 2021 Valid 12Z Wed Oct 06 2021 - 12Z Fri Oct 08 2021 ...There is a Moderate Risk of excessive rainfall over parts of the Central Gulf Coast and the Southern Appalachian/Tennessee Valley through Thursday morning... ...Air Quality Alerts over the San Joaquin Valley through Wednesday... ...Temperatures will be 10 to 30 degrees above average over parts of the Northern/Central High Plains into the Upper Mississippi Valley; there is a Critical Risk of Fire Weather over the Northern High Plains... An upper-level low over Lower Mississippi Valley will slowly move northward movement to the Great Lakes by Friday. The circulation around the upper-level low will stream moisture northward over the Central Gulf Coast to the Southeast, extending into roughly the Ohio Valley/Great Lakes on Thursday and into the Mid-Atlantic by Friday. The moisture will aid in producing showers and thunderstorms over the Central Gulf Coast/Southeast into the Ohio Valley/Mid-Atlantic, producing heavy rain through Friday. Therefore, the WPC has issued a Moderate Risk of excessive rainfall over parts of the Central Gulf Coast and the Southern Appalachian/Tennessee Valley through Thursday morning. The associated heavy rain will create numerous areas of flash flooding. Furthermore, many streams may flood, potentially affecting larger rivers through Thursday morning. The threat of excessive rainfall will lessen on Thursday into Friday to a Slight Risk over the Southern Appalachians/Tennessee. In addition, on Thursday, showers and thunderstorms will extend into parts of the Great Lakes/Upper Mississippi Valley. In the meantime, showers and thunderstorms over parts of the Central/Southern Rockies into parts of the Great Basin/Southwest will slowly end by tonight. Meanwhile, a front extending from the Northern Rockies southwestward to Central California will slowly move eastward to the Northern Plains to the Great Basin by Friday. Weak onshore flow will help produce rain over parts of the Pacific Northwest/Northern California, slowly taper off from south to north by Thursday morning. Scattered showers and thunderstorms will develop along and near the boundary over parts of the Great Basin into the Northern Rockies starting by tonight. Furthermore, the smoke from wildfires will lead to poor air quality over the San Joaquin Valley of California, where Air Quality Alerts are in effect through today. Additionally, an upper-level ridge will develop over parts of the Upper Midwest as temperatures will become 10 to 30 degrees above average over parts of the Northern/Central High Plains into the Upper Mississippi Valley. The above-average temperatures, lowering relative humidity, and gusty wind lead to a Critical Risk of Fire Weather over the Northern High Plains. Consequently, Red Flag Warnings are over parts of the Northern High Plains. Ziegenfelder Graphics are available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php