Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 340 PM EDT Wed Oct 21 2015 Valid 00Z Thu Oct 22 2015 - 00Z Sat Oct 24 2015 ...Flash flooding possible through Friday for portions of the Southern Plains... ...Severe thunderstorms possible today across portions of the Southwest and southern plains... The overall flow pattern over the continental U.S. will be fairly active as multiple systems develop, morph and diminish over the next few days. The upper-level low over the Southwest continues to propagate toward the East. With a nearly stationary boundary near the Four Corners region and ample low-level moisture east of the Rockies, a vast area of scattered to widespread convection has developed. Anomalous pools of moisture are forecast for the region through the end of the week, which will help increase the likelihood of heavy rain and/or intense rainfall rates through Thursday. Rain amounts are forecast to range from 2 to 6 inches across portions of the Southern Plains. Isolated areas may see amounts exceed 6 inches. Temperatures will likely be conducive for snow for elevations greater than 10,000ft in Colorado -- with 1 to 4 inches of accumulation possible. The threat of flash flooding will remain possible through Friday. Additionally, the Storm Prediction Center is forecasting a risk of severe thunderstorms across portions of the Southwest and Southern Plains through Thursday morning. The Northern and Central Plains will have a progressive low pressure system track through reaching Nova Scotia and Newfoundland by Friday. The Low over the Southwest will lift northward and absorb into the flow over the Central Plains. Showers and a few thunderstorms will be possible in association with this system across the Great Lakes and Northeast into Thursday. Northern Maine may have a mix of rain, snow, sleet, or freezing rain this evening through the early morning hours of Thursday. Accumulations, if any, will remain light. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php