Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 345 PM EDT Tue Sep 10 2019 Valid 00Z Wed Sep 11 2019 - 00Z Fri Sep 13 2019 ...Threats for severe thunderstorms and flash flooding from the Upper Midwest westward into portions of the central and northern Great Plains through Thursday... ...Potential for record breaking heat near the southern Appalachians Wednesday and Thursday... ...Significantly colder than average for portions of the northern Rockies into the northern High Plains along with accumulating snow across the highest elevations of northwestern Wyoming... A slow moving front stretching westward through the central Plains will be a focus for severe thunderstorm development later this afternoon. Storm coverage is expected to increase across western South Dakota and northern Nebraska and spread eastward toward the Minnesota/Iowa border overnight. Threats for tornadoes, large hail, damaging winds and flash flooding will all be present. An upper level system will move eastward through the Great Basin early Wednesday with anomalously cold air filling in behind an advancing cold front in the central to northern Plains. Moderate to heavy precipitation is expected with this system across Wyoming and eastern Montana. Temperatures will drop early Wednesday changing rain to snow into the higher elevations of northwestern Wyoming and southern Montana (at and above 9,500 feet above sea level), where 2-4 inches of snowfall accumulation can be expected, higher as one moves up in elevation. Meanwhile, another round of severe thunderstorms and heavy rain is expected across portions of the central to northern Plains later on Wednesday into early Thursday morning. Through Thursday evening, 2-day rainfall totals of 2-4 inches are likely for portions of eastern Montana into the Dakotas, Minnesota and western Wisconsin. Recent wet weather over the past week across the north-central U.S. will only increase flood/flash flood potential given existing wet soils. As the upper trough continues east into the Plains on Thursday, upper level ridging and a warming trend can be expected across the West Coast states, with high temperatures returning into the 90s for the Great Valley of California for Thursday. Hot weather will also be found in many locations east of the Rockies through Thursday with high temperatures from the mid 80s to the middle and upper 90s from the middle and lower Mississippi River Valley to the East Coast. Record breaking heat will be possible on Wednesday and Thursday in and around the southern Appalachians with highs potentially reaching into the upper 90s for a few locations. Otto Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php