Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 349 PM EDT Tue Mar 23 2021 Valid 00Z Wed Mar 24 2021 - 00Z Fri Mar 26 2021 ...Heavy rain and possible severe thunderstorms to drench the central Gulf Coast and Tennessee Valley over the next couple of days... ...Heavy mountain snow expected for the Southern Rockies... ...Critical Risk of fire weather remains in place from portions of southeastern Arizona to West Texas today... A potent low pressure system in the Central Plains this afternoon is gradually tracking northeast while sporting an impressive areal extent of precipitation that stretches from the northern Great Lakes to the Gulf Coast. The central Gulf Coast most notably features the best odds of witnessing heavy rainfall and severe weather through tonight. A Slight Risk of Excessive Rainfall has been issued for portions of the area today, along with a Slight Risk of severe weather. Severe storms and locally heavy rainfall are also possible in the middle Mississippi Valley. As the occluded low enters the Great Lakes by Wednesday, its associated shield of rain will overspread the region throughout the day. Light snow will be possible across northern Minnesota. Meanwhile, a cold front associated with this storm system is forecast to stall and lift north as a warm front over the South-Central U.S. Wednesday afternoon. This sets the stage for another round of severe weather Wednesday evening, highlighted by a Slight Risk for severe thunderstorms in the Lower Mississippi Valley. Meanwhile, another frontal boundary near the central Gulf Coast looks to produce more heavy rainfall embedded within strong thunderstorms. Yet another Slight Risk for Excessive Rainfall is in place for roughly the same area on Wednesday that is currently experiencing heavy rain this afternoon. The heavy rain and severe weather threat does not end Wednesday and extends into Thursday, as an even more robust low pressure system enters the Lower Mississippi Valley. This next round of active weather is expected to include a possible outbreak of severe thunderstorms across the Lower Mississippi Valley and Southeast, as well as downpours and potential flash flooding as far north as the Tennessee Valley. In total through Thursday night, over 5 inches of rainfall is possible from eastern Louisiana to southern Alabama, with 2 to 4 inches of rain expected from northern Mississippi to western Tennessee. Flash Flood Watches remain in effect for portions of the central Gulf Coast through Thursday night. Farther West, a cold front is moving quickly southward across the Southwest this afternoon with a broad area of rain and snow showers behind. A fresh injection of below normal temperatures and gusty winds follow the front as well. The front will slow over the Southwest tonight ahead of an amplifying upper trough over the Four Corners region. This upper trough then triggers periods of mountain snow over the southern Rockies with totals ranging from 1 to 2 feet in the highest elevations of northern New Mexico. Another front is forecast to enter the Northwest U.S. with additional precipitation on Wednesday and Thursday. The upper trough is forecast to quickly weaken Wednesday evening, closing the door on additional snowfall in the southern Rockies, but it does help to produce scattered showers in parts of the Southern Plains. Winter Storm Warnings and Winter Weather Advisories are in affect across much of New Mexico in a anticipation for the upcoming snowfall. Elsewhere, conditions remain favorable for fire weather over parts of the Southwest and southern High Plains this evening due to low relative humidities combined with gusty winds and dry fuels. Red Flag Warnings are in place, along with Elevated to Critical Risks of fire weather. Some welcomed precipitation is anticipated in these areas through Thursday. The Northwest will see yet another round of precipitation as a cold front swings through the region Wednesday evening, where several inches of mountain snow is possible throughout the region. Lastly, high pressure supplying one more day of welcome warmth and dry conditions throughout the Northeast gives way to an approaching frontal system off the East Coast on Wednesday. This storm system is set to deliver periods of rain to the Northeast. However, the above average temperatures in the East will rebound Thursday and could break several daily records. This includes both record warm highs and lows throughout the Northeast and Florida. Snell/Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php