Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 323 PM EDT Tue Mar 24 2020 Valid 00Z Wed Mar 25 2020 - 00Z Fri Mar 27 2020 ...Areas of flash flooding and severe weather are expected through the evening and into the overnight hours across the Tennessee Valley and into the Southern Appalachians... ...Unsettled weather along with below average temperatures will continue across much of the West, while above average temperatures encompass much of the South... ...Accumulating snows possible Wednesday into early Thursday across portions of the Northern Plains, Upper Mississippi Valley and the Upper Great Lakes... Hazardous weather will drive an active evening and overnight period across portions of the Tennessee Valley and the Southern Appalachians as a wave of low pressure advances quickly off to the east along a front draped from the Tennessee Valley into the interior of the Southeast. Numerous showers and thunderstorms are expected across this region with an emphasis on the Mid-South where severe weather is likely to develop this evening, including a threat of large hail, damaging winds and tornadoes. Heavy rainfall associated with this will also raise the concern for flash flooding, and especially considering the wet antecedent soil conditions across the Mid-South. In fact, the Storm Prediction Center has highlighted an Enhanced Risk of severe weather, and the Weather Prediction Center has highlighted a Moderate Risk of excessive rainfall going into the overnight hours for this region. Later tonight, some of the threat of severe weather and flash flooding will cross the Southern Appalachians, but the weather will be improving across the Tennessee Valley and Southeast by early Wednesday as the aforementioned wave of low pressure reaches the Mid-Atlantic coast. Rain will shift farther north into areas of the Mid-Atlantic and southern New England on Wednesday, but conditions here should begin to improve later in the day as the low center then begins to move out to sea. Most of the eastern U.S. should then see dry and tranquil weather on Thursday as high pressure noses down over the region. Meanwhile, a strengthening upper-level trof of low pressure will be pushing slowly southeastward across much of the West, including the Great Basin and Northern Rockies over the next couple of days. This will drive an unsettled pattern throughout the Intermountain West with numerous showers that will drive low elevation rains and accumulating snowfall for the higher terrain. In fact, an additional 1 to 2 feet of snowfall is expected locally with an emphasis on the Sierra-Nevada, and the Wasatch. With this showery pattern, temperatures are expected to remain well below average across most of the West, and especially the Southwest through the remainder of the week. In contrast to this, above average temperatures will stretch through the Southern Plains and Lower Mississippi Valley on Wednesday and spread east to encompass much of the Ohio Valley, Mid-Atlantic and the remainder of the South by the end of the week. Elsewhere, Wednesday will bring much cooler temperatures to the Northern Plains as a strong cold front presses southeastward across this region. An area of low pressure moving northeastward along this front will support some accumulating snow potential Wednesday into early Thursday from the Northern Plains, across the Upper Mississippi Valley and into the Upper Great Lakes. The expectation is that these amounts will be generally light with a few inches possible. Orrison Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php