Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Thu Apr 04 2019 Valid 12Z Thu Apr 04 2019 - 12Z Sat Apr 06 2019 ...Flash flooding and severe weather both possible for the Lower Mississippi Valley on Thursday... ...Precipitation chances increasing for the West through the end of the week... Ahead of a low pressure system, widespread thunderstorms are expected on Thursday across the Lower Mississippi Valley and into the Tennessee Valley and Southeast. A Slight Risk of excessive rainfall/flash flooding is in effect for parts of the Lower Mississippi Valley toward the Central Gulf Coast, and the Storm Prediction Center has outlooked a Slight Risk of severe weather in the Lower Mississippi Valley as well. Farther north, rain is possible in the Middle Mississippi Valley to Ohio Valley, with snow or mix possible to the north in parts of the Upper Mississippi Valley. While precipitation amounts are forecast to be light, any amount of precipitation could exacerbate ongoing flood concerns for that region. The potential for snow will move into the Upper Great Lakes region by Thursday night, and into the Northeast on Friday. Snow of 1 to 3 inches is possible for the Upper Great Lakes region and the interior Northeast, with a light glaze of freezing rain possible as well. A couple of upper-level troughs will move into the western U.S. over the next couple of days, along with associated fronts at the surface. This will lead to increasing precipitation along the West Coast on Thursday and the Intermountain West and Rockies by Friday. Lower elevation rain and higher elevation snow is expected, and the highest snowfall totals are forecast in the Sierra Nevada and the Bitterroot Range in Idaho, with 6 to 10 inches of snow possible there. As upper-level energy pushes into the Southwest late Friday, another round of thunderstorms is forecast for the Southern Plains on Friday and into Saturday, with severe storms possible. Scattered thunderstorms should continue in the Southeast through the next couple of days as a front lingers there. In drier air to the west, an Elevated risk of fire weather is in place for much of New Mexico and far western parts of the Texas and Oklahoma panhandles on Friday. Also regarding fire weather, parts of the Northeast could once again see conditions favorable for the spread of fires on Thursday. Temperature-wise, the central U.S. will be increasingly warm on Thursday and especially into Friday, when high temperatures are forecast around 10 to 20 degrees above average. California will be a bit cooler than average with weather systems coming through the West, and the Northeast is expecting colder than average high temperatures as well. Overnight lows will be above average across basically the entire CONUS by Saturday morning, after cooler than average lows are expected in the Northeast on Friday. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php