Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 354 AM EDT Mon Apr 12 2021 Valid 12Z Mon Apr 12 2021 - 12Z Wed Apr 14 2021 ...Scattered showers and a few thunderstorms are possible from the Great Lakes to the Northeast today; accumulating wet snow expected the next couple of days in the far Northern Plains... ...Mountain snow gradually develops and expands across the northern and central Rockies; lingering frontal boundary to trigger showers and thunderstorms in the South Central U.S... ...Favorable conditions for Elevated to Critical fire weather conditions in the Southwest to continue into the middle of the week... An upper level blocking jet stream pattern across North America will result in a low pressure system becoming quasi-stationary over the Upper Midwest for the next couple of days. The area of low pressure works in tandem with an upper level low tracking into the northern Mid-Atlantic today to generate scattered showers and possibly some embedded thunderstorms from the Great Lakes to the Northeast Coast through Monday night. Along with unsettled weather, this blocking pattern over Canada allows for colder than normal conditions to set up shop from the Northwest into the Nation's Heartland the first half of the week. In fact, enough sub-freezing air aloft will be available for wet snow to develop near the Canadian border and over the northern Plains. An extended period of steady snowfall rates is forecast to result in 6 to 12 inches of snow accumulations by Wednesday morning for the northern half of North Dakota into northwestern Minnesota. Farther west, the blocking pattern will also force a cold upper low to form and dip across the Pacific Northwest toward the Great Basin for the next couple of days. This brings colder temperatures together with gradual development and expansion of mountain snow across the Northwest, the northern Great Basin, and both the northern and central Rockies. The coldest temperature departures (15 to 20 degrees below normal) are forecast to occur in the northern High Plains both Monday and Tuesday. In contrast, warmer and wetter conditions are anticipated in the South Central U.S. to kickoff the week. A Slight Risk for severe weather is in place over central Texas today with a Marginal Risk (for both severe weather and excessive rainfall) over the Lower Mississippi Valley on Tuesday. In the Southwest, low relative humidity levels along with breezy conditions and dry fuels will support an Elevated Risk for fire weather in parts of Arizona and New Mexico. There is also an Elevated Risk for fire weather in central Nebraska today as well. Conditions only grow more favorable for fire weather as the aforementioned upper trough in the Northwest deepens, creating a stronger wind field along with persistent low humidity levels and dry fuels. This has resulted in a Critical Risk for fire weather in the lower Great Basin on Tuesday. Depending on the position and intensity of the upper trough, fire weather could remain an ongoing issue in the Southwest and lower Great Basin into the middle of the week. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php