Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 259 PM EST Thu Mar 11 2021 Valid 00Z Fri Mar 12 2021 - 00Z Sun Mar 14 2021 ...Severe thunderstorms and flash flooding possible over parts of the Central/Southern Plains and Middle Mississippi Valley through Saturday... ...Warm temperatures 10 to 20 degrees above average found from the Southeast to the Northeast Friday... ...Critical risk of fire weather for central and southern New Mexico... ...Significant winter storm to begin Friday evening into Saturday morning across the Central Rockies and central High Plains... A low pressure system with a frontal boundary extending from the Southwest to the Northeast is forecast to move into Canada overnight. Ahead of the cold front, temperatures will rise into the 60s and 70s across the East Coast. As the system propagates quickly northeast the northern half of the frontal boundary is expected to keep pace, dousing the Northeast in light to moderate rain into the early morning Saturday. Conversely, the southern half of the frontal boundary will more or less stall over an area extending from the Central/Southern Plains to the Ohio and Tennessee Valleys. Showers and thunderstorms will persist along the leading edge of the frontal boundary, some of which could become severe. The Storm Prediction Center has issued a Slight Risk for severe thunderstorms for portions of the Central Plains and Mississippi Valley through tomorrow morning. Damaging wind gusts and large hail are expected to be the main threats with these storms. The threat for severe weather will continue throughout the period, with the primary region of concern tomorrow being a Slight Risk area extending from the Texas Panhandle to southwestern Oklahoma, while central Texas, central Oklahoma and a portion of southern Kansas will be at greatest risk on Saturday. These thunderstorms will also have the potential to cause flash and urban flooding as they develop and remain over the same areas due to the slow progression of the frontal boundary. At present, the Weather Prediction Center has indicated a Marginal Risk for Excessive Rainfall and Flood Watches have been issued for portions of the Middle Mississippi and Ohio Valleys, where one to two inches of rainfall will be possible through tomorrow evening. The risk for flash flooding in these regions will be carried throughout the period. As showers and thunderstorms cluster over the Central/Southern Plains Friday into Saturday rainfall totals in excess of two to three inches will be possible, making flash flooding a concern in these regions throughout the early weekend. On the very southern end of this frontal boundary over New Mexico and western Texas, persistent dry conditions, exacerbated by a passing cold front this evening, combined with high winds associated with the frontal passage will create a Critical Risk of fire weather throughout the period. Much of New Mexico will be at greatest risk for fire weather and Red Flag Warnings are currently in effect. A large upper-level low spinning above the southwestern U.S. will be the catalyst for an upcoming significant winter storm across the Central Rockies and central High Plains. Before the system fully develops this weekend, heavy snow could fall across the higher elevations of the Intermountain West and Southwest. Portions of Utah and Arizona could see over 6 inches of snow by Saturday morning. Heavy mountain snow and lower elevation heavy rain will also remain possible across southern California through Friday. As the upper-level low moves eastward, an area of low pressure is expected to develop across the southern High Plains on Friday and produce heavy snow across central Colorado and southeast Wyoming this weekend. Light snow is forecast to develop Friday evening across the region; however, much of the winter weather impacts are forecast to occur later in the day on Saturday and throughout much of Sunday. Widespread travel impacts are likely as strong winds combined with snowfall rates of one to two inches per hour could produce near blizzard conditions. Winter Storm Watches have been issued and include southeast Wyoming, northeast and central Colorado, as well as western Nebraska. Zavadoff/Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php