Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 322 PM EST Fri Mar 12 2021 Valid 00Z Sat Mar 13 2021 - 00Z Mon Mar 15 2021 ...Severe thunderstorms and flash flooding possible over portions of the Central/Southern Plains and the Mississippi Valley through Sunday... ...Major winter storm to impact the Central Rockies and central High Plains Friday evening and throughout the weekend... ...Critical risk of fire weather possible for much of New Mexico and parts of western Texas... A stationary front draped across the Central/Southern Plains and Middle Mississippi Valley is expected to be the focal point for heavy rain and potentially severe thunderstorms throughout the weekend. The Storm Prediction Center has issued a Slight Risk for severe thunderstorms for northern Texas and western Oklahoma into tomorrow morning. Damaging wind gusts, large hail, and isolated tornadoes are expected to be the main threats with these storms. The potential for severe weather will continue throughout the period, with the primary region of concern tomorrow being a Enhanced Risk area extending from the eastern Texas Panhandle to western Oklahoma, southeastern Arkansas and northwestern Mississippi will be at greatest risk on Sunday. Moisture pulled northward from the Gulf of Mexico and an active, very slow moving frontal boundary will serve as the ingredients in the recipe for high rain rates over middle America. This evening into tomorrow rainfall totals of one to two inches will be possible over the eastern Central Plains and Middle Mississippi Valley. Having already been subject to two to three inches of rain in the past 24 hours, thereby saturating the soils, the Weather Prediction Center has issued a Slight Risk of Excessive Rainfall for portions of these regions and Flood Warnings and Watches are currently in effect. As the frontal boundary lifts into the Central Plains on Saturday the heavy rain, thunderstorms, and threat for flash flooding will shift as well. With rainfall totals in excess of two to three inches in 24 hours possible over the Central Plains Saturday into Sunday, a Slight Risk of Excessive Rainfall will remain in effect for the region through Sunday. Out West, a deep cut-off upper-level low over the Southwest will be the driving force behind a significant winter storm set to impact the Central Rockies and the central High Plains throughout the weekend. Prior to the main event, heavy snow could fall across portions of the Central Great Basin and Southwest, with high elevation regions of Utah and Arizona likely to see six inches of snow by tomorrow morning. Showers and thunderstorms will also be possible over southern California and southwestern Arizona into the early morning hours. A low pressure system forming over the Central Great Basin Friday night will produce the first round of snow Friday into Saturday. As the weekend progresses, this low is forecast to join with the system in the Central Plains to produce a mature occluded cyclone, which will continue the heavy snowfall over the Central Rockies and the central High Plains through Sunday. By the end of the weekend, it is highly likely that one to two feet of snow will have fallen across the Front Range of northern Colorado, the Laramie Range in Wyoming, and the I-25 urban corridor, while accumulations of over a foot are possible over the central High Plains. Strong winds gusting from 30 to 40 mph are also expected to accompany the heavy snow fall rates of one to two inches per hour. This will create near blizzard conditions, making road and air travel difficult if not impossible. Winter Storm Watches and Warnings have been issued for much of Wyoming and Colorado as well as northeastern Utah and the western portions of Nebraska and South Dakota. Some light wintry precipitation ahead of a cold front is possible over interior New England early on Sunday. In the Upper Midwest, high temperatures 20 to 30 degrees above normal have been forecasted for Saturday. A cold front moving through the Pacific Northwest on Sunday will bring precipitation of all kinds to the region and northern California. Over the southern High Plains, dry conditions and gusty downslope winds south of the developing winter storm will promote elevated to critical fire danger across these areas into the weekend. Zavadoff Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php