Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Wed Mar 20 2024 Valid 00Z Thu Mar 21 2024 - 00Z Sat Mar 23 2024 ...Snow showers forecast throughout the Northeast over the next few days; accumulating snowfall forecast in portions of New England... ...Light to moderate snow spreads from the northern Plains to the Great Lakes by Friday; strong winter storm expected this weekend... ...Shower and thunderstorm chances return to the Southern Plains and Gulf Coast... The forecast remains on track for a low pressure system to deepen this evening across the Interior Northeast and New England, producing periods of snowfall while also reinforcing lake enhanced snow showers in its wake. Minor to locally Moderate potential winter storm impacts can be expected with this round of snowfall through tomorrow afternoon focused over portions of northern New Hampshire and Maine, where high probabilities (80-90%) of at least 4 inches of snow are noted. Meanwhile, a separate winter storm is anticipated to produce a swath of snow beginning tonight between the northern Plains and Great Lakes through the end of the work week as a precipitation shield develops along an emerging frontal wave, which shifts eastward by tomorrow night. High probabilities for at least 4 inches of snow remain across northwest Montana, with medium to high probabilities (40-80%) extending from north-central Montana to central Minnesota, including southern South Dakota, where a swath of Winter Weather Advisories are in effect. Greater chances for moderate to heavy snow shifts to the Upper Midwest and Great Lakes by Friday, where there is the potential for up to 10-12 inches of snow. Beyond this first round of Northern Tier snowfall, the pattern will remain quite active looking into this weekend as confidence is increasing that a large storm system will produce a swath of heavy snow, freezing rain, and sleet across portions of the Northern Plains and Upper Midwest into early next week. Residents should remain weather aware and up to date with the latest forecast as details change with these next two dynamic snowfall events. Elsewhere, unsettled weather is set to return to the southern Plains, Gulf Coast, and parts of the West Coast. An uptick in shower and thunderstorm activity is expected tonight and tomorrow over portions of Oklahoma and Texas as a stubborn upper-low ejects into the Southern Plains tonight. By tomorrow, rain could become heavy enough along the western Gulf Coast and southeast Texas to produce isolated flooding concerns. This system is forecast to progress eastward into the Gulf of Mexico on Friday, spreading showers and thunderstorms along the entire Gulf Coast, as well as eventually Florida and the Southeast by late Friday. However, both the severe and flooding threat associated with this system remain marginal. For the West Coast, light to moderate rain is expected to move inland across northern California and the coastal Midwest on Friday. As the axis of precipitation along a frontal boundary intersects the Sierra on Friday night, heavy snow is possible throughout the mountainous terrain. Asherman/Snell Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php