Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EST Sun Feb 16 2025 Valid 12Z Sun Feb 16 2025 - 12Z Tue Feb 18 2025 ...Widespread showers with a line of strong to severe thunderstorms moving across the East Coast today as flash flood threat diminishes across the Ohio and Tennessee Valleys... ...Widespread moderate to locally heavy snowfall along with increasing winds from the Great Lakes to New England today with a period of sleet/ice from upstate New York to interior New England... ...A surge of arctic air will spread southward across the northern U.S. for the next couple of days with snow developing from the northern Rockies to the north-central Plains... ...Pacific system will bring more lower-elevation coastal/valley rain and higher elevation snow to the Pacific Northwest... An intensifying low pressure system responsible for the latest round of impactful heavy rain event across the mid-Mississippi, Ohio and Tennessee Valleys will continue to expand in size and track northeastward into New England by this evening. Flash flooding threat across these impacted areas will diminish as the heavy rain ends behind the system. Meanwhile, a solid line of strong to severe thunderstorms, with possibly damaging winds, will sweep from west to east across the East Coast today just ahead of a potent cold front trailing south from the cyclone center. The front will be moving off the East Coast later this afternoon, ending the severe weather threat for the Eastern Seaboard. Near and to the north of the cyclone track though, widespread impactful wintry weather can be expected to move through the lower Great Lakes and New England today with moderate to heavy snowfall. Areas ahead of and near the cyclone track will likely see a period of sleet/ice, which can spread as far inland as the Adirondacks in upstate New York, across the higher-elevation of interior New England during the day today, and then through the southern half of Maine into the evening. The deep low will also bring increasingly strong winds across much of the East Coast. Arctic air will rush in behind the big storm for the entire eastern U.S. for tonight, changing the rain to snow along the western slopes of the central Appalachians where blizzard conditions are possible over the western panhandle of Maryland. These activities should slowly wind down as the system moves farther away but lake-effect snow will once again makes its appearance along the Snow Belt downwind from the Great Lakes Monday and into Tuesday. Meanwhile, moisture from the next Pacific system will continue to bring unsettled weather into the Pacific Northwest and northern California through the next couple of days with lower-elevation rain and mountain snow expected. The moisture will then penetrate further inland and interact with an arctic front that will remain stationary along the spine of the Rockies. Upslope snow will develop later today into Monday over the northern Rockies with some moderate to locally heavy snow accumulations possible. The snow will also spread into the northern High Plains and toward the north-central Plains on Monday. By Monday night, the coverage of the snow will expand into the central Plains as the arctic airmass dips farther south and a wave of low pressure forms in the southern Plains on the arctic front. By Tuesday morning, the risk of freezing rain will begin to increase over central Oklahoma. The aforementioned arctic air mass will be another major weather story as well-below-average to dangerously cold temperatures overspreads the eastern half of the country behind the big storm, especially for the northern Plains. Life-threatening cold is expected for the northern Plains with low temperatures into the -30s near the Canadian border for the next couple of mornings. High temperatures will remain below zero. Gusty winds will lead to windchill of 60 degrees below zero. Conditions this cold can lead to frostbite in a matter of minutes. Further south, forecast highs in the teens and 20s will be common across the central Plains into the Midwest with 40s and 50s from Texas eastward into the lower Mississippi Valley. More intense cold is expected here further into next week. After a mild start ahead of the front along the East Coast, colder temperatures will overspread these areas as well, with highs on Monday dropping into the 20s to 40s for the Mid-Atlantic, 40s and 50s for the Southeast, and 60s into Florida. Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php