Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 426 PM EDT Wed Apr 21 2021 Valid 00Z Thu Apr 22 2021 - 00Z Sat Apr 24 2021 ...More winter weather forecast over northern New England through Friday, and another shot of snow expected in the Mountain West... ...Record cold temperatures will expand eastward into the Ohio Valley and Mid-Atlantic Thursday morning... ...Fire weather threat increasing over the Desert Southwest through tomorrow, as well as over the Southeast U.S. coast today... Much of the active weather today will be associated with an intensifying low pressure system currently lifting northeast into New England, with snow showers and mixed rain/snow moving through the Adirondacks and Green ranges. By tonight, a swath of wet snow is expected to expand northeastward near the Canadian border from New York into far northern New England through Friday morning as the storm center passes just to the south. Total snowfall amounts of 4 to 6 inches are forecast in these areas with 8 to 12 inches possible near the northern tip of Maine and New Hampshire. As such, Winter Weather Advisories are in effect for portions of northern New York extending toward the northern tip of Maine. Meanwhile in the Midwest, cold air flowing over the Great Lakes will bring chances of lake-enhanced snow to the region, with 2 to 3 inches forecast downwind of the lakes. Precipitation will fall as liquid in the Mid-Atlantic and southern New England, with quick moving showers and thunderstorms anticipated this afternoon as a cold front sweeps through the region. Some storms may be strong to severe ahead of the front; the Storm Prediction Center has issued a Slight Risk of severe thunderstorms for the Mid-Atlantic coast to southern New England through this evening, primarily for a threat of damaging wind and hail. Unseasonably cold air is still on track to linger over the central U.S., before expanding toward the eastern U.S Thursday, leading to widespread Freeze Watches and Warnings that cover these respective regions. Numerous daily record low temperatures are forecast to be tied or broken Thursday morning as temperatures dip to below freezing--around 20-25 degrees below average for late April. Residents in these areas are encouraged to take preventative measures to mitigate the impacts of sub-freezing temperatures on vulnerable vegetation if possible. By Friday, the cold airmass will moderate as it drifts east, although low temperatures will remain around 10 degrees below normal in the Central U.S., with lows hovering in the mid-30's to 40's. Some record lows may be threatened in the Mid-Atlantic Friday morning, but temperatures are forecast to remain above freezing. In the western U.S., a low pressure system will bring lingering light snow across the central Rockies for the next few days while another surge of cold air from western Canada reaches the northern Rockies/High Plains on Thursday. Temperatures will once again tumble, along with a quick burst of snow, as the cold front passes through much of Montana by Thursday evening. The snow should move further south into Wyoming by Friday morning. 3 to 4 inches (up to 6 in the mountains) is possible with this activity. Meanwhile, active weather across southern Florida is expected to gradually move offshore as drier air arrives behind a front. The dry, windy conditions behind the front are forecast to increase the fire weather threat over the Carolinas today with a Critical risk of fire weather in place over the region per the Storm Prediction Center. Little improvement of fire weather conditions has occurred over Desert Southwest since yesterday; another Critical fire weather risk is in place over the region. The main area of concern will shift east tomorrow into far eastern Arizona, expanding through New Mexico, and into the Texas Panhandle. Deepening low pressure will couple with dry conditions to promote another Critical risk of fire weather in the region. Moreover, an Elevated risk of fire weather is in effect tomorrow over portions of North Dakota into Minnesota, and over Southern Washington running through Idaho and Nevada. Attention turns to the southern Plains and Southeast Friday morning as a moisture-laden frontal system develops over the area. Widespread showers and thunderstorms are likely as a warm front lifts north. The unstable airmass may be problematic for heavy rain and severe weather. Accordingly, a Slight risk of excessive rainfall and severe weather have been issued by the Weather Prediction Center and Storm Prediction Center, respectively. Stormy conditions will abate late this weekend as the system exits to the east. Asherman/Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php