Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Wed Apr 21 2021 Valid 12Z Wed Apr 21 2021 - 12Z Fri Apr 23 2021 ...A low pressure system will continue to bring wet snow across northern New England through Thursday morning... ...Light snow lingers across central Rockies as the another surge of cold air brings additional snowfall into the northern Rockies... ...Subfreezing record cold temperatures this morning across much of the south-central U.S. will shift to parts of the eastern U.S. Thursday morning... ...Fire weather threat increasing over the Desert Southwest 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 which is forecast to move across the central Appalachians and into New England through tonight. A swath of wet snow is expected to expand northeastward near the Canadian border from New York into northern New England through Friday morning as the storm center passes just to the south. Total snowfall amounts of 6 to 10 inches is forecast in these areas with up to 12 inches possible over the northern tip of Maine. Further south in the Mid-Atlantic to southern New England, some showers and embedded thunderstorms are expected this afternoon as a cold front moves quickly through the region. In fact, the Storm Prediction Center issued a Slight Risk of severe thunderstorms for the Mid-Atlantic coast to southern New England for today. In the wake of the developing storm system, unseasonably cold air will continue to surge into the central U.S. today and tomorrow, leading to widespread Freeze Watches and Warnings that cover much of the central U.S., Midwest and the interior eastern U.S. Numerous daily record low temperatures are forecast to be tied or broken this morning and 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. Meanwhile, active weather across Florida has been edging very slowly southward into southern Florida ahead of a slow-moving front. A low pressure wave forming on the front could bring additional heavy showers and thunderstorms today across central Florida. Improving conditions should begin Wednesday morning as the wave moves off into the Atlantic and rain chances decrease across southern Florida. While excessive rain may be problematic in Florida, dry, windy conditions will set the stage for a fire weather threat in Arizona over the next three days as low pressure deepens in the region. Accordingly, the Storm Prediction Center has issued an Elevated Risk of fire weather today, and a Critical Risk tomorrow, with the potential for additional impactful fire weather also highlighted on Friday. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php