Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 235 AM EST Thu Feb 18 2021 Valid 12Z Thu Feb 18 2021 - 12Z Sat Feb 20 2021 ...Major winter storm to impact the Mid-Atlantic and Northeast with heavy snow and significant ice accumulations today... ...Much below-average temperatures continue to linger over the Central/Southern Plains into the Middle/Lower Mississippi Valley... ...There is a Slight Risk of severe thunderstorms over parts of the Southeast today, Pacific storm system to bring unsettled weather to the Northwest and northern Rockies... The headlining weather story today is a winter storm tracking along the Southeast coast that produces heavy snow and significant ice accumulations across the Mid-Atlantic. The swath of heaviest snowfall is forecast to occur from the Appalachians of Virginia and West Virginia to northern Maryland and southern Pennsylvania. Snow totals of 6 to 8 inches are possible with localized totals up to a foot in the Appalachians possible. Treacherous travel conditions and delays are likely in these areas. A little farther south, significant and disruptive ice accumulations are anticipated in the Mid-Atlantic. Between a quarter to a half inch of ice accumulation is expected from the northern North Carolina Piedmont to southern Virginia. Some locations could receive a dangerous half inch to three quarter of an inch in these aforementioned areas. The result will be dangerous travel conditions, numerous power outages, and extensive tree damage. The footprint of a tenth to a quarter inch stretches as as north as the I-95 corridor from the Washington D.C. to Philadelphia metro areas. Snow eventually reaches the Northeast the second half of the day and continues into Thursday night. Snow totals of 3 to 6 inches are possible from the Lower Hudson Valley to southern New England. The worst of the snow and ice will be over in the Mid-Atlantic but lingering areas of sleet and freezing rain could prompt icy travel conditions into Friday morning. The prolonged stretch of frigid temperatures courtesy of a strong Arctic high pressure system continues to gradually loosen its icy grip over the Heartland. That said, abnormally cold temperatures will hang around through the end of the work-week. Record cold daily maximum and minimum temperatures are likely to transpire in the South Central U.S. through Saturday morning. The Plains and Mississippi Valley can expect daily temperature anomalies ranging between 20 and 30 degrees below normal. Thursday also looks to be quite chilly in the Mid-Atlantic as the previously mentioned winter storm unfolds across the region. After a very warm stretch in recent days, Florida will enjoy one more day of summer-like temperatures before a passing cold front ushers in the return of below normal temperatures. The Sunshine State will witness highs in the 80s throughout much of the state today, but generally sit in the 60s on average for highs on Saturday. Elsewhere precipitation-wise, the cold front sweeping through the Southeast will trigger heavy showers and thunderstorms with some storms potentially becoming severe. As a result, the Storm Prediction Center has issued a Slight Risk for severe weather from the Florida Panhandle and southern Georgia to far southern South Carolina. There is also a Marginal Risk for excessive rainfall for these same areas including eastern South Carolina and eastern North Carolina. Showers and thunderstorms will linger along the Southeast coast Friday morning as a cold front pushes west to east. Florida will continue to experience scattered showers and storms on Friday before drier conditions arrive Friday night as high pressure builds in from the west. Meanwhile, a Pacific storm system makes landfall in the Pacific Northwest this afternoon delivering more coastal/valley rain and mountain snow to the region. A steady onshore flow continues favors additional upsloping winds along the Cascades while Pacific moisture advances deeper into the Intermountain West. Through Friday night, 1 to 2 feet of snow is forecast to pile up along the Cascade Range with 6 to 12 inches of snow possible in the Sawtooth, Bitterroots, and Teton mountain ranges. Those along the coastal range of northern California and western Oregon/Washington may receive 1 to 2 inches of rain through Friday night. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php