Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EST Mon Feb 15 2021 Valid 12Z Mon Feb 15 2021 - 12Z Wed Feb 17 2021 ...Over 150 million Americans are currently under Winter Storm Warnings, Ice Storm Warnings, Winter Storm Watches, or Winter Weather Advisories as impactful winter weather continues from coast-to-coast... ...Major winter storm to spread heavy snow and significant ice accumulations from the Southern Plains and Ohio Valley to the Northeast... ...Additional winter weather is expected for the Northwest this morning, spreading south and east through Tuesday... ...Frigid Arctic air and dangerously cold wind chills to persist in the Heartland through a good part of the week... ...Severe thunderstorms, heavy rain, and warm temperatures are expected for southern Georgia and Florida... An unprecedented and expansive area of hazardous winter weather continues into Presidents Day as disruptive snow and ice accumulations transpire across the South Central U.S. early this morning. This impressive onslaught of wicked wintry weather across much of the Lower 48 is due to the combination of strong Arctic high pressure supplying sub-freezing temperatures and an active storm track escorting waves of precipitation from coast-to-coast. While the current areas of snow and wintry mix over parts of the Southern Plains will conclude later this morning, bitterly cold temperatures will limit the amount of melting today, and thus treacherous travel conditions are likely to persist. Heavy snow and freezing rain are forecast to advance northeastward today from the Mississippi and Ohio Valleys to the Northeast. A large swath of 6 to 12 inches of snow is forecast from the Ohio Valley and eastern Great Lakes to northern New England. South of the heavy snow axis, freezing rain is expected to cause a plethora of problems with over a tenth of an inch of ice in the forecast from far east Texas northeastward to southern New England. Significant ice amounts of a quarter to a half inch are expected in portions of the Lower Mississippi Valley and the Mid-South leading to dangerous travel conditions, numerous power outages, and extensive tree damage. Precipitation will likely stay rain for the southern Mid-Atlantic and Southeast where cold air is more limited. In the West, another surge of Pacific moisture is accompanying a frontal system forecast to make landfall along the Pacific Northwest coast this morning. More wintry weather is possible in lower elevations of the Pacific Northwest, while locally heavy rain could create localized flooding issues in far southwestern Oregon and far northwestern California early this morning. Farther inland, the Great Basin and Intermountain West can expect more rounds of higher elevation snowfall with the more intense snowfall rates occurring on Presidents Day. Snowfall accumulations forecasts through Tuesday suggests 1 to 2 feet is likely in the Cascades and Northern Rockies through Tuesday (localized totals over 3 feet are possible), with measurable snow extending into the Wind River Mountains/Tetons, Wasatch, and Central/Southern Rockies as well. Avalanches remain a big concern in portions of Utah. This storm system is expected to be the next winter storm to impact the South Central U.S. mid-week. The aforementioned Arctic high across the central U.S. is forecast to slowly moderate as the week progresses, but still maintain a firm and icy grip over the Heartland to open the week. Teeth-chattering cold temperatures are expected to continue between the Rockies and Appalachians through Tuesday with lows in the -20s and -10s for the Northern/Central Plains and Upper/Middle Mississippi Valley. Temperature anomalies are likely to be 25 to 45 degrees below normal for much of the central and southern Plains today with a carbon-copy of similar anomalies expected again on Tuesday. In addition, Wind Chill Warnings and Advisories reach as far south as the Southern Plains and as far east as the Ohio Valley. Hundreds of daily low maximum and minimum temperatures have been/will be broken during this prolonged "polar plunge", with some February and even all-time low temperature records in jeopardy. Meanwhile, showers and thunderstorms are ongoing across parts of the Southeast near and along a stationary front. Severe thunderstorms are in the forecast today in southern Georgia and into the Florida peninsula where a Slight Risk of severe weather is in place courtesy of the Storm Prediction Center. Moderate-to-heavy rainfall across portions of Florida, Georgia, and the eastern Carolinas is anticipated Monday afternoon and evening. Florida will remains the warm spot in the CONUS with highs above normal and generally in the 80s. A few daily record high temperatures may be challenged in localized areas of the Sunshine State this afternoon. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php