Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 322 PM EST Fri Feb 12 2021 Valid 00Z Sat Feb 13 2021 - 00Z Mon Feb 15 2021 ...Significant ice storm to develop over the Mid-Atlantic on Friday evening into Sunday evening... ...Winter storm to impact Washington State and Oregon through Sunday... ...Significant Winter Storm to Arrive over the Southern Plains on Sunday into Monday... ...Bitter arctic air to remain entrenched across the Plains and Mississippi Valley... Bitterly cold air will engulf the Plains with temperatures 35 to 55 degrees below average. A quasi-stationary front at the leading edge of the cold air mass will remain over the Southeast through Sunday evening. An area of low pressure moving along the coast/up this boundary will spread precipitation in the form of rain/freezing rain and sleet across the Mid-Atlantic and Northeast Saturday and Sunday. While the probability for significant icing (>0.25") has decreased, there is still good potential for more than 0.1" from northern North Carolina through central Virginia and into the I-95 corridor from Washington, D.C. to Philadelphia, Pennsylvania on Saturday. Locally more than 0.25" is still likely. Light ice accumulations are likely as far north as New York City and Southern New England on Sunday. The same storm will produce rain and embedded thunderstorms over parts of the Southeast through Sunday evening. Ice accumulation on trees & power lines could lead to power outages. Ice accumulation on sidewalks and roads may make travel difficult. A storm just off the Northwest Coast will move onshore overnight Friday, moving southeastward to the Four Corners Region by Sunday. The system will produce widespread snow across the mountains and into Washington and Oregon's lowlands through Sunday. Significant snowfall is forecast for both Portland and Seattle, with several inches likely from Friday evening into Saturday. Additionally, icing in excess of 0.25" is forecast for parts of northwest Oregon through Sunday. Significant disruptions to travel are likely to continue with ice, snow, and wind, contributing to power outages. Upper-level dynamics will help produce snow across the Northern/Central Rockies into the Central Plains Friday night into the Middle Mississippi Valley. It will continue into parts of the Great Lakes and Ohio Valley on Saturday, with a short break over parts of the Plains and Mississippi Valley on Sunday. Furthermore, the very cold air over the relatively warm Lake Superior will produce lake-effect snow over parts of the Upper Peninsula of Michigan through Sunday evening. A major winter storm is expected to develop out over the Southern Plains Sunday into Monday, with a large area of snow, sleet, and freezing rain expected. While confidence is high on an impactful winter storm, there remains uncertainty with the location and magnitude of the heaviest snow, ice, and rain/freezing rain. However, it appears likely that there will be significant travel disruption and concern for power outages across a large area of the Southern Plains going into early Monday. Snow will develop over parts of Southwest/Southern Rockies overnight Saturday, with snow developing over the Central/Southern Plains on Sunday morning. The snow will spread into parts of the Middle/Lower Mississippi Valley. Rain will develop along the Western Gulf Coast also on Saturday evening into Sunday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php