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Image: NOAA
December 21, 2020
β Odds for a White Christmas are rising for the Ohio Valley, Appalachia, and parts of the interior Mid-Atlantic...
From a historical perspective, the odds of a White Christmas for the Ohio Valley, and lower elevations in the Appalachian Mountain Chain are less than 25%. In the northern Ohio Valley a 1 in 4, or 1 in 5 chance dwindles to a 1 in 10 chance farther south. When you reach the far southern Ohio Valley into the northern Tennessee Valley it shrinks farther to 1 in 20. This year, the risk of seeing a White Christmas is on the rise thanks to a storm system organizing, deepening, and delivering cold air at the right time.
A strengthening cold front will push into the region late Wednesday into early Thursday morning. Out ahead of it, southerly flow will lead to many areas reaching the upper 40s to upper 50s for highs. This will likely catch people off guard with well-above normal temperatures, but it is that tenperature gradient that will allow a southern wave to develop in the vicinity of Atlanta, Georgia, late on Wednesday. That low will rapidly deepen and freight train cold into the Ohio Valley and Appalachia during Christmas Eve, Thursday.

Image: NAM/Pivotal
December 21, 2020
As the low continues to feed on the warm, moist flow in the warm sector against the cold, dense air behind it, heavy precipitation will break out. Intense thunderstorms, and heavy rainfall can be expected, where places just last week cashed in on a heavy snowfall as highs soar into the 60s. Behind the front, heavy snow squalls and temperatures plummeting into the teens and twenties will set the stage for accumulating snow, leading to a solid chance of areas in the Ohio Valley and Appalachia receiving a White Christmas. Specifics are still 48-60 hours out, due to the nature of this storm being in its formative stages. Bottom line, though, is this secondary wave will become a high impact storm for Christmas Eve and Christmas Day.
βοΈ Forecast Provided By: Joshua Ketchen
βοΈ Forecast Provided By: Joshua Ketchen
- π‘ Winter Snowfall Forecast
Show and hide layers π‘ The 2020/21 SWC Winter Snowfall Forecast illuminates a wintry picture over a large portion of America. A La Nina favored large-scale pattern with upper-level ridging in the west and troughing in the east was considered in developing this forecast. Other influences, from the Arctic to the North Atlantic, could play a major role on how storm systems progress across the country.
- Latest SWC Forecasts
- βοΈ Winter’s Last Stand for the Ohio Valley with Heavy Snow possible Friday night
- β οΈβοΈ Winter Storm Update Plus Expected Snow & Ice Totals across the Ohio Valley Region
- βπ§βοΈ Powerhouse Winter Storm to slam the Ohio Valley with Ice and Heavy Snow starting on Wednesday night through Friday
- βπ§ Potentially Dangerous Winter Storm to bring significant winter impacts to the Ohio Valley, Midwest, and Southern Plains this week!
- β See how much snow will fall across the eastern third of the Ohio Valley Sunday night/Monday morning
- β A Massive Winter Storm is expected to produce widespread accumulating SNOW across multiple regions this weekend
- β Winter to visit the Ohio Valley and Lower Great Lakes this week with Accumulating Snow and Cold
- π₯Ά Major Cold Outbreak Likely next week with “First Flakes” possible in the Midwest, Ohio Valley, and Northeast!
Latest SWC Featuresβ Catch up on the most recent weather forecasts from SWC Forecasters!
β Track severe weather hazards day or night with our interactive maps!
β Visit our social media outlets for more fresh weather content!
β Sign-Up for a storm chasing vacation with our veteran Storm Chasers and friendly Tour Guides!
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Do you have a fun weather fact or personal weather story that you would like to share with SWC Forecasters? We would love to hear about it! Send us your story at forecasters@swcforecastcenter.com.
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Do you have a fun weather fact or personal weather story that you would like to share with SWC Forecasters? We would love to hear about it! Send us your story at forecasters@swcforecastcenter.com.
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Do you have a fun weather fact or personal weather story that you would like to share with SWC Forecasters? We would love to hear about it! Send us your story at forecasters@swcforecastcenter.com.
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Do you have a fun weather fact or personal weather story that you would like to share with SWC Forecasters? We would love to hear about it! Send us your story at forecasters@swcforecastcenter.com.
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Do you have a fun weather fact or personal weather story that you would like to share with SWC Forecasters? We would love to hear about it! Send us your story at forecasters@swcforecastcenter.com.
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Do you have a fun weather fact or personal weather story that you would like to share with SWC Forecasters? We would love to hear about it! Send us your story at forecasters@swcforecastcenter.com.
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- β οΈ U.S Advisory Layers
SWC Weather Advisory Layers β οΈ Click on real-time watch, warning, and advisory polygons for critical weather information. Allow the SWC location feature to plot your location on the map. Expand the map and visit all SWC Weather Layers.
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π NOAA/NWS Surface Weather Maps display forecasted cold/warm front postions, precipitation areas, and high/low pressure centers. Forecasts span over 48 to 60 hours.
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π NOAA/NWS Surface Weather Maps display forecasted cold/warm front postions, precipitation areas, and high/low pressure centers. Forecasts span over 48 to 60 hours.
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π NOAA/NWS Surface Weather Maps display forecasted cold/warm front postions, precipitation areas, and high/low pressure centers. Forecasts span over 48 to 60 hours.
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π NOAA/NWS Surface Weather Maps display forecasted cold/warm front postions, precipitation areas, and high/low pressure centers. Forecasts span over 48 to 60 hours.
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π NOAA/NWS Surface Weather Maps display forecasted cold/warm front postions, precipitation areas, and high/low pressure centers. Forecasts span over 48 to 60 hours.
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π NOAA/NWS Surface Weather Maps display forecasted cold/warm front postions, precipitation areas, and high/low pressure centers. Forecasts span over 48 to 60 hours.
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- π§ As Winter Weather impacts become more frequent across America, it's important to brush up on the basics. Let's review how you can prepare yourself and your family for the worst of Old Man Winter!π¦ Pack an Emergency Supply Kit.
π± Charge all Communication devices.
π Winterize all family vehicles.
π Get up-to-date weather reports.
π Share your travel plans with others.
π£ Monitor road conditions.
- Latest SWC Forecasts
- βοΈ Winter’s Last Stand for the Ohio Valley with Heavy Snow possible Friday night
- β οΈβοΈ Winter Storm Update Plus Expected Snow & Ice Totals across the Ohio Valley Region
- βπ§βοΈ Powerhouse Winter Storm to slam the Ohio Valley with Ice and Heavy Snow starting on Wednesday night through Friday
- βπ§ Potentially Dangerous Winter Storm to bring significant winter impacts to the Ohio Valley, Midwest, and Southern Plains this week!
- β See how much snow will fall across the eastern third of the Ohio Valley Sunday night/Monday morning
- β A Massive Winter Storm is expected to produce widespread accumulating SNOW across multiple regions this weekend
- β Winter to visit the Ohio Valley and Lower Great Lakes this week with Accumulating Snow and Cold
- π₯Ά Major Cold Outbreak Likely next week with “First Flakes” possible in the Midwest, Ohio Valley, and Northeast!
Latest SWC Featuresβ Catch up on the most recent weather forecasts from SWC Forecasters!
β Track severe weather hazards day or night with our interactive maps!
β Visit our social media outlets for more fresh weather content!
β Join SWC Veteran Storm Chasers in Spring 2021 as we track down the most intense Supercells and Tornadoes found in the world!
- π‘ View the latest Goes-16 Visible Satellite image of the United States. This image will update every 5 minutes.
- π₯ As La Nina continues to control the overall pattern across the Western U.S., dry conditions are prevailing across Arizona, Utah, and New Mexico. These conditions are forecasted to continue through Winter 2020/21.
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