447   
FXUS01 KWBC 210751  
PMDSPD  
  
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
251 AM EST TUE JAN 21 2025  
  
VALID 12Z TUE JAN 21 2025 - 12Z THU JAN 23 2025  
  
...DANGEROUSLY COLD TEMPERATURES AND WIND CHILL VALUES TO LINGER  
FOR MUCH OF THE SOUTH AND EASTERN U.S. THROUGH MID-WEEK...  
  
...RARE WINTER STORM TO BRING HEAVY SNOW AS WELL AS AREAS OF SLEET  
AND FREEZING RAIN TO THE GULF COAST AND SOUTHEAST WITH WIDESPREAD  
TRAVEL IMPACTS EXPECTED...  
  
...EXTREMELY CRITICAL RISK OF FIRE WEATHER FOR SOUTHERN CALIFORNIA  
WILL CONTINUE INTO TUESDAY...  
  
A BITTERLY COLD AIRMASS WILL REMAIN IN PLACE FOR MUCH OF THE SOUTH  
AND EASTERN U.S. OVER THE NEXT COUPLE OF DAYS FOLLOWING AN ARCTIC  
FRONTAL PASSAGE OVER THE HOLIDAY WEEKEND. FORECAST TEMPERATURES ON  
TUESDAY WILL BE UPWARDS OF 20-30 DEGREES BELOW JANUARY AVERAGES  
FOR MOST LOCATIONS WITH HIGHS RANGING FROM THE SINGLE DIGITS AND  
TEENS IN THE MIDWEST, THE TEENS AND 20S IN THE NORTHEAST, AND THE  
20S AND 30S ACROSS THE CENTRAL/SOUTHERN PLAINS AND SOUTHEAST. MANY  
RECORD LOWS ARE POSSIBLE WEDNESDAY MORNING, ESPECIALLY ALONG THE  
GULF COAST AND INTO THE TENNESSEE VALLEY. SUB-ZERO WIND CHILLS  
WILL CONTINUE FOR THE CENTRAL/SOUTHERN PLAINS AND OHIO VALLEY, AND  
MAY EXPAND INTO THE MID-ATLANTIC AND MID-MISSISSIPPI VALLEY  
THROUGH WEDNESDAY. AFTER ANOTHER BRUTAL MORNING WITH DANGEROUS  
WIND CHILLS REACHING 30 TO 55 DEGREES BELOW ZERO, PORTIONS OF THE  
NORTHERN PLAINS WILL SEE A RETURN TO RELATIVELY WARMER, MORE  
TYPICAL JANUARY TEMPERATURES IN THE 20S AND 30S BY TUESDAY  
AFTERNOON AS DOWNSLOPING AIR FROM THE ROCKIES SPREADS EASTWARD  
ACROSS THE REGION. THESE TEMPERATURES WILL REACH THE UPPER MIDWEST  
BY WEDNESDAY, WHILE TEMPERATURES WILL ALSO MODERATE INTO THE 40S  
AND 50S FOR WESTERN PORTIONS OF THE CENTRAL/SOUTHERN PLAINS.  
  
THE COMBINATION OF THIS ARCTIC AIR REACHING THE GULF COAST AND A  
DEVELOPING LOW PRESSURE SYSTEM OVER THE GULF WILL LEAD TO A RARE,  
SIGNIFICANT WINTER STORM FOR THE GULF COAST AND SOUTHEAST THE NEXT  
COUPLE OF DAYS. A HISTORIC SNOWFALL IS POSSIBLE ALONG THE GULF  
COAST, WITH SNOWFALL RATES OF 1"/HOUR OR MORE POSSIBLE FROM  
EASTERN TEXAS THROUGH THE WESTERN FLORIDA PANHANDLE. THIS MAY  
PRODUCE SNOWFALL TOTALS AS MUCH AS 3-6" FOR THE I-10 CORRIDOR,  
INCLUDING THE CITIES OF HOUSTON, NEW ORLEANS, MOBILE, AND  
PENSACOLA. A COMBINATION OF HEAVY SNOW, SLEET, AND FREEZING RAIN  
IS EXPECTED FURTHER EAST INTO GEORGIA, NORTHERN FLORIDA, AND THE  
EASTERN CAROLINAS. THIS STORM MAY LEAD TO MAJOR HIGHWAY AND AIR  
TRAFFIC DISRUPTIONS, INCLUDING POSSIBLE ROAD CLOSURES AND FLIGHT  
CANCELLATIONS, WHICH MAY CONTINUE FOR SEVERAL DAYS EVEN AFTER THE  
SNOWFALL ENDS. POWER OUTAGES ARE ALSO POSSIBLE AND WILL EXACERBATE  
THE THREAT FROM THE FRIGID TEMPERATURES.   
  
UNFORTUNATELY, DANGEROUS FIRE WEATHER CONDITIONS LOOK TO CONTINUE  
THROUGH AT LEAST MID-WEEK FOR SOUTHERN CALIFORNIA WITH VERY STRONG  
OFFSHORE FLOW AND LOW HUMIDITY IN PLACE. THE STORM PREDICTION  
CENTER HAS OUTLINED AN EXTREMELY CRITICAL RISK OF FIRE WEATHER  
(LEVEL 3/3) FOR THE REGIONAL MOUNTAINS AROUND THE LA BASIN AS WIND  
GUSTS MAY REACH 70-100 MPH. A CRITICAL RISK (LEVEL 2/3) IS ALSO IN  
PLACE FOR THE REGIONAL VALLEYS AND COASTAL REGIONS WITH GUSTS OF  
50-80 MPH EXPECTED. A CRITICAL RISK CONTINUES FOR THE MOUNTAINS  
WEDNESDAY. ELSEWHERE IN THE WEST, CONDITIONS WILL BE DRY, WITH  
GENERALLY MILD HIGH TEMPERATURES. FORECAST HIGHS RANGE FROM THE  
40S AND 50S FOR THE PACIFIC NORTHWEST AND GREAT BASIN, THE 50S AND  
60S IN CALIFORNIA, AND THE 60S AND 70S IN THE DESERT SOUTHWEST.  
MORNING LOWS WILL BE A BIT CHILLY, HOWEVER, AND MAY DROP CLOSE TO  
FREEZING FOR MORE SENSITIVE AREAS OF THE DESERT SOUTHWEST AND THE  
CENTRAL CALIFORNIA VALLEYS.   
  
ELSEWHERE, SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS  
FLORIDA. BANDS OF HEAVY LAKE EFFECT SNOW WILL CONTINUE THE NEXT  
COUPLE OF DAYS FOR FAVORABLE DOWNWIND LOCATIONS OF THE GREAT LAKES  
WITH PERSISTENT NORTHWESTERLY FLOW IN PLACE. A CLIPPER SYSTEM  
DROPPING SOUTH FROM CANADA INTO THE NORTHERN PLAINS AND UPPER  
MIDWEST WILL BRING SOME SNOW SHOWERS THROUGH MID-WEEK.  
  
PUTNAM  
  
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
  
 
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