156  
FXUS01 KWBC 150821  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 AM EST SAT FEB 15 2025  
 
VALID 12Z SAT FEB 15 2025 - 12Z MON FEB 17 2025  
 
...A LIFE-THREATENING FLASH FLOODING EVENT EMERGING OVER THE LOWER  
TO MID-MISSISSIPPI, TENNESSEE AND OHIO VALLEYS INTO PARTS OF THE  
APPALACHIANS WITH SEVERE THUNDERSTORMS ACROSS THE DEEP SOUTH...  
 
...WIDESPREAD MODERATE TO LOCALLY HEAVY SNOWFALL ALONG WITH  
INCREASING WINDS FROM THE UPPER MIDWEST THROUGH THE GREAT LAKES  
AND NEW ENGLAND THIS WEEKEND WITH A SWATH OF SLEET/ICE JUST TO THE  
SOUTH...  
 
...ANOTHER SURGE OF ARCTIC AIR WILL SPREAD SOUTHWARD ACROSS THE  
NORTHERN U.S. THIS WEEKEND INTO EARLY NEXT WEEK WITH SNOW  
DEVELOPING FROM THE NORTHERN ROCKIES INTO THE NORTH-CENTRAL  
PLAINS...  
 
...PACIFIC SYSTEM WILL BRING RENEWED ROUND OF LOWER ELEVATION  
COASTAL/VALLEY RAIN AND HIGHER ELEVATION SNOW TO THE PACIFIC  
NORTHWEST BY SUNDAY...  
 
AS A LOW PRESSURE SYSTEM EXITS THE WESTERN U.S. AND MOVES INTO THE  
CENTRAL PLAINS EARLY THIS MORNING, A HIGH PRESSURE SYSTEM  
ASSOCIATED WITH A LARGE POOL OF ARCTIC AIR IN CANADA IS POISED TO  
SURGE SOUTHWARD INTO THE PLAINS. THE INTERACTION BETWEEN THE TWO  
SYSTEMS WILL RESULT IN A RATHER LARGE CYCLONE TO DEVELOP AND  
INTENSIFY AS IT TRACKS FROM SOUTHWEST TO NORTHEAST ACROSS THE  
EASTERN HALF OF THE COUNTRY THROUGH THE NEXT COUPLE OF DAYS, WHERE  
WIDESPREAD IMPACTFUL TO LOCALLY LIFE-THREATENING WEATHER IS  
EXPECTED IN THE PATH OF THIS CYCLONE. OF IMMEDIATE CONCERN IS A  
LIFE-THREATENING FLASH FLOODING EVENT CURRENTLY DEVELOPING FROM  
THE LOWER TO MID-MISSISSIPPI INTO THE TENNESSEE VALLEYS, AND  
GRADUALLY SPREADING INTO THE OHIO VALLEY. THE COMBINATION OF  
FAVORABLY STRONG DYNAMICS INTERACTING WITH PLENTIFUL MOISTURE  
ALONG A WARM FRONT WILL CONTRIBUTE TO WIDESPREAD INTENSE  
THUNDERSTORMS INCREASING IN COVERAGE ACROSS THESE AREAS THROUGH  
THE DAY. REPEATED ROUNDS OF INTENSE STORMS WILL LEAD TO RAINFALL  
RATES OF 1-2" PER HOUR AND TOTALS OF 3-6", WITH ISOLATED AMOUNTS  
UP TO 8" AS THE STORMS MOVE PARALLEL TO AND BACK BUILD ALONG THE  
FRONT. THE GREATEST RISK FOR THIS INTENSE RAINFALL PROMPTING  
LIFE-THREATENING FLASH FLOODING WILL BE ACROSS PORTIONS OF  
NORTHWESTERN TENNESSEE AND WESTERN KENTUCKY, WHERE A HIGH RISK OF  
EXCESSIVE RAINFALL (LEVEL 4/4) IS IN EFFECT. A BROADER MODERATE  
RISK (LEVEL 3/4) COVERS PORTIONS OF THE MID-SOUTH TO OHIO VALLEY,  
WITH A SLIGHT RISK (LEVEL 2/4) ENCOMPASSING THE GENERAL REGION  
EAST TO THE APPALACHIANS. STILL POTENTIALLY SIGNIFICANT, BUT MORE  
SCATTERED INSTANCES OF FLASH FLOODING WILL BE POSSIBLE IN THESE  
AREAS. IN ADDITION TO THE FLOOD RISK, SEVERE WEATHER IS ALSO  
EXPECTED, WITH AN ENHANCED RISK (LEVEL 3/5) ISSUED BY THE STORM  
PREDICTION CENTER FOR PORTIONS OF THE LOWER MISSISSIPPI VALLEY.  
SUPERCELL THUNDERSTORMS AHEAD OF THE FRONT WILL BE CAPABLE OF ALL  
SEVERE HAZARDS TODAY, INCLUDING THE RISK FOR STRONG TORNADOES. THE  
PROGRESS OF A POTENT COLD FRONT WILL SPEED UP ACROSS THE SOUTH  
INTO THIS EVENING, TRANSITIONING THE THREAT TO DAMAGING WINDS AND  
QLCS TORNADOES, WHICH MAY CONTINUE FURTHER EAST INTO THE SOUTHEAST  
OVERNIGHT SATURDAY. THE SYSTEM WILL CONTINUE EASTWARD ON SUNDAY,  
WITH A BROAD AREA OF SHOWERS AND THUNDERSTORMS SPREADING ACROSS  
THE MID-ATLANTIC AND SOUTHEAST PRODUCING MODERATE TO LOCALLY HEAVY  
RAINFALL, WITH SOME ISOLATED FLASH FLOODING POSSIBLE IN THE  
SOUTHERN MID-ATLANTIC.  
 
TO THE NORTH, A BAND OF MODERATE TO LOCALLY HEAVY SNOW IS QUICKLY  
EXPANDING FROM THE UPPER MIDWEST INTO THE GREAT LAKES TODAY.  
WINTER WEATHER ADVISORIES ARE IN PLACE FOR TOTALS GENERALLY IN THE  
3-6" RANGE. A WINTRY MIX WILL BE POSSIBLE IN THE TRANSITION ZONE  
ALONG THE STORM TRACK THROUGH PORTIONS OF THE MIDWEST. AS THE  
STORM INTENSIFIES, A MORE SIGNIFICANT WINTER STORM IS BECOMING  
LIKELY FOR UPSTATE NEW YORK AND NORTHERN NEW ENGLAND LATE TONIGHT  
INTO SUNDAY. INCREASINGLY STRONG AND GUSTY WINDS MAY ALSO LEAD TO  
PERIODS OF BLOWING SNOW AND VERY DIFFICULT TRAVEL CONDITIONS AS  
THE INTENSIFYING CYCLONE PASSES THROUGH. SOME MODERATE SNOW  
TOTALS WILL ALSO BE POSSIBLE FURTHER SOUTH ACROSS HIGHER  
ELEVATIONS OF THE APPALACHIANS. BY MONDAY MORNING, THE DEEP STORM  
WILL BEGIN TO MOVE EAST OF NEW ENGLAND WITH MUCH OF THE RAIN MOVED  
OFF THE EAST COAST AND THE SNOW TAPERING OFF IN NEW ENGLAND.  
HOWEVER, BLUSTERLY NORTHWESTERLY WINDS WILL USHER MUCH COLDER AIR  
INTO THE EASTERN U.S. WITH RE-NEWED ROUNDS OF LAKE-EFFECT SNOWS  
DOWNWIND FROM THE GREAT LAKES.  
 
DAYTIME HIGH TEMPERATURES WILL BE ABOVE AVERAGE AND RATHER MILD  
FOR REGIONS AHEAD OF THE STORM SYSTEM FROM THE CENTRAL TO EASTERN  
U.S. THIS WEEKEND. FORECAST HIGHS IN THE 50S TO 70S ARE EXPECTED  
FROM THE OHIO VALLEY SOUTHWARD TO THE LOWER MISSISSIPPI  
VALLEY/TEXAS/GULF COAST FOR TODAY. BY SUNDAY, MUCH WARMER  
TEMPERATURES ARE FORECAST ACROSS THE MID-ATLANTIC AND CAROLINAS AS  
TEMPERATURES REACH INTO THE 50S AND 60S HERE AS WELL, WITH 60S AND  
70S IN THE SOUTHEAST AHEAD OF THE FRONT. ARCTIC AIR FROM CANADA  
WILL THEN SPREAD SOUTHWARD BEHIND THE FRONT, BRINGING WELL BELOW  
AVERAGE, BITTERLY COLD TEMPERATURES TO AREAS OF THE NORTHERN AND  
CENTRAL PLAINS BEGINNING TODAY, WITH HIGHS IN THE SINGLE DIGITS  
AND TEENS FOR MANY LOCATIONS. SOME HIGHS MAY NOT EVEN REACH ABOVE  
ZERO BY SUNDAY. BY MONDAY MORNING, -30 DEGREES OR COLDER  
TEMPERATURES ARE POSSIBLE NEAR THE CANADIAN BORDER OF THE HIGH  
PLAINS. BLUSTERY WINDS WILL LEAD TO WIND CHILLS WELL BELOW ZERO,  
PARTICULARLY ACROSS THE NORTHERN PLAINS. THESE COLDER  
TEMPERATURES WILL EXPAND INTO THE MISSISSIPPI VALLEY AND SOUTHERN  
PLAINS BY SUNDAY WITH HIGHS DROPPING INTO THE 30S AND 40S FOR MOST  
LOCATIONS.  
 
BACK TO THE WEST, AN UPPER-LEVEL TROUGH/PACIFIC STORM SYSTEM WILL  
BRING A RENEWED ROUND OF PRECIPITATION TO THE PACIFIC NORTHWEST  
BEGINNING LATE SATURDAY WHICH WILL SPREAD INLAND ACROSS THE  
NORTHERN GREAT BASIN/ROCKIES INTO SUNDAY. THIS WILL INCLUDE  
PERIODS OF MODERATE RAINFALL FOR COASTAL LOCATIONS, A MIX OF RAIN  
AND SNOW FOR INTERIOR VALLEYS, AND MODERATE TO LOCALLY HEAVY SNOW  
ACCUMULATIONS FOR HIGHER MOUNTAIN ELEVATIONS, PARTICULARLY ACROSS  
THE CASCADES AND NORTHERN ROCKIES. BY SUNDAY NIGHT INTO MONDAY  
MORNING, MOISTURE FROM THE PACIFIC SYSTEM WILL BEGIN TO INTERACT  
WITH A STATIONARY ARCTIC FRONT TO EXPAND A SWATH OF ACCUMULATING  
SNOWFALL FROM THE NORTHERN ROCKIES TOWARD AND INTO THE NORTHERN  
PLAINS.  
 
KONG/PUTNAM  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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