040  
FXUS01 KWBC 310757  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
255 AM EST FRI JAN 31 2025  
 
VALID 12Z FRI JAN 31 2025 - 12Z SUN FEB 02 2025  
 
...PRECIPITATION RETURNS TO THE WEST COAST, WITH ATMOSPHERIC RIVER  
ACTIVITY EXPECTED TO BRING HEAVY RAIN AND FLOODING CONCERNS TO  
PORTIONS OF CENTRAL AND NORTHERN CALIFORNIA...  
 
...MUCH NEEDED RAINFALL EXPECTED ACROSS THE UPPER TENNESSEE  
VALLEY, SOUTHERN APPALACHIANS AND MID-ATLANTIC, WITH LIGHT WINTRY  
PRECIPITATION EXPECTED FOR NEW ENGLAND...  
 
...ABOVE AVERAGE TEMPERATURES ARE EXPECTED ACROSS LARGE SECTIONS  
OF THE COUNTRY GOING INTO THE WEEKEND WITH EXCEPTION TO THE  
NORTHWEST AND THE NORTHEAST WHERE TEMPERATURES WILL BE TRENDING  
GRADUALLY BELOW NORMAL...  
 
AFTER SEVERAL WEEKS OF NO PRECIPITATION ALONG LARGE PORTIONS OF  
THE WEST COAST, A CONSIDERABLY MORE ACTIVE WEST COAST WEATHER  
PATTERN WILL UNFOLD OVER THE NEXT FEW DAYS WHICH WILL INCLUDE THE  
ARRIVAL OF MULTIPLE PACIFIC FRONTAL SYSTEMS. THIS WILL INCLUDE THE  
ARRIVAL AGAIN OF WELL-DEFINED ATMOSPHERIC RIVER ACTIVITY ALSO INTO  
ESPECIALLY CENTRAL AND NORTHERN CALIFORNIA. MUCH OF THE RAIN AND  
HIGHER ELEVATION SNOWFALL WILL BE WELCOMED ACROSS THE PACIFIC  
NORTHWEST, BUT FOR CALIFORNIA, THE CONCERN ESPECIALLY BY SATURDAY  
AND SUNDAY WILL BE HEAVY TO EXCESSIVE RAINFALL THAT WILL LEAD TO  
FLOODING CONCERNS. THIS WILL INCLUDE THE BAY AREA AND INTERIOR  
AREAS OF THE SACRAMENTO VALLEY AND ALSO THE FOOTHILLS OF THE  
SIERRA NEVADA. A SLIGHT RISK (LEVEL 2 OF 4) OF EXCESSIVE RAINFALL  
HAS BEEN DEPICTED BY THE WEATHER PREDICTION CENTER ACROSS THESE  
AREAS, AND WHILE THERE WILL BE CERTAINLY BENEFITS TO THE RAINFALL,  
THE EXPECTATION IS THAT A FRONT WILL STALL OUT ACROSS CENTRAL  
CALIFORNIA AND FOSTER A PERSISTENCE OF ATMOSPHERIC RIVER  
CONDITIONS AND HEAVY RAINS THAT WILL DRIVE FLOODING CONCERNS.  
TEMPERATURES ACROSS THE WEST WILL INITIALLY BE ABOVE NORMAL FOR  
MANY LOCATIONS, BUT THE PASSAGE OF THE FRONTAL ACTIVITY OVER THE  
PACIFIC NORTHWEST SHOULD ALLOW TEMPERATURES HERE TO TREND  
GRADUALLY BELOW NORMAL, AND THIS WILL ALSO ALLOW FOR LOWERING SNOW  
LEVELS IN TIME.  
 
MEANWHILE, A STORM SYSTEM CROSSING THROUGH THE OHIO AND TENNESSEE  
VALLEYS WILL BE ADVANCING ACROSS THE CENTRAL AND SOUTHERN  
APPALACHIANS AND THE MID-ATLANTIC STATES TODAY THROUGH TONIGHT  
WHICH WILL BRING MODERATE TO LOCALLY HEAVY RAINFALL. GENERALLY  
THESE RAINS WILL BE QUITE BENEFICIAL, BUT THERE MAY BE SUFFICIENT  
RAINFALL IN CONJUNCTION WITH SNOWMELT OVER THE HIGHER TERRAIN OF  
THE CENTRAL APPALACHIANS TO BRING A THREAT OF FLOODING. A SLIGHT  
RISK (LEVEL 2 OF 4) OF EXCESSIVE RAINFALL HAS BEEN DEPICTED ACROSS  
THE HIGHER TERRAIN OF WEST VIRGINIA. A PORTION OF THIS STORM  
SYSTEM WILL ALSO BRING HEAVY TO POTENTIALLY EXCESSIVE RAINFALL  
TODAY ACROSS AREAS OF NORTHERN ILLINOIS. HOWEVER, THE NORTHERN  
EDGE OF THE PRECIPITATION SHIELD AS IT LIFTS OFF TO THE NORTHEAST  
INTO PARTS OF NEW YORK AND NEW ENGLAND WILL ENCOUNTER A SUFFICIENT  
AMOUNT OF COLD AIR FOR SOME LIGHT SNOWFALL AND ALSO LOCALLY SOME  
CONCERNS FOR SLEET AND FREEZING RAIN. THIS STORM SYSTEM WILL EXIT  
THE REGION BY EARLY THIS WEEKEND, WITH COLDER TEMPERATURES  
ARRIVING IN ITS WAKE AND ESPECIALLY ACROSS THE NORTHEAST.  
 
BY SUNDAY, A NEW STORM SYSTEM RELATED TO THE UNSETTLED WEATHER  
IMPACTING THE WEST COAST WILL BEGIN TO EJECT EAST OUT ACROSS THE  
NORTHERN PLAINS, AND THIS WILL BRING A THREAT FOR SEVERAL INCHES  
OF ACCUMULATING SNOW TO THE UPPER MIDWEST. COLDER TEMPERATURES  
WILL BEGIN TO SETTLE SOUTH FROM CANADA IN THE WAKE OF THIS SYSTEM  
ACROSS THE NORTHERN HIGH PLAINS. HOWEVER, ABOVE AVERAGE  
TEMPERATURES THOUGH ARE EXPECTED IN GENERAL ACROSS MUCH OF THE  
COUNTRY OUTSIDE OF THE NORTHWEST AND THE NORTHEAST, AND IN SOME  
CASES ACROSS THE PLAINS AND MIDWEST, THE TEMPERATURES THIS WEEKEND  
WILL BE AS MUCH AS 15 TO 20 DEGREES ABOVE NORMAL. MANY AREAS OF  
THE SOUTHEAST AND THE SOUTHWEST WILL ALSO BE WARMER THAN NORMAL  
WITH HIGHS AS MUCH AS AVERAGE 5 TO 10+ DEGREES ABOVE AVERAGE.  
 
ORRISON  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 
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