295  
FXUS02 KWBC 081842  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
142 PM EST WED JAN 8 2025  
 
VALID 12Z SAT JAN 11 2025 - 12Z WED JAN 15 2025  
   
..OVERVIEW
 
 
A QUIETER WEATHER PATTERN IS ON TAP FOR THE WEEKEND INTO EARLY NEXT  
WEEK. BROAD MEAN UPPER TROUGHING WILL EXTEND FROM THE NORTHEAST TO  
THE SOUTHWEST, AND A SERIES OF UPPER LOWS WILL CHURN OVER  
SOUTHEASTERN CANADA, THE GREAT LAKES, AND THE FAR NORTHEAST. A FEW  
WEAK FRONTAL SYSTEM ARE FORECAST TO MOVE ACROSS THE EASTERN TWO  
THIRDS OF THE NATION, BUT PRECIPITATION CHANCES WILL BE FAIRLY  
LIMITED. THIS WEEKEND, PRECIPITATION CHANCES WILL FOCUS OVER THE  
NORTHERN ROCKIES AND PLAINS IN THE VICINITY OF LOW PRESSURE AND  
ALONG THE EAST COAST AS A STORM SYSTEM PUSHES OFFSHORE. EARLY NEXT  
WEEK, PRECIPITATION CHANCES WILL BE LIMITED TO THE GREAT LAKES  
WHERE LIGHT TO MODERATE LAKE EFFECT SNOWS WILL BE POSSIBLE. THIS  
PATTERN WILL CONTINUE BELOW NORMAL TEMPERATURES FOR MOST OF THE  
NATION, WITH HAZARDOUS COLD FOR SOME.  
 
   
..GUIDANCE/PREDICTABILITY ASSESSMENT
 
 
MODEL AND ENSEMBLE FORECAST SPREAD CONTINUES TO DECREASE, LEADING  
TO HIGHER FORECAST CONFIDENCE. THE MOST UNCERTAIN FEATURES IN THE  
FORECAST ARE WEAKER FEATURES EARLY-MID NEXT WEEK, WHICH ARE HARDER  
FOR THE MODELS TO RESOLVE. HOWEVER, THE AFFECT ON THE SENSIBLE  
WEATHER SHOULD BE MINIMAL SINCE THESE FEATURES ARE NOT FORECAST TO  
PRODUCE SIGNIFICANT WEATHER HAZARDS.  
 
WPC'S AFTERNOON FORECAST WAS DERIVED FROM A GENERAL BLEND OF THE  
AVAILABLE MODEL GUIDANCE INCLUDING THE GFS/ECMWF/CMC/UKMET AND  
NATIONAL BLEND OF MODELS, WHICH PRODUCED A REASONABLY GOOD  
FORECAST GIVEN LITTLE MODEL SPREAD. ENSEMBLE MEANS FROM THE  
GEFS/ECENS/CMCE WERE ADDED TO THE BLEND EARLY-MID NEXT WEEK TO HELP  
SMOOTH OUT MINOR DIFFERENCES IN THE DETERMINISTIC MODEL GUIDANCE.  
 
   
..WEATHER/HAZARDS HIGHLIGHTS
 
 
THE WINTER STORM SET TO SLAM THE SOUTHERN U.S. LATE THIS WEEK WILL  
BE MOVING OFFSHORE BY SATURDAY. WINTRY WEATHER WILL LINGER ACROSS  
THE MID-ATLANTIC AND NORTHEAST ON SATURDAY AS THE SYSTEM  
STRENGTHENS OFFSHORE, AND LIGHT TO MODERATE WINTRY PRECIPITATION  
COULD CREATE LOCALLY HAZARDOUS CONDITIONS, ESPECIALLY WHERE SNOW  
MAY BE ENHANCED IN THE CENTRAL/NORTHERN APPALACHIANS AND DOWNWIND  
OF THE EASTERN GREAT LAKES. AN ANOMALOUSLY COLD AIR MASS WILL  
REMAIN IN PLACE OVER THE SOUTH, SOUTHEAST, AND MID-ATLANTIC THROUGH  
THE WEEKEND, AND TRAILING FRONTS MAY CONTINUE TO FOCUS PERIODIC  
RAIN/CONVECTION BACK ACROSS FLORIDA, THE NORTHERN GULF OF MEXICO,  
AND SOUTHERN TEXAS THROUGH EARLY-MID NEXT WEEK.  
 
WINTRY WEATHER IS ALSO EXPECTED FROM THE NORTHWEST TO THE PLAINS  
THIS WEEKEND AS A FRONTAL SYSTEM TRACKS EAST. THIS SYSTEM WILL  
PUSH TOWARDS THE MIDWEST AND GREAT LAKES EARLY NEXT WEEK, LIKELY  
TRIGGERING ADDITIONAL LAKE EFFECT SNOWS. IN THE WAKE OF THIS  
SYSTEM, ANOTHER BLAST OF ARCTIC AIR IS FORECAST TO SPILL INTO THE  
NORTH-CENTRAL U.S. THIS WEEKEND AND SPREAD TO THE EAST AND  
SOUTHEAST NEXT WEEK. HAZARDOUS COLD TEMPERATURES ARE EXPECTED FROM  
THE NORTHERN PLAINS TO THE GULF AND SOUTHEAST COASTS, WITH  
TEMPERATURE ANOMALIES POTENTIALLY REACHING 10-20 DEGREES BELOW  
NORMAL.  
 
ELSEWHERE, HIGH PRESSURE WILL DOMINATE IN THE WEST EARLY NEXT WEEK  
AND SPREAD ACROSS THE SOUTH BY MID-WEEK. TEMPERATURES UNDERNEATH  
THIS AREA OF HIGH PRESSURE WILL LIKELY BE NEAR TO SLIGHTLY BELOW  
NORMAL.  
 
DOLAN  
 
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC  
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION FORECAST (QPF), EXCESSIVE RAINFALL  
OUTLOOK (ERO), WINTER WEATHER OUTLOOK (WWO) PROBABILITIES, HEAT  
INDICES, AND KEY MESSAGES CAN BE ACCESSED FROM:  
 
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=ERO  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW  
 

 
 
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