083  
FXUS02 KWBC 050642  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
141 AM EST WED JAN 5 2022  
 
VALID 12Z SAT JAN 8 2022 - 12Z WED JAN 12 2022  
   
..GENERAL PATTERN OVERVIEW
 
 
AN AMPLIFIED BUT PROGRESSIVE UPPER LEVEL PATTERN IS EXPECTED TO BE  
IN PLACE THROUGH EARLY NEXT WEEK WITH A DEEP TROUGH TRACKING FROM  
THE ROCKIES TO THE EAST COAST, AND A RIDGE AXIS MOVING INTO THE  
WESTERN U.S. FROM THE EASTERN PACIFIC. BY NEXT WEDNESDAY A SECOND  
TROUGH MOVES ACROSS THE PLAINS AND A STORM SYSTEM BEGINS  
APPROACHING THE PACIFIC NORTHWEST, WITH MORE OF A QUASI-ZONAL FLOW  
PATTERN OVER THE EASTERN U.S. AS THE EARLIER TROUGH DEPARTS.  
   
..GUIDANCE/PREDICTABILITY ASSESSMENT
 
 
THE 00Z MODEL GUIDANCE SUITE AND ENSEMBLES CONTINUE TO AGREE QUITE  
WELL ON THE OVERALL SYNOPTIC SCALE PATTERN, PARTICULARLY THROUGH  
THE UPCOMING WEEKEND. GOING IN EARLY NEXT WEEK, THE MODELS STILL  
HAVE A GOOD HANDLE ON THE DEEP TROUGH OVER THE EAST COAST REGION  
AND THE TIMING OF THE COLD FRONT PASSAGE. HOWEVER, MODEL  
DIFFERENCES ARE MORE APPARENT FOR THE WESTERN U.S. AS A SPLIT FLOW  
ALOFT LIKELY DEVELOPS. TIMING DIFFERENCES EXIST AMONG THE  
CMC/ECMWF/GFS WITH NORTHERN STREAM ENERGY APPROACHING THE PACIFIC  
NORTHWEST, AND LATITUDINAL DIFFERENCES WITH A POTENTIAL CLOSED LOW  
NEAR SOUTHERN CALIFORNIA. BY WEDNESDAY, THE GFS IS FASTER WITH  
THIS SHORTWAVE ENERGY IN THE NORTHERN STREAM ACROSS THE GREAT  
LAKES AND OHIO VALLEY, COMPARED TO THE SLOWER CMC/ECMWF GUIDANCE.  
 
THE WPC FORECAST WAS BASED PRIMARILY ON A MULTI-DETERMINISTIC  
MODEL BLEND THROUGH SUNDAY, AND THEN GRADUALLY INCREASING USE OF  
THE ECENS AND GEFS MEANS THROUGH EARLY NEXT WEEK WHILE STILL  
KEEPING ABOUT 50 PERCENT OF A CMC/ECMWF/GFS BLEND..  
   
..HAZARDS/SENSIBLE WEATHER HIGHLIGHTS
 
 
GULF MOISTURE ADVECTING NORTHWARD AHEAD OF A DEVELOPING  
PLAINS/MIDWEST COLD FRONT IS EXPECTED TO RESULT IN INCREASING  
COVERAGE OF SHOWERS AND THUNDERSTORMS FROM EASTERN TEXAS AND THE  
CENTRAL GULF COAST, TO THE OHIO VALLEY AND MID-ATLANTIC REGION  
THIS WEEKEND, WITH LIGHTER RAINFALL EXPECTED FARTHER NORTH. THERE  
WILL LIKELY BE SOME EMBEDDED HEAVIER RAINFALL ACROSS PORTIONS OF  
THE DEEP SOUTH WHERE CONVECTION IS PERSISTENT. AREAS FROM THE  
UPPER GREAT LAKES TO THE NORTHEAST COULD SEE WINTRY WEATHER, WITH  
THE BEST SNOWFALL PROSPECTS OVER NORTHERN NEW ENGLAND AND NORTHERN  
NEW YORK. PARTS OF THE GREAT LAKES MAY SEE LAKE EFFECT SNOW  
BEHIND THE PASSING FRONT. GOING INTO NEXT WEEK, DRY CONDITIONS  
ARE EXPECTED ACROSS MOST OF THE NATION EXCEPT FOR SOME SHOWERS AND  
MOUNTAIN SNOW OVER WESTERN WASHINGTON AND OREGON ASSOCIATED WITH  
THE NEXT STORM SYSTEM.  
 
SOME MODERATION OF THE SEVERE COLD OVER THE PLAINS/MIDWEST IS  
EXPECTED ON SATURDAY AHEAD OF THE NEXT ARCTIC SURGE THAT REACHES  
INTO THE NORTHERN TIER STATES BY SUNDAY AND INTO MONDAY. THE  
SECOND SURGE MAY NOT BE QUITE AS INTENSE AS WHAT IS EXPECTED FOR  
THE END OF THIS WEEK, BUT TEMPERATURES COULD STILL BE 10-25F BELOW  
NORMAL FROM EASTERN MONTANA TO WISCONSIN. FROM SATURDAY INTO  
SUNDAY, ABOVE NORMAL TEMPERATURES WILL PROGRESS FROM THE SOUTHERN  
PLAINS TO THE DEEP SOUTH AND SOUTHEAST U.S., WITH OVERNIGHT LOWS  
ON THE ORDER OF 15-25 DEGREES ABOVE NORMAL ACROSS THE CENTRAL GULF  
COAST REGION SUNDAY MORNING. SEASONABLY COLD CONDITIONS ARE  
LIKELY WEST OF THE CONTINENTAL DIVIDE WITH READINGS GENERALLY  
WITHIN 10 DEGREES OF CLIMATOLOGICAL AVERAGES, AND 10-20 DEGREES  
BELOW NORMAL FOR THE EAST COAST BY NEXT TUESDAY.  
 
HAMRICK  
 
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, WINTER WEATHER OUTLOOK PROBABILITIES  
AND HEAT INDICES ARE AT:  
 
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/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML  
 

 
 

 
 
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