715  
FXUS02 KWBC 040656  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
154 AM EST TUE JAN 4 2022  
 
VALID 12Z FRI JAN 7 2022 - 12Z TUE JAN 11 2022  
   
..GENERAL PATTERN OVERVIEW
 
 
THE UPPER LEVEL PATTERN OVER THE CONTINENTAL U.S. THROUGH THE  
BEGINNING OF NEXT WEEK SHOULD REMAIN FAIRLY AMPLIFIED BUT ALSO  
PROGRESSIVE. A STRONG SHORTWAVE TROUGH AND ASSOCIATED NOR'EASTER  
WILL EXIT THE EAST COAST FRIDAY, AND THIS SHOULD GIVE WAY TO A  
CANADIAN SURFACE HIGH AND COLD WEATHER SETTLING ACROSS THE  
EAST-CENTRAL U.S. IN THE WAKE OF THE STRONG COLD FRONT. BY THE  
WEEKEND, ANOTHER COLD FRONT CROSSES THE PLAINS WITH A RENEWED  
SURGE OF ARCTIC AIR FOR THE NORTH-CENTRAL U.S., AND A SURGE OF  
MOISTURE AHEAD OF IT ACROSS THE GULF COAST REGION. UPPER LEVEL  
RIDGING SETS IN ACROSS THE WEST BY EARLY NEXT WEEK.  
 
   
..GUIDANCE ASSESSMENT AND UNCERTAINTY
 
 
THE 00Z MODEL GUIDANCE SUITE IS IN VERY GOOD SYNOPTIC SCALE  
AGREEMENT THROUGH THE WEEKEND WITH SOME MESOSCALE TIMING AND  
AMPLITUDE DIFFERENCES WITH THE INDIVIDUAL SHORTWAVE PASSAGES. THE  
GFS IS SLIGHTLY MORE AMPLIFIED WITH THE TROUGH ORIGINATING FROM  
THE WEST COAST SATURDAY AS IT TRACKS EASTWARD ACROSS THE PLAINS  
SUNDAY, AND ALSO A BIT MORE POTENT WITH A NORTHERN STREAM  
SHORTWAVE DROPPING SOUTH FROM THE HUDSON BAY REGION LATE ON  
MONDAY, ALTHOUGH EXCELLENT AGREEMENT WITH THE LARGE SCALE TROUGH  
EXPECTED TO BE OVER THE EAST BY THAT TIME. THERE ARE ALSO SOME  
MODEST DIFFERENCES WITH A SOUTHERN STREAM CLOSED LOW NEAR SOUTHERN  
CALIFORNIA, BUT CLOSE ENOUGH TO SUPPORT A GENERAL MODEL BLEND.  
 
THE WPC FORECAST WAS BASED PRIMARILY ON A MULTI-DETERMINISTIC  
MODEL BLEND THROUGH SATURDAY, AND THEN GRADUALLY INCREASING USE OF  
THE ECENS AND GEFS MEANS THROUGH EARLY NEXT WEEK.  
 
   
..SENSIBLE WEATHER
 
 
AFTER AN ACTIVE PERIOD OF WEATHER DURING THE SHORT RANGE PERIOD  
ACROSS THE PACIFIC NORTHWEST, SOME LINGERING RAIN AND MOUNTAIN  
SNOW IS STILL LIKELY FROM NORTHERN CALIFORNIA TO WESTERN  
WASHINGTON, AND SNOW FOR THE NORTHERN ROCKIES, ON FRIDAY. A  
DRYING TREND SHOULD COMMENCE IN TIME FOR THE WEEKEND ACROSS MUCH  
OF THE WEST AS HIGH PRESSURE BUILDS BACK INTO THE REGION.  
MEANWHILE, AN INTENSIFYING NOR'EASTER OFF THE NEW ENGLAND COAST  
MAY STILL PRODUCE SOME LINGERING SNOW SHOWERS FOR MUCH OF THE  
NORTHEAST STATES, WITH THE HEAVIEST QPF LIKELY OFFSHORE BY FRIDAY  
MORNING. MORE SHOWERS AND STORMS ARE LIKELY TO MAKE A RETURN TO  
THE GULF COAST REGION AND INTO THE TENNESSEE VALLEY BY SUNDAY  
AHEAD OF THE NEXT FRONT.  
 
TEMPERATURES ARE EXPECTED TO BE QUITE COLD ACROSS THE  
CENTRAL/NORTHERN PLAINS TO THE UPPER MIDWEST THROUGH THE END OF  
THE WEEK WITH A LARGE SURFACE HIGH OF ARCTIC ORIGIN GOVERNING THE  
WEATHER PATTERN FOR THIS REGION. HIGHS IN THE TEENS SETTLING AS  
FAR SOUTH AS CENTRAL INDIANA AND ILLINOIS ARE LIKELY ON FRIDAY.  
SOME MODERATION OF THE SEVERE COLD MAY COME ACROSS THIS REGION ON  
SATURDAY AHEAD OF THE NEXT ARCTIC SURGE INTO THE NORTHERN TIER  
STATES ON SUNDAY, WHICH IS NOT EXPECTED TO BE QUITE AS INTENSE AS  
THE EARLIER ARCTIC BLAST. ELSEWHERE, SEASONABLY COLD CONDITIONS  
ARE EXPECTED WEST OF THE CONTINENTAL DIVIDE WITH READINGS  
GENERALLY WITHIN 10 DEGREES OF CLIMATOLOGICAL AVERAGES, AND MILD  
ACROSS THE SOUTHERN PLAINS AND DEEP SOUTH WITH HIGHS RUNNING 5 TO  
15 DEGREES ABOVE AVERAGE THIS WEEKEND.  
 
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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