208  
FXUS02 KWBC 081901  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
200 PM EST SAT JAN 08 2022  
 
VALID 12Z TUE JAN 11 2022 - 12Z SAT JAN 15 2022  
   
..OVERVIEW
 
 
MODEL GUIDANCE INDICATES THAT GENERAL RIDGING WILL PREVAIL OVER  
THE WESTERN U.S. AS BROAD TROUGHING TENDS TO EJECT DISTURBANCES  
EASTWARD ACROSS THE NORTHERN TIERS AS WELL AS THE DEEP SOUTH UNDER  
A SPLIT FLOW PATTERN. MEANWHILE, A CLOSED UPPER LOW LINGERING  
JUST OFF THE SOUTHWEST WILL LIKELY PLAY A ROLE IN BRINGING GULF  
MOISTURE INTO THE SOUTH LATE NEXT WEEK. HEAVY PRECIPITATION WILL  
EDGE CLOSER TOWARD THE PACIFIC NORTHWEST TUE/WED BUT WITH THE  
HEAVIEST ACTIVITIES LIKELY OVER VANCOUVER ISLAND.  
   
..GUIDANCE/PREDICTABILITY ASSESSMENT
 
 
OVERALL, MODELS SHOW REASONABLY GOOD AGREEMENT IN PREDICTING THE  
PATTERN EVOLUTION ACROSS THE U.S. FOR THE MEDIUM-RANGE PERIOD,  
WITH EXPECTED LARGE SPREAD TOWARD THE END OF NEXT WEEK. THE MAIN  
ISSUES ARE WITH REGARD TO HOW THE LINGERING UPPER LOW OFF THE  
SOUTHWEST SHOULD BE HANDLED, AS WELL AS THE SPEED AND AMPLITUDE OF  
THE NEXT PACIFIC TROUGH/UPPER LOW SHOULD APPROACH THE WEST COAST  
DURING THE LATTER HALF OF NEXT WEEK. FARTHER EAST, THERE IS  
UNCERTAINTY WITH REGARD TO THE SPEED OF THE NORTHERN STREAM  
DISTURBANCES AS WELL AS HOW MUCH THEY PHASE WITH THE SOUTHERN  
STREAM ENERGY. IT APPEARS THAT THE LATEST ENSEMBLE MEANS FAVOR  
MORE PHASING OF THE TWO STREAMS WITH A COUPLE OF LOW PRESSURE  
SYSTEM TRACKING THROUGH THE NORTHERN TIER STATES AND THE DEEP  
SOUTH BY NEXT WEEKEND.  
 
A MULTI-MODEL/ENSEMBLE BLEND WAS USED TO COMPOSE THIS MORNING'S  
WPC MEDIUM-RANGE FORECASTS. THE 06Z GFS WAS NOTED TO DIVE TOO  
MUCH SHORTWAVE ENERGY ACROSS THE MIDWEST TOWARD THE SOUTHEAST NEXT  
THU-FRI. IT WAS ALSO TOO SLOW BRINGING IN THE UPPER LOW ACROSS  
THE SOUTHWEST LATE NEXT WEEK COMPARED WITH THE REST OF THE  
GUIDANCE. THE 00Z AND 12Z GFS WERE MORE AGREEABLE IN THIS REGARD.  
THE 00Z CMC WAS TOO AGGRESSIVE IN TRACKING A FRONTAL WAVE  
NEAR/NORTH OF THE GREAT LAKES BY DAY 5 IN CONTRADICTION WITH ITS  
ENSEMBLE MEANS. THE ECMWF REMAINS QUITE REASONABLE WITH ITS  
ENSEMBLE MEANS THROUGH DAY 7. THEREFORE, LITTLE TO NONE OF THE  
06Z GFS AND 00Z CMC WERE INCLUDED IN THE BLEND BEYOND DAY 5, WITH  
THE REMAINING PORTION FROM THE 00Z ECMWF/00Z EC MEAN AND THE 06Z  
GEFS, AND THE 00Z CMC MEAN.  
   
..WEATHER HIGHLIGHTS
 
 
THE PACIFIC NORTHWEST SHOULD SEE HEAVY PRECIPITATION EDGING CLOSER  
AHEAD OF A WARM FRONT TUE/WED, WITH HIGHER TOTALS OVER TYPICAL  
UPSLOPE AREAS OF THE OLYMPICS AND CASCADES BUT THE HEAVIEST  
ACTIVITIES LIKELY OVER VANCOUVER ISLAND. IN CONTRAST, DRY  
CONDITIONS WILL A CONTINUED WARMING TREND WILL LIKELY ENGULF MUCH  
OF THE CENTRAL AND NORTHERN PLAINS. A LARGE SURFACE HIGH WILL  
ALSO MAINTAIN DRY CONDITIONS OVER THE INTERMOUNTAIN WEST.  
MEANWHILE, A CLOSED UPPER LOW LINGERING JUST OFF THE SOUTHWEST  
WILL LIKELY MOVE INLAND AND PLAY A ROLE IN BRINGING GULF MOISTURE  
INTO THE SOUTH LATE NEXT WEEK.  
 
COLD AIR WILL BE IN PLACE OVER THE UPPER MIDWEST AND SPREADING  
INTO THE NORTHEAST ON TUESDAY, WITH HIGH TEMPERATURES 10-30F BELOW  
AVERAGE FOR ONE OF THE COLDEST DAYS OF THE SEASON THUS FAR. THEN  
THE CENTRAL U.S. WILL SEE A PRONOUNCED WARMING TREND NEXT WEEK  
WITH EXPANDING COVERAGE OF MAX/MIN TEMPERATURES 10-20F ABOVE  
NORMAL TUESDAY ONWARD. SOME LOCATIONS IN THE NORTHERN TWO-THIRDS  
OF THE PLAINS MAY SEE EVEN WARMER READINGS MID-LATE WEEK. ACROSS  
THE WEST EXPECT TO SEE DAYTIME HIGHS WITHIN 10F ON EITHER SIDE OF  
NORMAL THROUGH THE PERIOD, WHILE ABOVE NORMAL LOWS SHOULD BECOME  
MORE PREVALENT WITH TIME. BY THE END OF THE WEEK TEMPERATURES ARE  
CURRENTLY FORECAST TO MODERATE CLOSE TO NORMAL.  
 
KONG  
 
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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