168  
FXUS02 KWBC 191829  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
128 PM EST WED JAN 19 2022  
 
VALID 12Z SAT JAN 22 2022 - 12Z WED JAN 26 2022  
 
18Z UPDATE: THE OVERALL TREND IN THE 12Z MODEL GUIDANCE SUITE IS  
FOR A FASTER AND SLIGHTLY MORE SUPPRESSED SURFACE LOW THAT TRACKS  
OUT TO SEA BY SATURDAY MORNING, WITH ANY LINGERING PRECIPITATION  
COMING TO AN END ACROSS THE COASTAL MID-ATLANTIC BY MID-DAY  
SATURDAY. THERE IS NO INDICATION THAT THIS STORM WILL HAVE ANY  
SIGNIFICANT IMPACTS FOR THE NORTHEAST U.S. AT THIS TIME. FOR THE  
CLOSED LOW THAT EJECTS FROM THE SOUTHWEST TO THE GULF COAST  
REGION, THE CMC IS ON THE FAST SIDE OF THE MODEL GUIDANCE WITH THE  
ARRIVAL OF THE TROUGH TO THE NORTHERN GULF EARLY NEXT WEEK, AND  
THERE HAS BEEN A GRADUAL INCREASE IN THE QPF EXPECTED FROM THE  
ASSOCIATED LOW THAT DEVELOPS ALONG THE FRONT ACROSS THE CENTRAL  
AND WESTERN GULF COAST REGION. BY THE END OF THE FORECAST PERIOD,  
THIS STORM SYSTEM WILL LIKELY HEAD EAST ACROSS FLORIDA AND THEN  
OUT TO SEA. THE WPC FRONTS/PRESSURES FORECAST WAS PRIMARILY  
DERIVED FROM A MULTI-DETERMINISTIC BLEND THROUGH EARLY MONDAY, AND  
THEN INCORPORATED SOME OF THE NAEFS/ECENS FOR DAYS 6 AND 7. THE  
REST OF THE FORECAST REMAINS ON TRACK AND THE PREVIOUS FORECAST  
DISCUSSION IS APPENDED BELOW FOR REFERENCE. /HAMRICK  
______________________________  
   
..PATTERN OVERVIEW AND GUIDANCE/PREDICTABILITY ASSESSMENT
 
 
GUIDANCE REMAINS IN GOOD AGREEMENT WITH THE MEAN FLOW OVER THE  
LOWER 48 HIGHLIGHTED BY AN AMPLIFIED UPPER RIDGE OFF/ALONG THE  
WEST COAST AND AN AMPLIFIED AND UNSETTLING UPPER TROUGH OVER THE  
CENTRAL TO EASTERN U.S. THAT COINCIDES WITH SEVERAL SHORT AND  
MEDIUM RANGE ARCTIC BLASTS WITH PERIODS OF MUCH BELOW NORMAL  
TEMPERATURES. THE MODELS HAVE BEEN LESS THAN STELLAR WITH THE RUN  
TO RUN CONTINUITY OF EMBEDDED SHORTWAVES ROTATING THROUGH THE MEAN  
UPPER TROUGH POSITION AND SURFACE SYSTEM REFLECTION, BUT SEEM TO  
BE SLOWLY IMPROVING. GIVEN LINGERING MODEL VARIANCE ISSUES  
HOWEVER, THE EARLIER RELEASED WPC MEDIUM RANGE PRODUCT SUITE WAS  
PRIMARILY DERIVED FROM THE 12 UTC GEFS MEAN AND ESPECIALLY THE  
ECMWF ENSEMBLE MEAN ALONG WITH THE 01 UTC NATIONAL BLEND OF  
MODELS. THE 00 UTC MODELS SEEM TO BE CONVERGING ON BETTER  
CLUSTERED SOLUTIONS THAT HAVE OVERALL TRENDED FAVORABLY TOWARD THE  
WPC COMPOSITE SOLUTION, BOLSTERING FORECAST CONFIDENCE.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
00 UTC FORECAST GUIDANCE IS BETTER CLUSTERED WITH AN IMPORTANT  
SHORTWAVE TROUGH EXITING THE MID-ATLANTIC SATURDAY THAT OFFERS  
POTENTIAL FOR COASTAL STORM DEVELOPMENT. THE 00 UTC MODELS BETTER  
AGREE WITH DEVELOPMENT OF AN ORGANIZED LOW OFF THE MID-ATLANTIC  
AND NEW ENGLAND. THE WPC WINTER WEATHER OUTLOOK HOLDS A LINGERING  
CHANCE FOR COASTAL SNOWS INTO DAY 4/SATURDAY WITH THE EXITING LOW  
GIVEN THE THREAT OF A FEW MORE ROBUST ENSEMBLE MEMBERS.  
 
UPSTREAM, MODELS GENERALLY AGREE TO CARVE OUT A SOUTHWEST  
U.S/NORTHERN MEXICO CLOSED LOW BY SATURDAY THAT OFFERS TERRAIN  
ENHANCED SNOW POTENTIAL FROM THE MOGOLLON RIM TO THE SOUTHERN  
ROCKIES/HIGH PLAINS. THE SYSTEM REMAINS SLATED TO BE EJECTED  
EASTWARD ACROSS THE U.S. SOUTHERN TIER EARLY NEXT WEEK. LEAD  
MOISTURE RETURN FROM THE GULF OF MEXICO WILL OVERRUN A  
TRAILING/WAVY FRONT TO FUEL A DECENT SWATH OF PRECIPITATION WITHIN  
A COOLED AIRMASS FROM TEXAS EASTWARD ACROSS THE GULF COAST.  
 
SCHICHTEL  
 
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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