580  
FXUS02 KWBC 240656  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
255 AM EDT TUE MAY 24 2022  
 
VALID 12Z FRI MAY 27 2022 - 12Z TUE MAY 31 2022  
   
..WEATHER PATTERN OVERVIEW
 
 
A LARGE SCALE UPPER TROUGH WITH A POSSIBLE EMBEDDED CLOSED LOW  
WILL BE CROSSING THE EASTERN U.S. THROUGH FRIDAY AND INTO  
SATURDAY, AND THIS WILL SUSTAIN A SURFACE COLD FRONT THAT SHOULD  
EXIT THE EAST COAST BY THE WEEKEND. MEANWHILE, ANOTHER TROUGH  
ENTERS THE NORTHWESTERN U.S. BY THE END OF THE WEEK WITH A BRIEF  
UPPER RIDGE AHEAD OF IT ACROSS THE ROCKIES AND THE HIGH PLAINS.  
MODELS SUGGEST THIS TROUGH WILL DEEPEN AS IT CROSSES THE WEST THIS  
WEEKEND WITH SURFACE CYCLOGENESIS ACROSS THE NORTHERN PLAINS THIS  
WEEKEND. IN RESPONSE TO THE DIGGING UPPER TROUGH, AN UPPER RIDGE  
SHOULD BUILD ACROSS THE EASTERN U.S. ALONG WITH WARMER  
TEMPERATURES. THIS GENERAL AMPLIFIED PATTERN IS FORECAST TO  
PERSIST INTO EARLY NEXT WEEK.  
   
..MODEL GUIDANCE AND PREFERENCES
 
 
THE 00Z MODEL GUIDANCE IS TRENDING MORE TOWARDS A SLOWER AND  
POTENTIALLY CLOSED UPPER LOW SOLUTION ACROSS THE OHIO VALLEY FOR  
THE FRIDAY-SATURDAY TIME PERIOD, WITH THE PAST FEW RUNS OF THE GFS  
CONSISTENTLY ON THE SLOWER SIDE OF THE MODEL CONSENSUS. THE CMC  
IS NOW ON THE FASTER SIDE AND HAS LESS OF A CLOSED LOW SIGNAL  
COMPARED TO THE ECMWF/GFS/UKMET. THEREFORE, THE WPC FORECAST  
THROUGH SATURDAY FOCUSED MORE TOWARDS THE ECMWF/CMC/UKMET AS A  
STARTING POINT. OUT WEST, THE GUIDANCE SHOWS GOOD TIMING  
AGREEMENT ON THE INITIAL SHORTWAVE INTO THE WEST LATE THIS WEEK,  
BUT DIFFER WITH THE EVOLUTION INTO THE WEEKEND, WITH THE GFS  
STRONGER AND THE CMC/ECMWF A LITTLE SLOWER. THE WPC FORECAST  
TRENDED TOWARDS THE ENSEMBLE MEANS FOR THE SECOND HALF OF THE  
PERIOD TO ACCOUNT FOR THIS UNCERTAINTY AND GENERALLY SHOWS GOOD  
CONTINUITY WITH THE PREVIOUS WPC FORECAST AS WELL.  
   
..SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
THE MAJORITY OF THE HEAVY RAINFALL SHOULD BE OVER BY FRIDAY,  
ALTHOUGH A CORRIDOR OF SHOWERS AND STORMS IS EXPECTED ACROSS THE  
EAST COAST STATES AHEAD OF A WEAKENING COLD FRONT. THERE IS THE  
POTENTIAL FOR SOME REPEATED ROUNDS OF CONVECTION WITH HEAVY RAIN  
ACROSS PORTIONS OF THE CAROLINAS BASED ON SOME OF THE LATEST MODEL  
GUIDANCE, BUT RIGHT NOW THE POTENTIAL FOR ANY FLOODING APPEARS  
MARGINAL. PATCHY AREAS OF HEAVY RAINFALL ARE ALSO POSSIBLE ACROSS  
PORTIONS OF THE NORTHEAST, ALTHOUGH THE SYSTEM SHOULD BE MORE  
PROGRESSIVE HERE. BY THIS WEEKEND, SHOWERS AND STORMS INCREASE IN  
COVERAGE ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST IN RESPONSE  
TO A DEVELOPING LOW PRESSURE SYSTEM OVER THE NORTH-CENTRAL U.S.  
SOME LATE SEASON HIGH ELEVATION SNOW IS ALSO POSSIBLE ACROSS THE  
NORTHERN ROCKIES FOR THE SUNDAY AND MONDAY TIME PERIOD.  
 
TEMPERATURES WILL WARM UP CONSIDERABLY ACROSS THE PLAINS BY THE  
END OF THE WEEK WITH HIGHS REACHING WELL INTO THE 90S FROM KANSAS  
TO THE GULF COAST, AND SOME LOW-MID 100S ACROSS WESTERN TEXAS.  
THE HEAT BUILDS EASTWARD TO INCLUDE THE OHIO VALLEY AND EVENTUALLY  
THE EAST COAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK,  
COMPLIMENTS OF THE BUILDING UPPER RIDGE AND SOUTHERLY FLOW AHEAD  
OF THE STORM SYSTEM OVER THE PLAINS. MUCH COOLER WEATHER ARRIVES  
FOR THE PACIFIC NORTHWEST BY FRIDAY, AND THE BELOW NORMAL  
TEMPERATURES ENCOMPASS THE NORTHERN ROCKIES AND NORTHERN PLAINS AS  
THE UPPER TROUGH MOVES IN BEHIND THE COLD FRONT.  
 
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, EXPERIMENTAL EXCESSIVE RAINFALL  
OUTLOOK, 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/#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  
 

 
 

 
 
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