464  
FXUS02 KWBC 050640  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
238 AM EDT SUN JUN 05 2022  
 
VALID 12Z WED JUN 08 2022 - 12Z SUN JUN 12 2022  
   
..OVERVIEW AND SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
SHORTWAVES WITHIN NEAR ZONAL FLOW WILL ACT TO LOCALLY ENHANCE A  
BROADLY ACTIVE CONVECTIVE WEATHER PATTERN FROM THE ROCKIES/PLAINS  
TO THE EAST THIS WEEK AS HEAVY RAINFALL AND STRONG THUNDERSTORMS  
ARE FUELED BY MOISTURE AND INSTABILITY POOLING NEAR A WAVY FRONTAL  
BOUNDARY. EXACT LOCATIONS OF HEAVIEST RAIN WILL REMAIN EXTREMELY  
DIFFICULT TO PINPOINT GIVEN THE CONVECTIVE NATURE OF THIS  
ACTIVITY. CONVECTIVE CLUSTERS AND REPEAT/TRAINING CELLS COULD  
PRODUCE EARLY PERIOD LOCAL RUNOFF ISSUES WITH PERHAPS THE  
STRONGEST SIGNAL FROM THE CENTRAL PLAINS TO THE MID-SOUTH AND  
AGAIN LATER WEEK AS UPPER TROUGH AMPLIFICATION/DIFFLUENCE MAY  
REFOCUS AND BETTER ORGANIZE CONVECTIVE RAINFALL POTENTIAL IN THIS  
SUSCEPTABLE AREA AND VICINITY. ACTIVITY WILL TRY TO WORK INTO THE  
SUMMER WARMTH ACROSS A U.S SOUTHERN TIER UNDER THE INLFUENCE OF AN  
UPPER RIDGE. NEAR RECORD DAYTIME TEMPERATURES MORE THAN 10F ABOVE  
NORMAL ARE POSSIBLE IN THIS AIRMASS OVER PARTS OF TEXAS.  
 
MEANWHILE, MUCH OF THE WEST SHOULD STAY DRY UNTIL LATE WEEK INTO  
THE NEXT WEEKEND WHEN A PACIFIC SYSTEM APPROACHING THE COAST  
BRINGS A PERIOD OF ENHANCED MOISTURE AND RAINFALL MAINLY TO THE  
PACIFIC NORTHWEST. LEAD UPPER RIDGE AMPLIFICATION ALSO FAVORS  
BUILDING EXCESSIVE HEAT ACROSS THE INTERIOR VALLEYS OF CALIFORNIA  
AND THE DESERT SOUTHWEST LATE WEEK INTO NEXT WEEKEND TO INCLUDE  
SOME LOCAL RECORD VALUES.  
   
..MODEL GUIDANCE EVALUATION/PREFERENCES
 
 
GUIDANCE CONTINUES TO SHOW ABOVE AVERAGE AGREEMENT AND  
PREDICTABILITY WITH THE MID-LARGER SCALE FLOW EVOLUTION THROUGH  
MID-LATE WEEK IN A PATTERN WITH RELATIVELY ZONAL FLOW. THERE  
REMAIN SOME QUESTIONS IN THE SMALLER SCALE DETAILS WHICH LIKELY  
WILL TAKE UNTIL THE SHORT RANGE TO RESOLVE. A GENERAL MODEL BLEND  
OF THE GFS/ECMWF/UKMET/CANADIAN AND NATIONAL BLEND OF MODELS SEEMS  
TO PROVIDE A GOOD STARTING POINT WEDNESDAY INTO FRIDAY. MODELS AND  
ENSEMBLES INCREASINGLY SHOW A SIGNAL FOR A MORE AMPLIFIED FLOW  
PATTERN BY NEXT WEEKEND, THOUGH WITH INCREASING FORECAST SPREAD.  
WPC PRODUCTS INTO DAYS 6-7 (NEXT WEEKEND) INCREASINGLY WEIGHED  
TOWARDS THE DECENTLY CLUSTERED GEFS/ECMWF ENSEMBLE MEANS, WITH  
LESSER INPUT FROM THE BEST MATCHED GFS/ECMWF FOR BETTER SYSTEM  
DEFINITION. WPC PRODUCT CONTINUITY IS WELL MAINTAINED.  
 
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, 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  
 

 
OVERTOP U.S. SOUTHERN TIER UPPER RIDGING SUMMER HEAT ACROSS THE  
SOUTH MAY NEAR RECORD LEVELS OVER PARTS OF TEXAS.  
 

 
 
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