704  
FXUS02 KWBC 051817  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
216 PM EDT SUN JUN 05 2022  
 
VALID 12Z WED JUN 08 2022 - 12Z SUN JUN 12 2022  
   
..OVERVIEW AND SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
A SERIES OF 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 THE HEAVIEST RAIN WILL  
REMAIN EXTREMELY DIFFICULT TO PINPOINT GIVEN THE CONVECTIVE NATURE  
OF THIS ACTIVITY, THOUGH LOCAL FLOODING CONCERNS MAY BE POSSIBLE  
WITHIN CONVECTIVE CLUSTERS AND WHERE CELLS REPEAT/TRAIN. THE BEST  
SIGNAL AT THIS POINT FOR THIS WOULD BE ACROSS THE TENNESSEE VALLEY  
ON WEDNESDAY, AND FROM THE CENTRAL PLAINS TO MID-MISSISSIPPI  
VALLEY ON THURSDAY (WHERE SPC HIGHLIGHTS A CHANCE FOR SEVERE  
WEATHER AS WELL). THE PATTERN LOOKS TO AMPLIFY BY THE LATTER HALF  
OF THE PERIOD, BRINGING A COLD FRONT AND POSSIBLY MORE WIDESPREAD  
RAINS TO PARTS OF THE EAST NEXT WEEKEND. MEANWHILE, MUCH OF THE  
WEST SHOULD STAY DRY UNTIL LATE WEEK INTO NEXT WEEKEND WHEN A  
PACIFIC SYSTEM APPROACHING THE COAST BRINGS A PERIOD OF ENHANCED  
MOISTURE AND RAINFALL MAINLY TO THE PACIFIC NORTHWEST. AN UPPER  
RIDGE CENTERED OVER THE SOUTH WILL CONTINUE NEAR RECORD DAYTIME  
TEMPERATURES MORE THAN 10 DEGREES ABOVE NORMAL ACROSS TEXAS  
THROUGH MOST OF THE PERIOD. AND LEAD UPPER RIDGE AMPLIFICATION  
AHEAD OF THE SYSTEM INTO THE WEST 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, AT LEAST TO  
START. THERE REMAIN SOME QUESTIONS IN THE SMALLER SCALE DETAILS  
WHICH LIKELY WILL TAKE UNTIL THE SHORT RANGE TO RESOLVE BUT A  
GENERAL MODEL BLEND OF THE GFS/ECMWF/UKMET/CANADIAN SEEMS TO  
PROVIDE A GOOD STARTING POINT WEDNESDAY INTO FRIDAY. MODELS AND  
ENSEMBLES CONTINUE TO INCREASINGLY SHOW A SIGNAL FOR A MORE  
AMPLIFIED FLOW PATTERN BY NEXT WEEKEND, THOUGH WITH INCREASING  
FORECAST SPREAD. THE 00Z CMC WAS STRONGER/MORE AMPLIFIED WITH THE  
TROUGHING INTO THE EAST NEXT WEEKEND, WHILE THE GFS AND ECMWF  
OFFERED SOMETHING A LITTLE WEAKER AND FASTER. THE ENSEMBLE MEANS  
WERE ALSO WEAKER, AS EXPECTED, BUT A LITTLE SLOWER THAN THE GFS  
AND ECMWF WITH THE TROUGH AXIS. TIMING ISSUES OUT WEST BETWEEN THE  
GFS/ECMWF AND THE CMC ALSO INCREASED LATE PERIOD UNCERTAINTY. WPC  
PRODUCTS INTO DAYS 6-7 (NEXT WEEKEND) INCREASINGLY WEIGHED TOWARDS  
THE GEFS/ECMWF ENSEMBLE MEANS, WITH LESSER INPUT FROM THE BEST  
MATCHED GFS/ECMWF FOR BETTER SYSTEM DEFINITION. THIS ALSO HELPED  
TO MAINTAIN GOOD WPC PRODUCT CONTINUITY.  
 
SANTORELLI/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  
 

 
 

 
 
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