124  
FXUS02 KWBC 151841  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
240 PM EDT FRI JUL 15 2022  
 
VALID 12Z MON JUL 18 2022 - 12Z FRI JUL 22 2022  
 
...DANGEROUS HEAT TO PERSIST OVER MUCH OF THE WESTERN AND CENTRAL  
U.S. NEXT WEEK...  
   
..OVERVIEW
 
 
HOT TEMPERATURES WILL PREVAIL ACROSS A LARGE AREA OF THE  
CENTRAL/WESTERN U.S. UNDERNEATH A STRONG UPPER RIDGE CENTERED OVER  
THE FOUR CORNERS REGION. NEAR OR RECORD HIGHS WILL BE POSSIBLE AT  
TIMES. MEANWHILE, THE FLOW AROUND THE RIDGE WILL BRING PERIODIC  
EPISODES OF SHOWERS AND THUNDERSTORMS AND HELP TO REINFORCE THE  
LONG TERM MEAN TROUGH OVER THE NORTHEASTERN U.S. THROUGH THE  
PERIOD. FOR THE SOUTHWEST U.S. INTO THE ROCKIES, SOME MONSOONAL  
MOISTURE UNDER THE RIDGE WILL PROVIDE DAILY CHANCES OF SHOWERS AND  
STORMS, SOME OF WHICH COULD LEAD TO FLASH FLOODING. FINALLY, THE  
WEST COAST WILL TEND TO SEE WEAK TROUGHING.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
IN A FAIRLY TYPICAL SUMMER-TIME PATTERN, THE LARGE SCALE PATTERN  
SHOWED FAIRLY GOOD AGREEMENT AND CONSISTENCY BETWEEN THE VARIOUS  
GLOBAL MODELS AND WPC CONTINUITY. THE CENTER OF THE UPPER RIDGE IS  
FORECAST TO REMAIN CENTERED OVER THE FOUR CORNERS THROUGH LATE  
NEXT WEEK WHILE TROUGHING PREVAILS OVER THE GREAT LAKES AND  
NORTHEAST. THE LATEST GUIDANCE SHOWS FAIRLY GOOD AGREEMENT IN THE  
SURFACE EVOLUTION OF A STRONG WAVE OF LOW PRESSURE TRACKING ACROSS  
THE NORTHERN PLAINS EARLY NEXT WEEK THROUGH THE GREAT LAKES BY  
MID-WEEK, WITH ITS TRAILING COLD FRONT ADVANCING ACROSS THE  
CENTRAL U.S., REACHING THE MID-MS, TENNESSEE VALLEY AND EAST COAST  
BY THE END OF NEXT WEEK. THE TIMING AND PROGRESSION OF THIS  
FEATURE STILL HAS MODEL AGREEMENT ISSUES, WITH THE GFS BEING A  
FAST PROGRESSIVE OUTLIER COMPARED TO THE OTHER GUIDANCE. THE  
UPDATED FORECAST BASED ON GUIDANCE THROUGH THE 12Z/18Z CYCLES  
EMPHASIZED THE OPERATIONAL RUNS FOR ABOUT THE FIRST HALF OF THE  
PERIOD, WITH GFS INPUT TILTED TOWARD THE 12Z RUN FOR ITS BETTER  
CLUSTERING WITH THE NORTHERN TIER UPPER LOW EARLY IN THE WEEK.  
GENERAL AGREEMENT ON THE MEAN PATTERN BUT INCREASING DETAIL  
UNCERTAINTIES LED TO A TRANSITION TOWARD NEARLY HALF TOTAL INPUT  
FROM THE ENSEMBLE MEANS BY LATE IN THE PERIOD. GFS INPUT REVERTED  
BACK EXCLUSIVELY TO THE 18Z RUN FOR ITS INCOMING NORTHEASTERN  
PACIFIC TROUGH WHILE ENSEMBLE MEAN INPUT WAS SPLIT AMONG THE  
ECENS/CMCENS/GEFS TO DOWNPLAY THE LESS DESIRABLE GEFS EVOLUTION  
OVER EASTERN CANADA AND VICINITY.  
 
   
..WEATHER/HAZARDS HIGHLIGHTS
 
 
EXPECT THE GREATEST TEMPERATURE ANOMALIES TO BE OVER THE  
CENTRAL/NORTHERN PLAINS EARLY NEXT WEEK WHERE HIGHS 15 TO 20  
DEGREES ABOVE NORMAL ARE LIKELY. TRIPLE DIGIT HIGHS ARE EXPECTED  
FROM TEXAS NORTHWARD THROUGH PORTIONS OF THE DAKOTAS AND A FEW  
DAILY TEMPERATURE RECORDS ARE POSSIBLE. MONSOONAL MOISTURE AND  
ASSOCIATED DIURNALLY FAVORED SHOWERS/STORMS WITH LOCALLY HEAVY  
RAINFALL MAY KEEP PARTS OF THE FOUR CORNERS/GREAT BASIN REGION  
CLOSER TO NORMAL FOR HIGHS WHILE OTHER PARTS OF THE WEST SHOULD BE  
SOMEWHAT WARMER THAN NORMAL. EXCEPTIONS WILL BE OVER THE FAR  
NORTHERN ROCKIES UNDER THE INITIAL UPPER LOW/TROUGH AS WELL AS  
ALONG THE IMMEDIATE WEST COAST WITH READINGS CLOSER TO NORMAL.  
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH A STRONGER SYSTEM  
FORECAST TO TRACK ACROSS THE NORTHERN TIER, GREAT LAKES, AND  
NORTHEAST MID WEEK WITH WARMER THAN NORMAL TEMPERATURES LIKELY  
AHEAD OF THAT FRONTAL PASSAGE. PERSISTENT MOISTURE WILL ALLOW FOR  
MULTIPLE EPISODES OF SHOWERS/THUNDERSTORMS OVER THE  
SOUTHEAST/FLORIDA AND CENTRAL GULF COAST REGION. TEMPERATURES  
SHOULD BE NEAR NORMAL OVER THOSE AREAS.  
 
RAUSCH/TAYLOR  
 
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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