631  
FXUS02 KWBC 140701  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
259 AM EDT TUE JUN 14 2022  
 
VALID 12Z FRI JUN 17 2022 - 12Z TUE JUN 21 2022  
 
...HEAT WAVE EXPECTED ACROSS THE NORTHERN/CENTRAL PLAINS FRIDAY  
THROUGH THE WEEKEND, SLOWLY MODERATING AND SHIFTING SLIGHTLY  
EASTWARD EARLY NEXT WEEK...  
 
   
..OVERVIEW AND GUIDANCE/PREDICTABILITY EVALUATION
 
 
GUIDANCE AGREES WELL IN DEPICTING AN AMPLIFIED UPPER PATTERN FROM  
LATE WEEK THROUGH THE WEEKEND, WITH A CENTRAL U.S. RIDGE  
SEPARATING ONE TROUGH/EMBEDDED LOW BEGINNING TO MOVE INTO THE WEST  
AND ANOTHER TROUGH DIGGING OVER THE EAST COAST/WESTERN ATLANTIC  
(WITH A POSSIBLE LOW OVER MAINE AND/OR THE CANADIAN MARITIMES).  
BY THE FIRST PART OF NEXT WEEK THE CORE OF THE WESTERN TROUGH  
ENERGY SHOULD EJECT NORTHEASTWARD TO YIELD A WEAKER/BROADER MEAN  
TROUGH OVER THE WEST, WHILE THE UPPER RIDGE REACHING THE  
EAST-CENTRAL U.S. AND DOWNSTREAM TROUGH SHOULD REMAIN RATHER  
AMPLIFIED. THIS PATTERN SHOULD BRING MULTIPLE DAYS OF  
PRECIPITATION TO THE NORTHWEST/NORTHERN ROCKIES AS WELL AS  
POTENTIAL FOR ENHANCED RAINFALL OVER PARTS OF THE FOUR CORNERS  
STATES, ALONG WITH A PERIOD OF COOL TEMPERATURES AS THE UPPER  
TROUGH/LEADING FRONT PUSH EASTWARD. MEANWHILE SOME LOCATIONS IN  
THE NORTHERN PLAINS COULD SEE HIGHS UP TO 20-25F ABOVE NORMAL LATE  
WEEK THROUGH THE WEEKEND WITH A FEW RECORD HIGHS POSSIBLE,  
FOLLOWED BY A GRADUAL COOLING TREND. THE UPPER TROUGH/EMBEDDED  
LOW NEAR THE EAST COAST WILL SUPPORT A COOL WEEKEND AND PERHAPS  
SOME SHOWERS OVER THE NORTHEAST.  
 
WITH GFS RUNS HAVING SETTLED INTO THE PRIMARY CLUSTER FOR THE EAST  
COAST/WESTERN ATLANTIC UPPER TROUGH OVER THE PAST 24 HOURS,  
SOLUTIONS ARE NOW SIMILAR IN PRINCIPLE. ONE ITEM OF INTEREST  
DETAIL-WISE IS THAT BY SUNDAY THE 12Z ECMWF ADJUSTED SOMEWHAT  
WEAKER WITH THE CORE OF THE UPPER TROUGH AND LESS DEFINED WITH THE  
POSSIBLE UPPER LOW VERSUS A NUMBER OF PREVIOUS RUNS WHILE OTHER  
SOLUTIONS ARE DEEPER THAN THE 12Z ECMWF. A GENERAL BLEND WOULD  
PROVIDE A STABLE FORECAST. DEEPER TREND IN THE NEW 00Z ECMWF  
SUPPORTS THIS IDEA. FOR THE DEEP TROUGH REACHING THE WEST COAST  
BY AROUND EARLY SATURDAY, THE MODELS HAVE TENDED TO BE FAIRLY  
SIMILAR UP TO ABOUT FOUR DAYS OUT IN TIME BEFORE STRAYING WITH  
DETAILS OF WHERE THE EMBEDDED UPPER LOW MAY TRACK AND HOW QUICKLY  
IT WILL EJECT FROM THE WEST. GFS/ECMWF RUNS HAVE BEEN ERRATIC  
OVER RECENT DAYS WHILE THE CMC HAS GENERALLY BEEN ON THE SLOW SIDE  
BUT TRENDS FASTER IN THE NEW 00Z RUN. THE MULTI-DAY CONSISTENCY  
OF THE ENSEMBLE MEANS FOR THE OVERALL TROUGH WOULD SUPPORT  
CONTINUED INCLUSION OF THEIR SOLUTIONS AS PART OF THE OVERALL  
BLEND BY THE LATTER HALF OF THE PERIOD, WITH INDIVIDUAL MODEL  
DIFFERENCES CANCELING OUT. THUS GUIDANCE COMPARISONS LED TO  
STARTING THE UPDATED FORECAST WITH THE 12Z/18Z OPERATIONAL MODELS  
FRIDAY INTO SUNDAY AND THEN TRENDING TOWARD HALF MODELS AND HALF  
18Z GEFS/12Z ECMWF MEANS BY DAY 7 TUESDAY.  
   
..SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
THE COLD FRONT REACHING THE EAST COAST LATE THIS WEEK WILL PRODUCE  
SOME SHOWERS AND THUNDERSTORMS WITH SOME RAINFALL ALSO POSSIBLE  
FARTHER BACK TO THE WEST. THE DEEP UPPER TROUGH SETTING UP NEAR  
THE EAST COAST AND POSSIBLE UPPER LOW OVER MAINE AND/OR THE  
CANADIAN MARITIMES MAY BRING MULTIPLE DAYS OF COOL AND AT TIMES  
SHOWERY WEATHER TO THE NORTHEAST. THE SOUTHEAST AND GULF COAST  
REGIONS WILL SEE DIURNALLY FAVORED SHOWERS AND THUNDERSTORMS LATE  
THIS WEEK AND THEN OVER THE FLORIDA PENINSULA FROM THE WEEKEND  
INTO NEXT WEEK AS THE FRONT PUSHING INTO THE SOUTHEAST STALLS.  
THE UPPER TROUGH REACHING THE NORTHWEST COAST BY FRIDAY NIGHT OR  
EARLY SATURDAY SHOULD INITIALLY BRING LIGHT TO LOCALLY MODERATE  
RAINFALL TO PARTS OF THE NORTHWEST. PRECIPITATION EXTENDING INTO  
THE NORTHERN ROCKIES BY THE WEEKEND AND EARLY NEXT WEEK (SNOW  
LIKELY LIMITED TO HIGHEST ELEVATIONS) MAY BECOME HEAVIER DEPENDING  
ON EXACTLY HOW ENERGY EJECTS FROM THE MEAN TROUGH AND THE DEGREE  
OF INTERACTION WITH LEADING MOISTURE FLOW FROM THE SOUTH. THE  
UNUSUALLY EARLY MONSOON TYPE PATTERN WILL BRING MUCH ABOVE NORMAL  
MOISTURE FOR THE TIME OF YEAR NORTHWARD THROUGH THE FOUR CORNERS  
STATES AND VICINITY FROM LATE THIS WEEK THROUGH THE WEEKEND,  
SUPPORTING AN INCREASE IN COVERAGE AND INTENSITY OF RAINFALL  
ACROSS THE REGION. RAIN/THUNDERSTORMS SHOULD CONTINUE INTO EARLY  
NEXT WEEK AS THE MOISTURE INTERACTS WITH THE FRONT SLOWLY  
ADVANCING THROUGH THE WEST.  
 
THE MOST ANOMALOUS TEMPERATURES DURING THE PERIOD WILL BE WITH  
WITH A FAIRLY BRIEF HEAT WAVE ACROSS THE NORTHERN HALF OF THE  
PLAINS, WITH MOST AREAS SEEING A COUPLE DAYS WITH HIGHS REACHING  
20-25F ABOVE NORMAL. THIS HEAT MAY PIVOT AROUND THE CENTRAL  
PORTIONS OF THE PLAINS WHERE PLUS 10-20F ANOMALIES MAY BE MORE  
PERSISTENT. SOME DAILY RECORDS FOR HIGHS AND WARM LOWS WILL BE  
POSSIBLE. A FRONT MOVING INTO THE PLAINS SHOULD START A MODEST  
COOLING TREND/EASTWARD SHIFT OF THE HEAT EARLY NEXT WEEK. THE  
EAST WILL SEE A PRONOUNCED COOLING TREND HEADING INTO THE WEEKEND,  
WITH HIGHS UP TO 5-10F BELOW NORMAL OVER THE NORTHEAST. BY EARLY  
NEXT WEEK THE PLAINS/MISSISSIPPI VALLEY UPPER RIDGE MAY REACH FAR  
ENOUGH EAST TO BRING A RETURN OF HOT WEATHER TO THE TENNESSEE  
VALLEY AND SOUTHEAST, WITH DECENT COVERAGE OF PLUS 10-15F HIGH  
TEMPERATURE ANOMALIES NEXT TUESDAY. COOL AIR PUSHING INTO THE  
WEST LATE WEEK THROUGH THE WEEKEND WILL SUPPORT HIGHS UP TO 10-15F  
BELOW NORMAL BEFORE READINGS TREND CLOSER TO NORMAL EARLY NEXT  
WEEK.  
 
RAUSCH  
 
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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