486
FXUS02 KWBC 210756
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
356 AM EDT SUN JUN 21 2026
VALID 12Z WED JUN 24 2026 - 12Z SUN JUN 28 2026
***ADDITIONAL HEAVY RAIN FOR THE CENTRAL PLAINS AND VERY HOT
CONDITIONS FOR THE DESERT SOUTHWEST THROUGH FRIDAY***
..GENERAL OVERVIEW
A QUASI-ZONAL UPPER LEVEL FLOW PATTERN WILL BE IN PLACE ACROSS THE
COUNTRY FOR THE BEGINNING OF THE PERIOD WEDNESDAY. AN UPPER LEVEL
RIDGE WILL BUILD ACROSS THE DESERT SOUTHWEST INTO PORTIONS OF THE
INTERMOUNTAIN WEST, WITH INCREASING HEAT THROUGH THE END OF THE
WEEK. A LINGERING FRONTAL BOUNDARY DRAPED ACROSS THE MID-SOUTH TO
THE CENTRAL PLAINS, COUPLED WITH SOME SHORTWAVE ENERGY ALOFT, WILL
FUEL THE DEVELOPMENT OF MULTIPLE THUNDERSTORM COMPLEXES THAT WILL
BRING EPISODES OF HEAVY RAINFALL. BY NEXT WEEKEND, AN ORGANIZED
LOW PRESSURE SYSTEM AND COLD FRONT CROSS THE NORTHWESTERN QUADRANT
OF THE COUNTRY AND WILL HERALD THE ARRIVAL OF COOLER WEATHER FOR
MUCH OF THE WESTERN U.S.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE 00Z MODEL GUIDANCE SUITE FEATURED GOOD OVERALL SYNOPTIC SCALE
AGREEMENT OVERALL FOR MUCH OF THE WEEK, WITH GOOD OVERALL CONSENSUS
ON THE UPPER TROUGH/CLOSED LOW DROPPING SOUTH ACROSS THE PACIFIC
NORTHWEST TOWARDS THE END OF THE WEEK. THE GFS HAS TRENDED CLOSER
TO THE CONSENSUS ACROSS THE NORTHERN ROCKIES AND INTERMOUNTAIN WEST
COMPARED TO EARLIER RUNS THAT INDICATED A LEAD TROUGH CUTTING
ACROSS THE RIDGE AXIS. MORE MODEL DIFFERENCES ARE APPARENT BY NEXT
WEEKEND AS THE TROUGH REACHES THE NORTHERN ROCKIES AND THE
DOWNSTREAM RIDGE THAT BUILDS AHEAD OF IT ACROSS THE MIDWEST STATES.
THE ENSEMBLE MEANS WERE INCREASED TO ABOUT HALF BY NEXT SUNDAY. THE
NBM WAS A REASONABLE STARTING POINT FOR MOST AREAS OF THE COUNTRY,
ALTHOUGH QPF WAS RAISED ACROSS PORTIONS OF THE INTERIOR SOUTHWEST
U.S. FOR WEDNESDAY THROUGH FRIDAY, AND TEMPERATURES LOWERED FOR
COASTAL AREAS OF THE MID-ATLANTIC AND NORTHEAST.
..WEATHER/HAZARDS HIGHLIGHTS
THE WEATHER PATTERN WILL REMAIN QUITE UNSETTLED FROM THE CENTRAL
PLAINS TO THE ARKLATEX REGION THROUGH THE MIDDLE OF THE WEEK WITH
MULTIPLE ROUNDS OF THUNDERSTORMS WITH HEAVY RAINFALL EXPECTED. THIS
IS IN ASSOCIATION WITH A FRONTAL BOUNDARY THAT WILL BE IN PLACE
ACROSS THIS REGION, WITH ANOMALOUS MOISTURE SURGING NORTH AND
FUELING THE CONVECTION THAT DEVELOPS. GOING INTO THE END OF THE
WEEK, THE HEAVIEST RAINFALL IS EXPECTED FROM EASTERN KANSAS TO
CENTRAL ILLINOIS WHERE ADDITIONAL THUNDERSTORM COMPLEXES ARE
EXPECTED TO DEVELOP AND LEAD TO PERIODS OF HEAVY RAINFALL, AND THIS
WILL LIKELY BE THE CASE FOR THE OHIO VALLEY GOING INTO SATURDAY.
TEMPERATURES ARE EXPECTED TO BE VERY PLEASANT BY LATE JUNE
STANDARDS ACROSS A LARGE EXPANSE OF THE NORTH-CENTRAL STATES
THROUGH MUCH OF NEXT WEEK, WITH HIGHS GENERALLY IN THE 70S AND
COMFORTABLE HUMIDITY LEVELS GIVEN THE OVERALL DIP IN THE JET STREAM
AND BROAD UPPER TROUGH IN PLACE. MOST OF THE MID- ATLANTIC AND
NORTHEAST SHOULD BE CLOSE TO SEASONAL AVERAGES WITH HIGHS MAINLY IN
THE UPPER 70S TO UPPER 80S. WITH THE UPPER RIDGE OVER THE WEST
THROUGH FRIDAY, HEAT IS EXPECTED TO BUILD FROM THE DESERT SOUTHWEST
TO THE PACIFIC NORTHWEST, WITH HIGHS GENERALLY RUNNING 5 TO 10
DEGREES ABOVE NORMAL IN MANY CASES. A PATTERN CHANGE IS EXPECTED TO
ARRIVE NEXT SATURDAY AS A COLD FRONT DROPS SOUTH ACROSS THE
PACIFIC NORTHWEST AND BRINGS AN END TO THE HEAT WAVE THERE. HOT AND
HUMID CONDITIONS WILL CONTINUE UNABATED ACROSS THE DEEP SOUTH AND
GULF COAST REGION.
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 FORECAST, EXCESSIVE RAINFALL OUTLOOK,
WINTER WEATHER OUTLOOK PROBABILITIES, HEAT INDICES AND KEY MESSAGES
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
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW
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