299
FXUS02 KWBC 211955
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
355 PM 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 COUPLE OF SHORTWAVES ARE FORECAST TO MOVE ACROSS THE NORTHERN
TIER STATES WITHIN BROAD TROUGHING THAT DIPS INTO THE EASTERN TWO-
THIRDS OF THE COUNTRY THROUGH THE MEDIUM-RANGE PERIOD. AN UPPER
LEVEL RIDGE WILL MAINTAIN THE HEAT ACROSS THE DESERT SOUTHWEST
INTO PORTIONS OF THE INTERMOUNTAIN WEST BEFORE A MORE PRONOUNCED
TROUGH DIPS INTO THE PACIFIC NORTHWEST BY NEXT WEEKEND. 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, THE UPPER TROUGH
WILL HERALD THE ARRIVAL OF COLDER WEATHER INTO THE NORTHWESTERN
QUADRANT OF THE COUNTRY WITH A DOUBLE-BARREL LOW-PRESSURE SYSTEM
DEVELOPING ON THE LEE OF THE ROCKIES.
..GUIDANCE/PREDICTABILITY ASSESSMENT
WITHIN THE BROAD TROUGHING ACROSS THE EASTERN TWO-THIRDS OF THE
COUNTRY, MODEL GUIDANCE IS SHOWING A GRADUAL SLOWING TREND AND WITH
LESS AMPLITUDE FOR THE TWO SHORTWAVE TROUGHS MOVING ACROSS THE
NORTHERN TIER STATES, WHICH IS UNCHARACTERISTIC FOR THE MEDIUM-
RANGE PERIOD. OVERALL AGREEMENT IS GOOD FOR THE UPPER TROUGH/CLOSED
LOW REACHING THE PACIFIC NORTHWEST BY THE END OF THE WEEK WITH A
SLIGHTLY EARLIER ARRIVAL TIME. ACROSS THE CENTRAL U.S., THE ECMWF
HAS BEEN FAVORING A MORE SOUTHERN QPF AXIS FROM D5/FRIDAY ONWARD
ACROSS THE CENTRAL U.S. VERSUS THE GFS CLUSTER, WHICH SHOWS A MORE
NORTHERN AND PROGRESSIVE QPF AXIS ACROSS THE MIDWEST. THERE HAS
BEEN A GENERAL CONSENSUS TO TREND TOWARD THE GFS CLUSTER AS THE
WARM FRONT AHEAD OF THE DOUBLE-BARREL AND ELONGATED LOW-PRESSURE
SYSTEM DEVELOPS OVER THE HIGH PLAINS.
OVER THE PACIFIC NORTHWEST, MODELS ARE SIGNALING COLDER POST-
FRONTAL ENVIRONMENT NEXT WEEKEND, WITH RAIN/SNOW MIX OR WET SNOW
ACROSS THE HIGHER-ELEVATIONS OF CENTRAL IDAHO AND NORTHWESTERN
WYOMING. IN ADDITION, THERE IS GOOD AGREEMENT ON THE PLACEMENT OF
THE MODERATE TO PERHAPS LOCALLY HEAVY RAIN ACROSS THE NORTHERN
PLAINS PRECEDING THE ELONGATED LOW-PRESSURE SYSTEM OVER THE HIGH
PLAINS.
..WEATHER/HAZARDS HIGHLIGHTS
THE WEATHER PATTERN WILL REMAIN QUITE UNSETTLED FROM THE CENTRAL
PLAINS ACROSS ARKANSAS AND SOUTHWESTERN MISSOURI THROUGH THE
MIDDLE OF THE WEEK WITH MULTIPLE ROUNDS OF THUNDERSTORMS AND
LOCALLY HEAVY RAINFALL. 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. A
MARGINAL EXCESSIVE RAINFALL IS DEPICTED FOR THIS AREA IN THE
OUTLOOK MAP. 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. PORTIONS
OF SOUTH-CENTRAL OREGON AS WELL AS THE HIGHER-ELEVATIONS OF
CENTRAL IDAHO AND NORTHWESTERN WYOMING COULD COOL BELOW FREEZING BY
NEXT WEEKEND, WITH RAIN/SNOW OR WET SNOW POSSIBLE OVER THE HIGHER
ELEVATIONS. MODERATE TO PERHAPS LOCALLY HEAVY RAIN AND EMBEDDED
THUNDERSTORMS ARE FORECAST ACROSS THE NORTHERN PLAINS PRECEDING THE
ELONGATED LOW-PRESSURE SYSTEM OVER THE HIGH PLAINS. MEANWHILE, HOT
AND HUMID CONDITIONS WILL CONTINUE UNABATED ACROSS THE DEEP SOUTH
AND GULF COAST REGION.
KONG/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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