315
FXUS02 KWBC 220758
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
358 AM EDT MON JUN 22 2026
VALID 12Z THU JUN 25 2026 - 12Z MON JUN 29 2026
***ADDITIONAL HEAVY RAIN FOR THE CENTRAL PLAINS AND VERY HOT
CONDITIONS FOR THE DESERT SOUTHWEST THROUGH FRIDAY***
..GENERAL OVERVIEW
A RELATIVELY ZONAL UPPER LEVEL FLOW PATTERN IS EXPECTED TO BE IN
PLACE FOR THE BEGINNING OF THE FORECAST PERIOD THURSDAY, AND THE
UPPER RIDGE OVER THE SOUTHWEST STATES WEAKENS AFTER FRIDAY. THIS
WILL BE DUE TO AN AMPLIFYING TROUGH OVER THE NORTHWESTERN QUADRANT
OF THE COUNTRY OVER THE WEEKEND, BRINGING A WELCOMED COOL DOWN
AFTER A HOT WEEK. THIS STRONG TROUGH WILL SUPPORT AN ORGANIZED LOW
PRESSURE SYSTEM THAT WILL EMERGE FROM THE ROCKIES TO THE
CENTRAL/NORTHERN PLAINS WITH A RELATIVELY POTENT COLD FRONT
CROSSING THE PACIFIC NORTHWEST AND INTERMOUNTAIN WEST. THIS WILL
LIKELY RESULT IN A DOWNSTREAM UPPER RIDGE DEVELOPING OVER THE
EAST-CENTRAL U.S. TOWARDS EARLY NEXT WEEK WITH A RETURN TO HOTTER
TEMPERATURES FOR MUCH OF THAT REGION.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE 00Z MODEL GUIDANCE SUITE FEATURED GOOD OVERALL SYNOPTIC SCALE
AGREEMENT OVERALL FOR THE END OF THE WEEK, WITH GOOD OVERALL
CONSENSUS ON THE UPPER TROUGH/CLOSED LOW DROPPING SOUTH ACROSS THE
PACIFIC NORTHWEST. 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 40% 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 THURSDAY AND FRIDAY, AND TEMPERATURES LOWERED FOR COASTAL
AREAS OF THE MID-ATLANTIC, NORTHEAST, AND THE GREAT LAKES.
..WEATHER/HAZARDS HIGHLIGHTS
MULTIPLE MESOSCALE CONVECTIVE SYSTEMS ARE LIKELY TO AFFECT MUCH OF
THE CENTRAL PLAINS AND EXTENDING EASTWARD TO INCLUDE THE OHIO
VALLEY THROUGH THE END OF THE WEEK AND INTO THE WEEKEND, WITH SOME
AREAS GETTING AN ADDITIONAL 2-4 INCHES OF RAIN OVER ALREADY
SATURATED GROUNDS FROM RECENT HEAVY RAINFALL. A LINGERING FRONTAL
BOUNDARY WITH SHORTWAVE ENERGY ALOFT AND STRONG MOISTURE
CONVERGENCE WILL PROVIDE ENOUGH INSTABILITY AND LIFT TO SUSTAIN
THESE THUNDERSTORM COMPLEXES, AND SOME OF THESE STORMS COULD
PRODUCE FLASH FLOODING. SOME STRONG TO SEVERE THUNDERSTORMS ARE
ALSO A DISTINCT POSSIBILITY, PARTICULARLY ACROSS THE WESTERN HIGH
PLAINS ON THURSDAY.
ELSEWHERE ACROSS THE NATION, RAINFALL INCREASES FOR WASHINGTON AND
OREGON TO CLOSE OUT THE WORK WEEK WITH THE STORM SYSTEM MOVING
THROUGH THE REGION, AND A LARGER AREA OF HEAVIER RAINFALL DEVELOPS
ACROSS THE DAKOTAS AS THE MAIN SURFACE LOW EJECTS EASTWARD OVER THE
NORTHERN PLAINS BY THE WEEKEND. SCATTERED SHOWERS AND THUNDERSTORMS
ARE ALSO EXPECTED FOR THE EAST COAST THROUGH SATURDAY WITH
INCREASING LOW LEVEL MOISTURE IN PLACE.
THE WIDESPREAD ABOVE AVERAGE HEAT LEVELS ACROSS THE WESTERN THIRD
OF THE NATION ARE LIKELY TO CONTINUE GOING INTO THURSDAY, WITH 110S
LIKELY FOR THE LOWER ELEVATIONS OF THE DESERT SOUTHWEST, AND 90S
EXTENDING AS FAR NORTH AS SOUTHERN IDAHO. A STRONG COLD FRONT
BRINGS RELIEF FROM THE HEAT STARTING FRIDAY AND BECOMING EVEN MORE
NOTICEABLE GOING INTO THE WEEKEND AS HIGHS RETURN TO BELOW AVERAGE
BY LATE JUNE STANDARDS, WHEREAS OVERNIGHT LOWS SHOULD BE LESS
ANOMALOUS. THE OPPOSITE HOLDS TRUE FOR THE SOUTHERN HIGH PLAINS
WHERE TEMPERATURES ARE LIKELY TO INCREASE BY THE WEEKEND WITH HIGHS
WELL INTO THE 100S FOR WESTERN TEXAS, AND BUILDING HEAT AND
HUMIDITY FOR MUCH OF THE CENTRAL AND EASTERN U.S. GOING INTO SUNDAY
AND MONDAY AS THE UPPER RIDGE DOMINATES THE WEATHER PATTERN.
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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