400
FXUS02 KWBC 101900
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 PM EDT WED JUN 10 2026
VALID 12Z SAT JUN 13 2026 - 12Z WED JUN 17 2026
...HEAT BUILDING ACROSS THE WEST THIS WEEKEND INTO EARLY NEXT
WEEK...
...HEAVY RAINFALL THREAT IN SOUTHERN/CENTRAL PARTS OF THE PLAINS
AND MISSISSIPPI VALLEY EXPANDING INTO THE SOUTHEAST...
..OVERVIEW
A BROAD UPPER TROUGH WITH EMBEDDED SHORTWAVES WILL BE PRESENT
ACROSS THE NORTHERN TIER OF THE U.S. AS THE MEDIUM RANGE PERIOD
BEGINS SATURDAY, WHILE SUBTROPICAL RIDGING SETS UP OVER THE
SOUTHERN TIER AND BRINGS HOT TEMPERATURES/HEAT INDICES THERE. A
FRONTAL BOUNDARY AHEAD OF THE TROUGH IS FORECAST TO MEANDER ACROSS
THE SOUTH-CENTRAL U.S. AND FOCUS MOISTURE FOR RAIN AND
THUNDERSTORMS. HEAVY RAINFALL IS POSSIBLE WITH MULTIPLE ROUNDS OF
STORMS EXPECTED TO SET UP IN THE SOUTHERN/CENTRAL PLAINS AND
LOWER/MID-MISSISSIPPI VALLEY OVER THE WEEKEND. A SHORTWAVE DIGGING
ON THE WESTERN SIDE OF THE UPPER TROUGH WILL SERVE TO DEEPEN IT AS
THE WORKWEEK PROGRESSES, WHICH SHOULD PUSH THE FRONT EAST AND BRING
HEAVY RAIN TO THE SOUTHEAST. COOLER AIR FILTERS INTO THE CENTRAL
AND EASTERN U.S. IN THE WAKE OF THE FRONT, WITH HIGHS TRENDING
BELOW SEASONAL NORMS. UPSTREAM, UPPER RIDGING IS FORECAST TO BUILD
ACROSS THE WEST COAST, LEADING TO HOT TEMPERATURES THAT WILL BE
WELL ABOVE AVERAGE IN THE PACIFIC NORTHWEST EARLY NEXT WEEK, WITH
SOME UNCERTAINTY IN HOW LONG THE HEAT WILL LAST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
COMPUTER MODELS CONTINUE TO HAVE A REASONABLY GOOD HANDLE ON THE
LARGE SCALE PATTERN THROUGH MOST OF THE MEDIUM RANGE PERIOD, WITH
RIDGING FLANKING A BROAD CENTRAL U.S. TROUGH. DESPITE SOME
LINGERING DIFFERENCES WITH SMALLER SCALE DETAILS LEADING TO MINOR
IMPACTS ON THE TIMING AND PLACEMENT OF FRONTS, PRESSURES, AND QPF,
THE SPREAD BETWEEN GUIDANCE IS GRADUALLY SHRINKING AND OUTLIER
SOLUTIONS ARE CORRECTING TO CONSENSUS. THIS IS ESPECIALLY EVIDENT
WITH THE EVOLUTION OF A POTENT SHORTWAVE ACROSS THE NORTHERN
ROCKIES THAT IS EXPECTED TO DIG SOUTHEASTWARD AND DEEPEN THE
CENTRAL U.S. TROUGH THIS WEEKEND INTO EARLY NEXT WEEK. CONTINUING
THE TREND FROM 00Z, MOST OF THE NEW 12Z GUIDANCE HAS BECOME BETTER
ALIGNED WITH A FASTER, MORE EASTWARD TROUGH POSITION AND
PROGRESSION. THIS INCLUDES THE GFS WHICH IS STILL ON THE WESTERN
SIDE OF GUIDANCE BUT MUCH FARTHER EAST THAN BEFORE.
THE LATEST WPC FORECAST WAS BASED ON THE AVAILABLE 00Z/06Z
GUIDANCE SUITE FEATURING A MULTI-MODEL BLEND EARLY IN THE PERIOD,
WITH INCREASING WEIGHTING PLACED ON ENSEMBLE MEANS (AND LESS SO ON
THE 06Z GFS) FOR THE LATTER HALF OF THE PERIOD. ENSEMBLE MEANS
COMPRISED NEARLY HALF OF THE BLEND FOR FRONTS/PRESSURES BY DAY 7.
..WEATHER/HAZARDS HIGHLIGHTS
LOW PRESSURE/FRONTAL SYSTEMS CONVERGING IN THE CENTRAL U.S. WILL
PROVIDE A FOCUS FOR THUNDERSTORMS THIS WEEKEND. AMPLE MOISTURE AND
INSTABILITY WILL MEAN SEVERE AND FLASH FLOODING THREATS ARE BOTH
POSSIBLE FOR PARTS OF THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI
VALLEY ON SATURDAY, AND SHIFTED SOMEWHAT SOUTH INTO THE SOUTHERN
PLAINS/LOWER MISSISSIPPI VALLEY ON SUNDAY AS THE FRONTS MOVE SOUTH.
SLIGHT RISKS ARE PRESENT IN BOTH THE DAY 4/SATURDAY AND 5/SUNDAY
EROS--SEE THE NEW DAY 4-5 ERO DISCUSSION FOR MORE. AS THE FRONT
CONTINUES TO PRESS SLOWLY SOUTHEAST, AREAS OF HEAVY RAIN ARE
POSSIBLE IN THE TENNESSEE VALLEY TO SOUTHEAST WESTWARD INTO THE
LOWER MISSISSIPPI VALLEY TO TEXAS ON MONDAY AND TUESDAY. RAIN AND
THUNDERSTORMS ARE ALSO POSSIBLE THROUGH THE GREAT LAKES/OHIO VALLEY
TO APPALACHIANS AND EASTERN SEABOARD AT TIMES ALONG THE NORTHERN
PARTS OF THE FRONTS, THOUGH WITH UNCERTAINTY IN THE DETAILS.
ELSEWHERE, THE NORTHERN ROCKIES/HIGH PLAINS SHOULD SEE A ROUND OF
PRECIPITATION THIS WEEKEND AS THE SHORTWAVE ALOFT MOVES THROUGH,
WITH SOME SNOW POSSIBLE IN HIGHER ELEVATIONS. WEST OF THE ROCKIES
SHOULD REMAIN DRY UNDER THE UPPER RIDGING.
HOT AND HUMID CONDITIONS WILL BE PRESENT ACROSS THE SOUTHERN
PLAINS TO SOUTHEAST OVER THE WEEKEND UNDER THE SUBTROPICAL UPPER
RIDGE. THE EASTERN SEABOARD CAN EXPECT GENERALLY ABOVE NORMAL
TEMPERATURES, BUT MODERATED FROM THE HEAT IN THE SHORT RANGE
PERIOD. COOLER THAN AVERAGE TEMPERATURES ARE LIKELY UNDERNEATH THE
UPPER TROUGH IN THE NORTH-CENTRAL U.S., SPREADING INTO THE SOUTH
AND EAST AS THE WEEK PROGRESSES WHILE MODERATING. MEANWHILE, THE
WEST WILL BE WARMING UP. THE DESERT SOUTHWEST CAN EXPECT
TEMPERATURES WELL INTO THE 100S AND PERHAPS OVER 110 OVER THE
WEEKEND, WITH WARMER THAN AVERAGE TEMPERATURES EXTENDING INTO THE
CENTRAL GREAT BASIN. ABOVE AVERAGE TEMPERATURES WILL CONTINUE TO
SPREAD NORTHWARD INTO THE PACIFIC NORTHWEST OVER THE WEEKEND AND
EARLY NEXT WEEK. DAILY RECORD HIGHS COULD BE BROKEN AS TEMPERATURES
REACH THE 90S IN THE WILLAMETTE VALLEY AND 80S FARTHER NORTH
TOWARD SEATTLE. WIDESPREAD MODERATE TO SCATTERED MAJOR HEATRISK IS
FORECAST FOR MUCH OF THE WEST.
TATE/MILLER
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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