362
FXUS02 KWBC 111939
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
339 PM EDT SAT JUL 11 2026
VALID 12Z TUE JUL 14 2026 - 12Z SAT JUL 18 2026
...DANGEROUS HEAT CONTINUES ACROSS THE NORTH-CENTRAL U.S. THROUGH
NEXT WEEK WHILE RAMPING BACK UP OVER THE EAST COAST...
..OVERVIEW
AN ELONGATED AND ANOMALOUSLY STRONG UPPER-LEVEL RIDGE WILL BE IN
PLACE FROM THE INTERMOUNTAIN WEST THROUGH THE MIDWEST NEXT WEEK,
LEADING TO A SIGNIFICANT AND DANGEROUS HEAT WAVE CONTINUING ACROSS
THOSE REGIONS. RAIN AND THUNDERSTORMS ARE LIKELY ON THE SOUTHERN
PERIPHERY OF THE RIDGE, WITH ELEVATED CHANCES OF HEAVY RAIN AND
FLASH FLOODING IN WESTERN/CENTRAL TEXAS IN PARTICULAR.
ADDITIONALLY, MONSOONAL MOISTURE IS FORECAST TO INCREASE AND
PRODUCE SHOWERS AND STORMS ACROSS THE SOUTHWEST, FOUR CORNERS
STATES, AND NORTHWARD INTO THE NORTHERN ROCKIES/HIGH PLAINS. SOME
ENERGIES ON THE NORTHERN SIDE OF THE RIDGE COULD ALSO LEAD TO
ROUNDS OF RAIN AND THUNDERSTORMS IN THE NORTHERN TIER, INCLUDING A
NORTHERN NEW ENGLAND SEVERE THREAT TUESDAY AND LATE WEEK OVER THE
MID-ATLANTIC WITHIN A RENEWED PRE-FRONTAL EAST COAST HEAT THREAT.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODEL GUIDANCE CONTINUES TO SHOW GOOD AGREEMENT IN TERMS OF THE
594+ DM UPPER HIGH CENTERED NEAR THE NORTH-CENTRAL U.S. AND
MEANDERING NEXT WEEK, LEADING TO HIGH CONFIDENCE IN MULTIPLE DAYS
OF HAZARDOUS HEAT. MODELS INDICATE THE RIDGE SHOULD STRETCH INTO
PARTS OF THE NORTHEAST TUESDAY BEFORE GETTING SUPPRESSED BY INTO
THE MID-ATLANTIC BY AN UPPER TROUGH MOVING IN BY THE LATTER HALF
OF THE WEEK. THE RIDGE AXIS THERE MAY JOIN WITH THE SUBTROPICAL
ATLANTIC HIGH THAT SHIFTS WEST THROUGH LATER NEXT WEEK. MEANWHILE
FARTHER WEST, THE RIDGE SHOULD GET RENEWED ACROSS THE
NORTHERN/CENTRAL ROCKIES AND PLAINS.
SMALLER-SCALE ENERGIES TO THE SOUTH OF THE RIDGE ARE RELATIVELY
MORE UNCERTAIN, BUT THERE IS AN INCREASING SIGNAL FOR LOWER HEIGHTS
WITH ENERGY ALOFT ACROSS THE SOUTHERN HIGH PLAINS MIDWEEK,
YIELDING INCREASING QPF. MEANWHILE A NORTHEASTERN PACIFIC UPPER LOW
HAS SHOWN NOTABLE VARIATIONS IN THE GUIDANCE RECENTLY. THE
EVOLUTION OF THE LOW AS IT TRACKS INLAND AND EASTWARD ON THE
NORTHERN PERIPHERY OF THE RIDGE NEXT WEEK REMAINS A BIT UNCERTAIN.
OVERALL, A BROAD MODEL/ENSEMBLE MEAN/MACHINE LEARNING GUIDANCE
COMPOSITE BLEND SEEMED TO PRODUCE A REASONABLE FORECAST BASIS FOR
MUCH OF THE DOMAIN DURING THIS MEDIUM-RANGE FORECAST PERIOD THAT
TENDS TO MITIGATE SMALLER SCALE DIFFERENCES AS CONSISTENT WITH
INDIVIDUAL PREDICTABILITY. THIS PLAN MAINTAINS REASONABLE WPC
PRODUCT CONTINUITY.
..WEATHER/HAZARDS HIGHLIGHTS
IT GENERALLY REMAINS THE CASE THAT A STRONG AND EXPANSIVE RIDGE
SPRAWLING FROM THE WESTERN U.S. TO THE CENTRAL U.S. WILL LEAD TO AN
EXTENDED PERIOD OF DANGEROUS HEAT FOR PARTS OF THE INTERMOUNTAIN
WEST, NORTHERN PLAINS, AND UPPER MIDWEST NEXT WEEK. SEVERAL DAYS OF
WELL ABOVE NORMAL AND POTENTIALLY RECORD-BREAKING MAXIMUM AND
MINIMUM TEMPERATURES WILL LEAD TO MAJOR TO EXTREME HEATRISK. WPC
CONTINUES TO UPDATE HEAT KEY MESSAGES FOR THIS EVENT, WHICH CAN BE
FOUND ON OUR HOMEPAGE. COVERAGE OF THE DANGEROUS HEAT COULD
GRADUALLY BECOME MORE LIMITED INTO LATE WEEK. FARTHER EAST, PERIODS
OF WARMER THAN AVERAGE TEMPERATURES ARE LIKELY FOR THE NORTHEAST
PARTICULARLY ON TUESDAY, SHIFTING INTO THE MID-ATLANTIC MIDWEEK AND
BEYOND WHILE THE NORTHEAST COOLS BEHIND A COLD FRONT. THE UPPER
RIDGE POTENTIALLY COMBINING WITH SUBTROPICAL RIDGING DOWN TO
FLORIDA WILL MAINTAIN WARM TEMPERATURES AND AN ELEVATED HEATRISK.
MEANWHILE, MUCH OF THE SOUTHERN TIER COULD SEE NEAR TO SLIGHTLY
BELOW AVERAGE TEMPERATURES AS A FRONT STALLS NEAR THE GULF COAST
AND ACTS AS A FOCUS FOR SHOWERS AND THUNDERSTORMS THROUGH AT LEAST
MIDWEEK. THE VERY MOIST AND UNSTABLE ENVIRONMENT COULD LEAD TO
FLASH FLOODING CONCERNS, AND BROAD MARGINAL RISKS OF FLASH FLOODING
ARE IN PLACE FOR DAYS 4-5 (TUESDAY-WEDNESDAY). EMBEDDED SLIGHT
RISKS ARE IN PLACE ACROSS PORTIONS OF TEXAS, WHERE PACIFIC AND GULF
MOISTURE SHOULD COMBINE IN THE VICINITY OF A SHORTWAVE ALOFT.
MEANWHILE, PREFRONTAL INSTABILITY AND MOISTURE WILL BE IN PLACE
ACROSS THE NORTHEAST ON TUESDAY, AND THE STORM PREDICTION CENTER
HAS DELINEATED A SEVERE THREAT IN NORTHERN NEW ENGLAND. SPC ALSO
SHOWS A SEVERE AREA OVER THE MID-ATLANTIC TO MONITOR FOR FRIDAY.
INCREASING SOUTHERLY FLOW AROUND THE WESTERN PERIPHERY OF THE
CENTRAL U.S. RIDGE WILL DRAW SIGNIFICANT MONSOONAL MOISTURE INTO
THE SOUTHWEST AND INTERMOUNTAIN WEST TO ROCKIES NEXT WEEK. THIS
MOISTURE WILL LEAD TO SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WITH THE POTENTIAL TO PRODUCE HEAVY RAINFALL AND
LOCALIZED FLASH FLOODING. SENSITIVE PLACES SUCH AS BURN SCARS,
STEEP TERRAIN, ETC., WOULD BE THE MOST VULNERABLE TO ANY FLOODING
CONCERNS THAT MAY DEVELOP. BROAD MARGINAL RISKS OF EXCESSIVE
RAINFALL REMAIN IN PLACE FOR TUESDAY/WEDNESDAY FROM THE SOUTHWEST
NORTH TO MONTANA. RAINFALL POTENTIAL SHOULD CONTINUE FOR THAT
REGION THROUGH LATE WEEK, WHILE POSSIBLE NORTHERN TIER SHORTWAVES
YIELD INCREASING RAIN CHANCES FOR THE GREAT LAKES AND VICINITY.
TATE/SCHICHTEL
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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