695
FXUS02 KWBC 310654
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 AM EDT FRI JUL 31 2026
VALID 12Z MON AUG 03 2026 - 12Z FRI AUG 07 2026
...HEAT WAVE LIKELY TO CONTINUE ACROSS THE SOUTHWEST AND
INTERMOUNTAIN WEST INTO NEXT WEEK...
..PATTERN OVERVIEW
THE UPPER RIDGE DOMINATING THE WEATHER PATTERN ACROSS THE WESTERN
HALF OF THE COUNTRY WILL WEAKEN SLIGHTLY EARLY NEXT WEEK AS A
STRONG COLD FRONT IS FORECAST TO BRING MUCH COOLER AIR THROUGH THE
NORTHWEST AND INTO THE NORTHERN PLAINS THE FIRST HALF OF THE WEEK.
MEANWHILE, A SLOWLY DISSIPATING FRONT MERGING WITH A WAVE LIFTING
FROM THE MIDWEST TO THE NORTHEAST WILL TRIGGER SCATTERED SHOWERS
AND THUNDERSTORMS WHICH WILL GRADUALLY EDGE TOWARD THE EAST COAST
THROUGH MUCH OF THE WEEK. EXCESSIVE HEAT ACROSS THE SOUTHWESTERN
QUADRANT OF THE COUNTRY SHOULD BEGIN TO SPREAD NORTHEAST TOWARD THE
FOUR CORNERS, CENTRAL ROCKIES AND EVENTUALLY PARTS OF THE CENTRAL
HIGH PLAINS HEADING TOWARD MIDWEEK AS THE UPPER RIDGE RE-
INTENSIFIES.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST MODELS AND ENSEMBLES CONTINUE TO SHOW FAIRLY GOOD
OVERALL SYNOPTIC SCALE AGREEMENT ACROSS THE CONUS THROUGH THE
MEDIUM RANGE FORECAST PERIOD. EVEN AS EARLY AS MONDAY, THERE IS
SOME UNCERTAINTY STILL ON THE DEEP TROUGH OVER THE EAST AND HOW
QUICKLY THE FRONT/TROUGH CLEARS THE REGION, WITH SOME GUIDANCE
SUGGESTING SOME WEAK ENERGY MAY LINGER. BEHIND THIS, ANOTHER
SHORTWAVE WILL MOVE THROUGH THE NORTHERN U.S. AND INTO THE GREAT
LAKES REGION NEXT WEEK, WITH SOME REINFORCING SHORTWAVES AND
UNCERTAINTY IN THE TIMING AND DEPTH OF THOSE SYSTEMS. THE STRENGTH
OF THE RIDGE OUT WEST SHOWS SOME DIFFERENCES, WITH THE CONSENSUS
SUGGESTING POSSIBLY SOME WEAK ENERGY WORKING TO SUPPRESS SLIGHTLY.
THE GFS SEEMS TO BE THE OUTLIER BRINGING A DEEP UPPER LOW INTO THE
NORTHWEST LATE NEXT WEEK WHICH DOES NOT HAVE SUPPORT FROM OTHER
GUIDANCE AT THIS POINT.
THE WPC FRONTS/PRESSURES WERE BASED ON A BLEND OF THE
DETERMINISTIC GUIDANCE FOR DAYS 3-4, INCREASING GRADUALLY THE
WEIGHTING OF ENSEMBLE MEAN GUIDANCE FOR DAYS 5-7 TO 60 PERCENT OF
THE TOTAL BLEND. THIS HELPS SMOOTH OUT THE BIGGER DIFFERENCES WHILE
MAINTAINING GOOD AGREEMENT WITH THE PREVIOUS WPC FORECAST AS WELL.
..WEATHER/HAZARDS HIGHLIGHTS
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE MORE BROADLY
ACROSS THE EAST COAST STATES INTO MONDAY AS DEEPER MOISTURE IS
ADVECTED NORTHWARD AHEAD OF THE UPPER TROUGH ACROSS THE MID- SOUTH.
THE RAINFALL COULD BE POTENTIALLY MORE CONCENTRATED ACROSS LOWER
GREAT LAKES, UPSTATE NEW YORK INTO WESTERN PA WHERE INTERACTION
WITH A COLD FRONT COULD ENHANCE COVERAGE OF SHOWERS AND STORMS.
RAINFALL LIKELY LINGERS ACROSS THE EAST COAST STATES THROUGH MUCH
OF THE WEEK AHEAD OF THE NEXT TROUGH INTO THE GREAT LAKES MID TO
LATE NEXT WEEK.
HEAT ACROSS MUCH OF THE INTERMOUNTAIN WEST FOR THE SHORT RANGE
SHOULD BE SUPPRESSED SOUTHWARD BY MONDAY AS A COLD FRONT SINKS
ACROSS THE NORTHERN TIER. HOWEVER, WIDESPREAD MAJOR TO EXTREME
HEATRISK WILL CONTINUE THROUGH AT LEAST MID WEEK FOR MUCH OF THE
SOUTHWEST, AND INTO PARTS OF THE INTERMOUNTAIN WEST. SEE KEY
MESSAGES ISSUED BY WPC FOR THIS EVENT FOR ADDITIONAL INFORMATION
REGARDING THIS LONG LASTING AND DANGEROUS HEAT WAVE. HEAT THREATS
MAY INCREASE LATER IN THE PERIOD FOR PARTS OF THE CENTRAL ROCKIES
AND HIGH PLAINS AND EVENTUALLY INTO THE MID SOUTH AS THE UPPER
RIDGE EXPANDS EASTWARD.
ELSEWHERE ACROSS THE CONTINENTAL U.S., MOST OF THE MONSOONAL
RAINFALL SHOULD BE CONFINED TO EASTERN ARIZONA AND INTO CENTRAL NEW
MEXICO, WITH SCATTERED CONVECTION REACHING INTO PORTIONS OF UTAH
AND COLORADO. A CORRIDOR OF SHOWERS AND STORMS IS LIKELY AHEAD OF
THE FRONT THAT CROSSES THE DAKOTAS AND INTO MINNESOTA EARLY IN THE
WEEK, AND THIS MAY ALSO BE ACCOMPANIED WITH SOME SEVERE WEATHER.
THE PACIFIC NORTHWEST WILL LIKELY HAVE SOME SLIGHTLY BELOW AVERAGE
TEMPERATURES THIS WEEKEND BEFORE A GRADUAL WARM-UP ENSUES NEXT
WEEK, AND GENERALLY CLOSE TO AVERAGE FOR THE EASTERN U.S.
SANTORELLI
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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