047
FXUS02 KWBC 161833
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
233 PM EDT THU JUL 16 2026
VALID 12Z SUN JUL 19 2026 - 12Z THU JUL 23 2026
...DANGEROUS HEAT WILL GRADUALLY SUBSIDE IN THE NORTH-CENTRAL U.S.
EARLY NEXT WEEK...
..OVERVIEW
AN UPPER RIDGE OVER THE WESTERN AND CENTRAL U.S. INTO SUNDAY WILL
CONTINUE TO CAUSE DANGEROUS HEAT ACROSS THE NORTHERN/CENTRAL
PLAINS. THE NORTHEAST SIDE OF THE RIDGE WILL GET GRADUALLY
SUPPRESSED BY SHORTWAVE ENERGY ENTERING THE MIDWEST/GREAT LAKES
INTO A NORTHEASTERN U.S. UPPER TROUGH, WHICH WILL BRING RELIEF FROM
THE HEAT TO NORTHERN AREAS AS THE TROUGH PUSHES COLD FRONTS
THROUGH THE REGION. THE SHORTWAVES AND FRONTS IN THE BROADER TROUGH
SHOULD ALSO YIELD ROUNDS OF RAIN AND THUNDERSTORMS IN THE GREAT
LAKES TO EAST COAST NEXT WEEK. ADDITIONALLY, AMPLE MONSOONAL
MOISTURE WILL CONTINUE TO STREAM INTO THE SOUTHWEST AND
INTERMOUNTAIN WEST, PRODUCING ROUNDS OF SHOWERS AND THUNDERSTORMS.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODEL GUIDANCE IS GENERALLY STILL AGREEABLE ON THE LARGE SCALE
PATTERN, BUT SOME UNCERTAINTY LINGERS WITH THE DETAILS ESPECIALLY
LATE PERIOD. THIS MOSTLY SURROUNDS A SHORTWAVE ROUNDING THE TOP OF
THE CENTRAL U.S. RIDGE INTO THE GREAT LAKES EARLY NEXT WEEK, WHICH
WILL ACT TO DEEPEN THE EASTERN TROUGH AND PUSH THE UPPER RIDGE AXIS
WESTWARD A BIT INTO THE INTERMOUNTAIN WEST. THE ECMWF IS NOTABLY
STRONGER/SHARPER WITH THIS SHORTWAVE BY MID NEXT WEEK OVER THE
NORTHEAST, WHILE THE BETTER CONSENSUS IS MORE SHALLOW WITH THE
SURFACE LOW DISPLACED MORE NORTHWARD. UNCERTAINTY ALSO IS PRESENT
ALONG THE NORTHWEST COAST AS TROUGHING TRIES TO MOVE INTO THE
REGION LATE PERIOD.
PLENTY OF UNCERTAINTY IN THE NORTHEAST GULF WITH POTENTIAL
DEVELOPMENT OF A TROPICAL LOW. RECENT GUIDANCE CONTINUES TO BE
RELATIVELY WEAK WITH THE LOW, AND IF IT DEVELOPS TRUE TROPICAL
CHARACTERISTICS, IT WOULD BE MORE TOWARDS THE END OF THE SHORT
RANGE PERIOD. REGARDLESS, THERE IS BETTER CONFIDENCE FOR SOME
REFLECTION OF THE LOW OR AN ELONGATED TROUGH OVER THE SOUTHEAST TO
ENHANCE RAIN ACROSS PARTS OF FLORIDA AND THE SOUTHEAST. NHC
CONTINUES TO TRACK THIS WITH LOW PROBABILITIES OF FORMATION.
THE WPC FORECAST WAS BASED ON A MULTI-MODEL BLEND EARLY IN THE
PERIOD, WITH INCREASING PROPORTIONS OF THE ENSEMBLE MEANS (AND LESS
OF THE ECMWF) BY DAY 7.
..WEATHER/HAZARDS HIGHLIGHTS
ANOTHER HOT DAY IS IN STORE SUNDAY FOR THE NORTHERN/CENTRAL
PLAINS, AS TEMPERATURES NEAR/EXCEED 100F, YIELDING MAJOR TO
ISOLATED EXTREME HEATRISK. WPC CONTINUES TO UPDATE HEAT KEY
MESSAGES FOR THIS EVENT, WHICH CAN BE FOUND ON OUR HOMEPAGE. THE
RIDGE INFLUENCE FARTHER SOUTH WILL ALSO LEAD TO GENERALLY MAJOR
HEATRISK STRETCHING INTO THE CENTRAL PLAINS AND MIDDLE/LOWER
MISSISSIPPI VALLEY TO SOUTHEAST. THE HOT CONDITIONS SHOULD SLOWLY
EASE IN THE NORTHERN STATES INTO THE WORKWEEK, BUT BE MAINTAINED IN
THE SOUTH. TEMPERATURES A FEW DEGREES ABOVE ALREADY WARM AVERAGES
COMBINED WITH HIGH HUMIDITY COULD LEAD TO INCREASED HEATRISK IN THE
SOUTH-CENTRAL U.S. AND GULF COAST STATES.
MEANWHILE, THE SOUTHWESTERN TO SOUTH-CENTRAL U.S. COULD SEE
SLIGHTLY BELOW AVERAGE TEMPERATURES AS AMPLE MOISTURE LEADS TO
CLOUDS AND RAIN/THUNDERSTORMS. CONTINUED SOUTHERLY FLOW UNDER THE
BROAD UPPER RIDGE WILL DRAW SIGNIFICANT MONSOONAL MOISTURE INTO THE
SOUTHWEST AND INTERMOUNTAIN WEST TO ROCKIES. 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 ARE IN PLACE FROM THE
SOUTHWEST ACROSS MUCH OF THE INTERMOUNTAIN WEST FOR DAY 4-5
(SUNDAY-MONDAY). COVERAGE OF SHOWERS AND THUNDERSTORMS SHOULD
GRADUALLY INCREASE EASTWARD OVER THE ROCKIES AND HIGH PLAINS EARLY
TO MIDWEEK.
ELSEWHERE, SOUTHERN STREAM ENERGY IS FORECAST TO MEANDER IN THE
NORTHEASTERN GULF IN A MOIST AND UNSTABLE ENVIRONMENT EARLY NEXT
WEEK. TROUGHING AND TROPICAL MOISTURE IN PLACE (EVEN IF THERE IS NO
TRUE TROPICAL LOW) COULD LEAD TO HEAVY RAIN, AND MARGINAL RISKS
ARE IN PLACE FOR PORTIONS OF NORTHERN/CENTRAL FLORIDA FOR ISOLATED
FLASH FLOODING ON SUNDAY AND MONDAY. MEANWHILE THE TAIL END OF A
FRONTAL BOUNDARY COULD HANG UP IN EASTERN NORTH CAROLINA AND
VIRGINIA AND PRODUCE LOCALLY HEAVY RAIN ON SUNDAY. THE NEXT ROUND
OF RAIN AND THUNDERSTORMS IS FORECAST TO COME THROUGH THE MIDWEST
AND GREAT LAKES EARLY NEXT WEEK UNDERNEATH A SHORTWAVE ALOFT. AS
THE SHORTWAVE AND FRONT MOVE SOUTHEAST, RAIN CHANCES SHOULD
OVERSPREAD MUCH OF THE EASTERN U.S. FOR TUESDAY-WEDNESDAY.
SANTORELLI/TATE
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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