587
FXUS02 KWBC 191816
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
216 PM EDT SUN JUL 19 2026
VALID 12Z WED JUL 22 2026 - 12Z SUN JUL 26 2026
...HAZARDOUS HEAT FOCUS OVER THE SOUTH THIS WEEK MAY EXPAND TO THE
NORTHERN PLAINS AND THE DESERT SOUTHWEST INTO NEXT WEEKEND...
..MONSOONAL RAINS FOR THE SOUTHWEST/INTERMOUNTAIN WEST/ROCKIES
...EAST/SOUTHEAST U.S. HEAVY RAINS TO WORK OVER THE GULF COAST WITH
POSSIBLE TROPICAL LOW DEVELOPMENT BEING MONITORED BY THE NHC...
..OVERVIEW
QUITE HOT AND MUGGY CONDITIONS WILL FOCUS OVER THE SOUTH FOR THE
COMING WEEK AS NORTHERN TIER SHORTWAVES AND MODERATING SURFACE
FRONTS BRING ROUNDS OF LOCALLY HEAVY RAINS AND A STRONG TO SEVERE
THUNDERSTORM FOCUS MID/LATER WEEK DOWN OVER THE MID-ATLANTIC. LEAD
ACTIVITY OVER THE SOUTH/SOUTHEAST WILL BE FUELED BY GULF/TROPICAL
MOISTURE AND THE NHC IS INVESTIGATING SYSTEM GENESIS. ELSEWHERE,
AMPLE MONSOONAL MOISTURE WILL CONTINUE TO STREAM FROM THE SOUTHWEST
AND INTERMOUNTAIN WEST/ROCKIES TO THE PLAINS TO FUEL ENHANCED
SHOWERS AND THUNDERSTORMS AS A CLOSED UPPER HIGH SHIFTS TO THE
SOUTHERN PLAINS BEFORE RE-EXPANDING HEAT UP THROUGH THE PLAINS AND
INTO THE SOUTHWEST AS MONSOONAL FLOW MAY EASE INTO NEXT WEEKEND.
MEANWHILE, CURRENT TROPICAL STORM ELIDA IS FORECAST BY NHC TO
DISSIPATE OVER THE NEXT FEW DAYS WHILE LIFTING NORTHWARD OFF THE
WEST COAST ~130W WITH LEAD MOISTURE FEEDING UP THE WEST COAST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
OVERALL GOOD AGREEMENT FOR THE LARGE-SCALE PATTERN ACROSS CONUS
WITH A RIDGE OVER THE WEST-CENTRAL U.S. AND TROUGHING ALONG THE
EAST. THERE IS SOME DIFFERENCES AMONG THE DETERMINISTIC MODELS
CONCERNING THE SMALLER-SCALE FEATURES, ESPECIALLY TOWARDS LATE
WEEK. ADDITIONALLY, THE GFS AND CMC DEPICTS A SHORTWAVE ENERGY
MOVING THROUGH THE NORTHERN ROCKIES EARLY IN THE PERIOD BUT THE
ECMWF KEPT THE RIDGING STRUCTURE THROUGH THE PERIOD. THESE
DIFFERENCE CAN AFFECT SENSIBLE WEATHER AND FRONTAL PLACEMENTS.
THEREFORE, MUCH OF THE FORECAST WEIGHED IN THE ENSEMBLE MEANS FROM
THE START OF THE PERIOD AND GRADUALLY OUTWEIGHED THE DETERMINISTIC
TOWARDS THE LATTER PORTION OF THE PERIOD. ACROSS THE GULF COAST,
MANY MODELS SHOW LARGE SPREAD AND DIFFERENCES CONCERNING THE
DEVELOPMENT OF THE TROPICAL SYSTEM. THE AIGFS AND EC-AIFS, HELPED
CAPTURE THE SHAPE AND TRACK OF THE SYSTEM THAT ALIGNED WITH NHC.
..WEATHER/HAZARDS HIGHLIGHTS
FLOW AROUND A MAIN UPPER RIDGE WILL CONTINUE TO DRAW SIGNIFICANT
MONSOONAL MOISTURE INTO THE SOUTHWEST AND INTERMOUNTAIN
WEST/ROCKIES THIS WEEK, BUT MAY EASE NEXT WEEKEND. MOISTURE WILL
FUEL SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WITH POTENTIAL
TO PRODUCE HEAVY RAINFALL AND LOCALIZED FLASH FLOODING. SENSITIVE
PLACES SUCH AS BURN SCARS, STEEP TERRAIN, ETC., WOULD BE THE MOST
VULNERABLE TO POSSIBLE FLOODING CONCERNS. BROAD MARGINAL RISKS OF
EXCESSIVE RAINFALL SPAN FROM THE SOUTHWEST AND INTERMOUNTAIN
WEST/ROCKIES TO THE CENTRAL PLAINS WEDNESDAY AND THURSDAY AND AN
EMBEDDED SLIGHT RISK AREA WAS INTRODUCED FOR THE NORTHERN
INTERMOUNTAIN WEST/ROCKIES FOR WEDNESDAY GIVEN ANOMALOUS MOISTURE.
UPPER RIDGE/CLOSED HIGH INFLUENCE SHIFT TO SOUTH-CENTRAL U.S. WILL
LEAD TO AT LEAST MAJOR HEATRISKS OVER MUCH OF THE SOUTH THIS WEEK
AS TEMPERATURES UPWARDS TO 5-10F ABOVE ALREADY HOT AVERAGES
COMBINE WITH HIGH HUMIDITY. EXPECT SPOTTY RECORD HIGHS AND MORE
WIDESPREAD RECORD OVERNIGHT LOWS TO LIMIT RELIEF. HEAT INDICES RISE
RISE UPWARDS TO 105-110+F IN SOME SPOTS, WITH FOCUS EXPANDING UP
THROUGH THE PLAINS AND INTO THE DESERT SOUTHWEST BY NEXT WEEKEND.
ELSEWHERE, HEAVY RAINS WITH STRONG TO SEVERE THUNDERSTORMS PER SPC
ARE FORECAST TO FOCUS INTO THE EAST COAST AND ESPECIALLY THE MID-
ATLANTIC/SOUTHEAST MID/LATER WEEK GIVEN SUPPORT ALOFT AND WAVY
FRONTAL PUSH. ELONGATED WPC EXCESSIVE RAINFALL MARGINAL RISK AREAS
OVER MUCH OF THE EAST COAST WEDNESDAY AND THURSDAY ALSO FEATURE
EMBEDDED SLIGHT RISK AREAS OVER THE COASTAL MID-ATLANTIC/CAROLINAS.
MEANWHILE TO THE SOUTH, A MOIST AND UNSTABLE ENVIRONMENT OVER THE
NORTHEASTERN GULF REMAINS MONITORED FOR A TROPICAL DEPRESSION BY
NHC. TROUGHING AND TROPICAL MOISTURE IN PLACE MAY LEAD TO HEAVY
RAIN. A MARGINAL RISK IS IN PLACE FROM THE COASTAL
SOUTHEAST/NORTHERN FLORIDA ALONG THE GULF COAST INTO TEXAS, WITH A
SLIGHT RISK ADDED ACROSS WEST-CENTRAL GULF COAST FOR FLASH
FLOODING THREATS POSSIBLE FOR WEDNESDAY AND THURSDAY.
OUDIT/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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