655
FXUS02 KWNH 060655
PREEPD
PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 AM EDT MON JUL 6 2026
VALID 12Z THU JUL 09 2026 - 12Z MON JUL 13 2026
...MAJOR HEATWAVE FOCUS OVER THE SOUTHEAST U.S. AND BUILDING OVER
THE SOUTHWEST/WEST-CENTRAL U.S. THROUGH THIS WEEK AND BEYOND...
..PATTERN OVERVIEW
AN UPPER-LEVEL RIDGE DEVELOPS OVER THE CENTRAL U.S. THROUGH THIS
WEEKEND, WHILE A SERIES OF SHORTWAVES MOVE THROUGH THE GREAT LAKES
AND NORTHEAST/MID-ATLANTIC. THIS PATTERN WILL PROMOTE A MAJOR
HEATWAVE ACROSS THE SOUTHERN U.S.. MEAN TROUGHING KEEPS
TEMPERATURES AT OR BELOW AVERAGE ACROSS THE EASTERN
PACIFIC/PACIFIC NORTHWEST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS ARE IN REASONABLY GOOD AGREEMENT REGARDING THE 500 MB
PATTERN ACROSS THE CONUS DURING THE MEDIUM RANGE PERIOD. A GENERAL
MODEL BLEND CONSISTING OF MOST OF THE AVAILABLE DETERMINISTIC AND
AI GUIDANCE IS USED ON DAYS 3 AND 4 BEFORE ENSEMBLE MEANS ARE
GRADUALLY INCORPORATED INTO THE BLEND THROUGH THE REST OF THE
PERIOD.
..WEATHER/HAZARDS HIGHLIGHTS
A MAJOR HEAT WAVE IS EXPECTED TO EXPAND BENEATH A GROWING UPPER-
LEVEL RIDGE IN THE CENTRAL/SOUTHERN U.S.. THIS HEAT WAVE WILL
SPREAD FROM THE SOUTHEAST TO THE SOUTHERN PLAINS AND INTO THE
CENTRAL ROCKIES BY THE WEEKEND. HEAT INDICES BETWEEN 105-115 ARE
EXPECTED ACROSS THE SOUTH. TROUGHING IN THE NORTHEAST/MID-ATLANTIC
WILL SUPPORT CONTINUED HOT/MOIST SOUTHERLY FLOW INTO THE FLORIDA
PENINSULA, IN PARTICULAR, WHERE THERE'S A GROWING CONCERN FOR
EXTREME HEAT RISK BEGINNING ON WEDNESDAY AND CONTINUING INTO THE
WEEKEND. NO OVERNIGHT RELIEF FROM HOT TEMPERATURES WILL AFFECT
ANYONE WITHOUT ADEQUATE COOLING/HYDRATION AS WELL AS HEALTH
SYSTEMS, INDUSTRIES AND INFRASTRUCTURE.
SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SPREAD SOUTH
THROUGH THE MISSISSIPPI VALLEY, MIDWEST AND MID- ATLANTIC BEFORE
STALLING OUT OVER THE SOUTH LATE THIS WEEK AND INTO THE WEEKEND.
MEANWHILE, MONSOONAL MOISTURE MAY START TO INCREASE OVER AT LEAST
ARIZONA LATE-WEEK/WEEKEND AS THE UPPER HIGH LIFTS FARTHER NORTH
INTO UTAH/COLORADO. RIDGE AMPLIFICATION MAY ALSO LEAD TO SOME
DOWNSTREAM STRONG CONVECTION FOR THE SOUTHERN ROCKIES/PLAINS GIVEN
SUMMERTIME AIRMASS AND GROWING UPPER DIFFLUENCE/WEAKNESSES.
KEBEDE
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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