123
FXUS66 KHNX 231806
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
1106 AM PDT THU JUL 23 2026
KEY MESSAGES
1. EXTREME HEAT WARNING IN EFFECT FOR THE MOJAVE DESERT AND
INDIAN WELLS VALLEY THROUGH MONDAY. MAJOR HEATRISK EXPECTED
WITH AFTERNOON HIGHS 108 TO 112 EACH DAY.
2. A SMALL INCREASE IN MONSOONAL MOISTURE WILL BRING A SLIGHT
CHANCE FOR THUNDERSTORMS ACROSS THE SIERRA NEVADA CREST AGAIN
THIS FRIDAY, BUT THE REST OF THE WEEK INTO NEXT WILL SEE
CHANCES LESS THAN 10%.
3. HIGH PRESSURE OVER THE REGION WILL MAINTAIN TEMPERATURES
NEAR SEASON AVERAGES FOR THE REMAINDER OF CENTRAL CALIFORNIA
BEFORE HOTTER CONDITIONS APPEAR LATE NEXT WEEK.
DISCUSSION
IN RECENT DAYS, AN AREA OF HIGH PRESSURE HAS STATIONED ITSELF
OVER THE GREAT BASIN.FOUR CORNERS REGION, LEADING TO AN INFLUX
OF MONSOON MOISTURE OVER CALIFORNIA AS SATURATED AIR TRACKED
NORTHWARDS FROM MORE TROPICAL AREAS. OVER THE LAST DAY, THE HIGH
HAS SLID SOUTHWARD AND NOW RESIDES OVER NORTH-CENTRAL TEXAS.
OVER THE NEXT 24 TO 48 HOURS, THE SYSTEM IS EXPECTED TO BUILD
WESTWARD INTO THE DESERT SOUTHWEST, CAUSING TEMPERATURES TO RISE
ACROSS THE REGION. THIS AREA WILL INCLUDE PORTIONS OF THE MOJAVE
DESERT AND INDIAN WELLS VALLEY, WHICH HAVE A 60 TO 70 PERCENT
PROBABILITY TO EXCEED 110 DEGREES EACH AFTERNOON THROUGH MONDAY.
MEANWHILE, THERE IS AN 80 TO 90 PERCENT PROBABILITY FOR MORNING
LOWS TO EXCEED 75 DEGREES, OFFERING LITTLE RELIEF FROM THE HEAT
AT NIGHT. THE COMBINATION OF DAILY HIGHS AND LOWS IN THE DESERT
BRINGS A MAJOR RISK FOR HEAT-RELATED ILLNESSES TO MUCH OF THE
POPULATION AND HAS LED TO AN EXTREME HEAT WARNING NOW IN EFFECT
FOR THE AREA THROUGH MONDAY. FOR THE REMAINING AREAS OF CENTRAL
CALIFORNIA, NEAR AVERAGE TEMPERATURES ARE EXPECTED.
LINGERING MOISTURE FROM THE PREVIOUS WEEK WILL HAVE ONE LAST
GASP ON FRIDAY TO DEVELOP INTO SHOWERS WITH A FEW ISOLATED
THUNDERSTORMS ACROSS THE SIERRA NEVADA. THERE IS A 20 TO 35
PERCENT PROBABILITY FOR THUNDERSTORMS ALONG THE CRESTS IN TULARE
AND SOUTHEASTERN FRESNO COUNTY, WITH LOWER CHANCES ACROSS THE
REMAINDER OF THE SIERRA. AFTER FRIDAY, THE PROBABILITIES FOR
CONVECTIVE DEVELOPMENT FALL TO 10 PERCENT OR LESS EACH DAY
THROUGH THE NEXT WEEK.
AS THE HIGH STRENGTHENS OVER THE REGION INTO NEXT WEEK, WARMER
TEMPERATURES AND DRIER CONDITIONS ARE EXPECTED, ESPECIALLY
TOWARDS THE START OF NEXT MONTH. STARTING MONDAY, MINRH VALUES
IN THE SAN JOAQUIN VALLEY AND SIERRA NEVADA WILL FALL TO 15 TO
20 PERCENT, WITH VALUES IN THE MOJAVE DESERT AROUND 10 PERCENT
AT MOST. THE AFOREMENTIONED HIGH BUILDING OVER THE REGION IN
THE LATE WEEK BRINGS A 50 TO 60 PERCENT PROBABILITY FOR
AFTERNOON HIGHS TO EXCEED 105 DEGREES IN THE SAN JOAQUIN VALLEY
BEGINNING NEXT FRIDAY.
AVIATION
A 5-10% CHANCE OF AFTERNOON THUNDERSTORMS ACROSS THE SIERRA NEVADA
CREST FROM 21Z THU THROUGH 03Z FRIDAY. OTHERWISE, VFR CONDITIONS
WILL PREVAIL IN THE SAN JOAQUIN VALLEY FOR THE NEXT 24 HOURS.
AIR QUALITY ISSUES
NONE.
CERTAINTY
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.HTML FOR ADDITIONAL INFORMATION
AND/OR TO PROVIDE FEEDBACK.
HNX WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING UNTIL 9 PM PDT MONDAY FOR CAZ337-339.
PUBLIC/AVIATION...MCCOY
WEATHER.GOV/HANFORD
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