880
FXUS66 KHNX 042257
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
357 PM PDT FRI JUL 4 2025
UPDATE
AVIATION SECTION UPDATED
KEY MESSAGES
1. TEMPERATURES SLIGHTLY BELOW SEASON NORMALS WILL EXTEND ACROSS
THE REGION TODAY AND SATURDAY BEFORE A GRADUAL WARM UP THROUGH
THE UPCOMING WEEK.
2. LOW RH VALUES 15 TO 25 PERCENT WILL STRETCH ACROSS MUCH OF
THE SAN JOAQUIN VALLEY AND SIERRA NEVADA THIS WEEKEND WITH
VALUES 5 TO 10 PERCENT IN THE MOJAVE DESERT. RH WILL DECREASE
OVER THE REGION LATER IN THE WEEK WITH WARMING TEMPERATURES.
3. BREEZY CONDITIONS IN LOCALIZED AREAS OF THE REGION THIS
AFTERNOON TO EVENING. THERE IS A 40 TO 70 PERCENT CHANCE FOR
WIND GUSTS GREATER THAN 35 MPH IN THE MOJAVE SLOPES AND A 70 TO
90 PERCENT CHANCE FOR 25 MPH ALONG PACHECO PASS AND AT LAKE
ISABELLA.
DISCUSSION
A BROAD AREA OF LOW PRESSURE PASSING THROUGH THE PACIFIC
NORTHWEST REGION IS CAUSING (RELATIVELY) COOLER AIR TO ENTRAIN
OVER CENTRAL CALIFORNIA FROM THE CENTRAL PACIFIC. AS SUCH,
MAXIMUM TEMPERATURES THIS AND TOMORROW AFTERNOON ARE ANTICIPATED
TO BE A FEW DEGREES BELOW THE AVERAGE FOR THESE DATES. IN FACT,
FOR THIS AFTERNOON THERE IS LESS THAN A 10 PERCENT CHANCE FOR
MUCH OF THE SAN JOAQUIN VALLEY TO EXCEED 95 DEGREES BUT WITH
ISOLATED AREAS AT 20 TO 50 PERCENT. THE TROUGH INFLUENCING THE
REGION WILL CAUSE SOME STRONGER WIND GUSTS ACROSS THE REGION
THIS AFTERNOON AND EVENING, PRIMARILY IN NORMALLY-SUCEPTABLE
LOCATIONS SUCH AS PACHECO PASS, LAKE ISABELLA, AND IN THE MOJAVE
DESERT SLOPES. HOWEVER, ALL LOCATIONS ARE EXPECTED TO REMAIN
BELOW ADVISORY CRITERIA.
TO START NEXT WEEK, A WEAK CUTOFF UPPER LOW OFF THE CALIFORNIA
COAST AND AN UPPER HIGH OVER THE FOUR CORNERS WILL COMBINE TO
CAUSE SOUTHWEST FLOW TO DEVELOP OVER THE REGION. THIS WILL
RESULT IN A GRADUAL WARMING TREND THROUGH THE WEEK WITH TYPICAL
MINIMUM RELATIVE HUMIDITY VALUES BETWEEN 15 AND 25 PERCENT,
EXCEPT FOR THE DESERT AREAS WHERE VALUES WILL BE BETWEEN 5 AND
10 PERCENT. IN THE LATTER PART OF THE WEEK, THE AFOREMENTIONED
RIDGE IS EXPECTED TO SLIDE WESTWARD, CENTERING OVER CALIFORNIA.
THE RESULTING PATTERN WILL BRING A STRONGER INCREASE IN
AFTERNOON TEMPERATURES. THERE IS A 50 TO 70 PERCENT CHANCE FOR
MAXIMUM TEMPERATURES GREATER THAN 100 DEGREES BY THURSDAY IN
THE SAN JOAQUIN VALLEY (AND AN 80 TO 90 PERCENT CHANCE FOR
FRIDAY), AND IN ADDITION THERE IS A 20 TO 40 PERCENT CHANCE FOR
105 DEGREES ON FRIDAY. THESE WARMER CONDITIONS WILL SEEP INTO
THE DESERT AREAS AS WELL, ESPECIALLY FOR INYOKERN AND
RIDGECREST, WHERE THERE IS A 40 TO 70 PERCENT CHANCE TO EXCEED
110 DEGREES NEXT THURSDAY THROUGH SUNDAY.
THE WARMER TEMPERATURES WILL CAUSE DRIER CONDITIONS TO DEVELOP,
WITH WIDESPREAD MINRH VALUES BETWEEN 10 AND 20 PERCENT. THESE
VALUES WILL CONTINUE THE RISK FOR GRASS FIRE DEVELOPMENT,
HOWEVER WITH THE SUBSIDING AIR ALOFT, WINDS WILL BE RELATIVELY
LIGHT IN THE VALLEY AREAS, AND MAINLY DIURNAL AND TERRAIN DRIVEN
IN THE FOOTHILL, MOUNTAIN, AND DESERT AREAS.
AVIATION
0Z UPDATE:
VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS ACROSS THE CENTRAL
CALIFORNIA INTERIOR.
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
NONE.
PUBLIC...SM
AVIATION....JPK
WEATHER.GOV/HANFORD
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