859
FXUS66 KHNX 161107
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
407 AM PDT FRI OCT 16 2026
UPDATE
UPDATED AVIATION SECTION.
KEY MESSAGES
1. RED FLAG WARNING ISSUED FOR THE SIERRA NEVADA ABOVE 4000 FEET
DUE TO HIGH WINDS AND LOW RELATIVE HUMIDITY THROUGH FRIDAY
EVENING.
2. WIND ADVISORY HAS BEEN ISSUED FOR THE MOJAVE DESERT ZONES
THROUGH FRIDAY NIGHT WITH WIND GUSTING UP TO 60 MPH.
3. A WARMING TREND CONTINUES THROUGH THE WEEKEND BEFORE A
COOLDOWN NEXT WEEK.
4. A PATTERN CHANGE MAY BE UPON US EARLY NEXT WEEK AS A
DISTURBANCE CROSSES THE WEST AND INTRODUCES UNSETTLED
CONDITIONS.
DISCUSSION
WE HAVE A RED FLAG WARNING OUT TONIGHT INTO TOMORROW. WE HAVE A
RETROGRADING CUTOFF LOW MOVING WEST OVER THE NEXT FEW HOURS,
WHICH SLIDES UNDER THE RIDGE OF HIGH PRESSURE WHICH FORMS A REX
BLOCK AND CAUSES A BIG RELATIONSHIP ISSUE. AND THAT ISSUE IS
THE WINDS WILL INCREASE OVERNIGHT FROM THE EAST OVER THE SIERRA
CREST AND MOJAVE DESERT ALONG WITH LOWER MINIMUM RH VALUES
COUPLED WITH THE WARMING TEMPERATURES FROM THE RIDGE. THE RESULT
IS A RED FLAG WARNING THROUGH FRIDAY NIGHT DUE TO THE
COMBINATION WHICH ALREADY HAS STARTED SOME FIRES IN SOCAL ON
THURSDAY. MINIMUM RH VALUES ARE EXPECTED TO BE IN THE TEENS
ACROSS THE ENTIRE AREA TOMORROW. THERE IS A 10 PERCENT CHANCE OF
25 MPH GUSTS ALONG THE FOOTHILLS BUT A 20 TO 40 PERCENT CHANCE
OF 35 MPH GUSTS ALONG THE CREST OF THE SIERRA NEVADA.
LUCKILY, THE REX BLOCK WEAKENS SIGNIFICANTLY ON SATURDAY, AS THE
RIDGE SLIDES OUT. TEMPERATURES REMAIN WARM BUT THE WINDS FINALLY
DIE DOWN FOR THE TIME BEING. SUNDAY BRINGS A SHORTWAVE TROUGH
WHICH WILL PICK UP THE CUTOFF LOW AND LIFT OUT ON MONDAY.
HOWEVER, THINGS GET EVEN SPICIER AS WE HAVE A STRONGER TROUGH
SLIDE IN LATE ON MONDAY THROUGH THURSDAY. THIS TROUGH BRINGS
COOLER TEMPERATURES AS WE GO FROM A 55 TO 85 PERCENT CHANCE OF
80S IN THE VALLEY SOUTH OF MERCED ON MONDAY TO A 35 TO 50
PERCENT CHANCE OF REACHING 70 ON TUESDAY. THE PROBABILITIES
CONTINUE TO LOWER ON WEDNESDAY WITH A 30 TO 35 PERCENT CHANCE OF
HITTING 70 BEFORE GOING BACK UP TO 45 TO 60 PERCENT ON NEXT
THURSDAY AND FRIDAY. WINDS ALSO PICK UP MONDAY AND TUESDAY IN
THE MOJAVE SLOPES AND DESERT DUE TO THIS BIGGER TROUGH.
THIS BIG PATTERN CHANGE ALSO BRINGS RAIN TO THE AREA. TUESDAY
HAS A 5 TO 15 PERCENT CHANCE OF A TENTH OF AN INCH BEFORE
INCREASING TO 35 TO 45 PERCENT ON WEDNESDAY. THURSDAY ALSO LOOKS
TO HAVE A 20 TO 30 PERCENT CHANCE OF A TENTH OF AN INCH OF
RAIN. THE CPC HAS A 50 TO 60 PERCENT CHANCE OF ABOVE AVERAGE
PRECIPITATION IN THE 6-10 DAY OUTLOOK THANKS TO THIS TROUGH
ALONG WITH A 33 TO 50 PERCENT CHANCE OF BELOW AVERAGE
PRECIPITATION. HOWEVER, THE 8-14 DAY CPC OUTLOOK SHOWS A CHANGE
TO NEAR NORMAL TEMPERATURES EXCEPT A 33 TO 40 PERCENT CHANCE OF
ABOVE AVERAGE TEMPERATURES ALONG THE WEST SIDE AND A 33 TO 40
PERCENT CHANCE OF BELOW AVERAGE PRECIPITATION FOR MOST OF THE
VALLEY TRANSITION TO NEAR NORMAL ALONG THE SIERRA NEVADA AND
KERN COUNTY.
AVIATION
VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS.
FIRE WEATHER
RED FLAG WARNING IN EFFECT UNTIL 10 PM FRIDAY EVENING FOR THE
SIERRA NEVADA, TEHACHAPI, AND SAN EMIGDIO MOUNTAINS ABOVE 4,000
FEET DUE TO STRONG WINDS FROM THE EAST AND LOW HUMIDITY.
CONFIDENCE FOR EASTERLY GUSTS EXCEEDING 40 MPH IS HIGHEST
(70-90 PERCENT CHANCE) TONIGHT INTO FRIDAY MORNING, THOUGH
ISOLATED AREAS WILL EXPERIENCE GUSTS THIS FAST THROUGH THE
ENTIRE WARNED PERIOD. MINIMUM RELATIVE HUMIDITY FRIDAY EXPECTED
BETWEEN 15-25 PERCENT IN THE WARNED AREAS, WITH DRYER AREAS AS
LOW AS 10 PERCENT.
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
WIND ADVISORY UNTIL 10 PM PDT THIS EVENING FOR CAZ337>339.
RED FLAG WARNING UNTIL 10 PM PDT THIS EVENING FOR CAZ592>597.
PUBLIC...JPK
AVIATION....EW
WEATHER.GOV/HANFORD
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