831
FXUS66 KHNX 280535
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
1035 PM PDT THU MAR 27 2025
UPDATE
AVIATION SECTION UPDATED.
AVIATION
06Z UPDATE:
VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL ACROSS
THE CENTRAL CA INTERIOR FOR THE NEXT 24 HOURS.
AIR QUALITY ISSUES
ISSUED: 03/27/2025 14:36
EXPIRES: 03/28/2025 23:59
NONE.
PREV DISCUSSION
/ISSUED 525 PM PDT THU MAR 27 2025/
UPDATE...
AIR QUALITY AND AVIATION UPDATES
KEY MESSAGES...
1. LIGHT PRECIPITATION IS POSSIBLE IN THE CENTRAL SIERRA NEVADA
AND ALONG THE SIERRA FOOTHILLS TODAY INTO TOMORROW. THERE IS A
50 TO 80 PERCENT CHANCE FOR GREATER THAN ONE TENTH OF AN INCH IN
THESE AREAS BY FRIDAY MORNING.
2. STRONG WIND GUSTS WILL PROPAGATE IN THE MOJAVE DESERT SLOPES
TODAY THROUGH SATURDAY. A WIND ADVISORY HAS BEEN ISSUED FOR THIS
AREA DUE TO EXPECTED WINDS 30 TO 40 MPH WITH GUSTS TO 60 MPH.
3. ABOVE NORMAL TEMPERATURES THIS AFTERNOON WILL GIVE WAY TO
NEAR NORMAL TEMPERATURES TOMORROW WHICH WILL LAST THROUGH THE
NEXT WEEK.
4. THERE IS POTENTIAL FOR A SYSTEM TO MOVE THROUGH THE REGION
NEXT WEEK, HOWEVER THERE REMAINS A LARGE AMOUNT OF UNCERTAINTY
IN ASSOCIATED PRECIPITATION TOTALS.
DISCUSSION...
A MODEST LOW PRESSURE SYSTEM CURRENTLY SITS OFF THE COAST OF
THE PACIFIC NORTHWEST REGION, DRIVING MOISTURE ALOFT OVER
CENTRAL CALIFORNIA FROM THE WEST TO SOUTHWEST. CLOUDIER
CONDITIONS HAVE BEEN OBSERVED THIS MORNING AS A RESULT,
ESPECIALLY ALONG THE WEST WIDE HILLS WHERE THE DEEPENING MARIN
LAYER HAS OVERCOME THE COASTAL RANGE. SKIES WILL GRADUALLY CLEAR
ACROSS THE SAN JOAQUIN VALLEY THROUGH THE MORNING AND EARLY
AFTERNOON AS SURFACE TEMPERATURES BEGIN TO WARM. HOWEVER AS THE
SYSTEM TRACKS CLOSER TO THE PACIFIC COAST LATER THIS AFTERNOON
TO EVENING, ANOTHER ROUND OF INCREASED MOISTURE IS ANTICIPATED
TO MAKE ITS WAY OVER CENTRAL CALIFORNIA. WHILE MOST OF THE AREA
WILL ONLY SEE AN INCREASE IN CLOUD COVER, THERE ARE CHANCES FOR
LIGHT PRECIPITATION IN THE NORTHERN SAN JOAQUIN VALLEY, CENTRAL
SIERRA NEVADA, AND ALONG THE FOOTHILLS.
THERE IS A 40 TO 60 PERCENT CHANCE FOR MEASURABLE RAINFALL IN
MADERA, MERCED, AND FRESNO COUNTIES THROUGH 5 AM TOMORROW
MORNING, MAINLY ON THE EASTERN SIDE OF THE VALLEY. MODERATE LOW
LEVEL WINDS CONTINUING FROM THE WEST WILL CREATE A RAIN
SHADOWING EFFECT FOR THE WESTERN VALLEY AREAS. HOWEVER, AS
MOISTURE BANKS UP AGAINST THE SIERRA NEVADA DUE TO THE REGION’S
TOPOGRAPHY, THERE IS AN INCREASED CHANCE FOR PRECIPITATION FOR
THE FOOTHILL COMMUNITIES. ACROSS THE NEXT 24 HOURS, THERE IS A
50 TO 80 PERCENT CHANCE FOR ONE TENTH OF AN INCH OR MORE
INCLUDING, BUT NOT LIMITED TO, OAKHURST, EL PORTAL, CAMP NELSON,
AND ALTA SIERRA. THE AREAS WITH THE GREATEST PROBABILITIES FOR
PRECIPITATION ARE THOSE IN AND AROUND YOSEMITE NATIONAL PARK,
WHICH HAS A 60 TO 100 PERCENT CHANCE FOR ONE TENTH OF LIQUID
PRECIPITATION. THOUGH, WITH SNOW LEVELS 7000 TO 7500 FEET, THERE
IS A 30 TO 80 PERCENT CHANCE FOR ACCUMULATED SNOWFALL GREATER
THAN ONE INCH AT THE HIGHER ELEVATIONS.
TEMPERATURES ARE ANTICIPATED TO BE A HANDFUL OF DEGREES ABOVE
NORMAL FOR THIS TIME OF YEAR DUE TO THE FLOW PROPAGATING OUT TO
THE WEST TO SOUTHWEST. THERE IS A 50 TO 80 PERCENT CHANCE FOR
AFTERNOON TEMPERATURES TO EXCEED 75 DEGREES TODAY IN THE SAN
JOAQUIN VALLEY SOUTH OF MADERA COUNTY. A GRADUAL SHIFT TO ZONAL
FLOW IS EXPECTED BEGINNING TOMORROW, WHICH WILL CAUSE
TEMPERATURES TO DECREASE BACK NEAR NORMAL. THESE TEMPERATURES
ARE FAVORABLE TO MAINTAIN INTO NEXT WEEK AS THIS PATTERN
CONTINUES THROUGH THE FORECAST PERIOD.
DUE TO THE NEAR-CONSTANT WESTERLY FLOW THROUGH THE REMAINDER OF
THE WEEK, STRONGER WIND GUSTS ARE EXPECTED IN THE MOJAVE DESERT
SLOPES AND ALONG THE CRESTS OF THE SIERRA NEVADA. THERE IS A 50
TO 80 PERCENT CHANCE FOR WIND GUSTS TO EXCEED 50 MILES PER HOUR
IN THESE AREAS TODAY, WITH THESE PROBABILITIES SHIFTING TO THE
MOJAVE SLOPES FOR FRIDAY AND SATURDAY. A WIND ADVISORY HAS BEEN
ISSUED FOR THE SLOPES DUE TO EXPECTED SUSTAINED WINDS 30 TO 40
MILES PER HOUR WITH GUSTS OF 60 MILES PER HOUR.
IN THE EARLY TO MID PERIOD OF NEXT WEEK, THERE ARE FAVORABLE
INDICATIONS THAT A LOW PRESSURE SYSTEM WILL DROP SOUTH FROM THE
GULF OF ALASKA TO JUST OFF THE COAST OF THE PACIFIC NORTHWEST
REGION. HOWEVER, FROM THERE THE MODELS HAVE A FAIR DEGREE OF
UNCERTAINTY AS TO THE LOCATION AND INTENSITY OF THIS SYSTEM
MOVING FORWARD. THIS UNCERTAINTY IS BEST EXEMPLIFIED BY THE
DAILY 24 HOUR PRECIPITATION PROBABILITIES FROM THE NATIONAL
BLEND OF MODELS NEXT TUESDAY THROUGH FRIDAY. FOR EACH DAY IN THE
SAN JOAQUIN VALLEY, THE 25TH PERCENTILE EXPRESSES NO
PRECIPITATION OCCURRING. FOR REFERENCE, THE 25TH PERCENTILE
INDICATES A 25 PERCENT CHANCE TO REMAIN BELOW THE INDICATED
VALUE, WITH A 75 PERCENT CHANCE TO EXCEED THE VALUE. THOUGH ON
THE FLIP SIDE, THE 75TH PERCENTILE 24 HOUR PRECIPITATION VALUES
(SPECIFICALLY FOR NEXT THURSDAY) RANGE BETWEEN HALF AND THREE
QUARTERS OF AN INCH IN THE SAN JOAQUIN VALLEY. THE 75TH
PERCENTILE INDICATES A 75% CHANCE TO REMAIN BELOW THESE VALUES,
WITH A 25% CHANCE TO EXCEED THESE VALUES. ALL THIS CONSIDERED,
THERE IS STILL A SIGNIFICANT AMOUNT OF SPREAD IN PRECIPITATION
FOR NEXT WEEK, WHICH ALSO EXTENDS INTO THE FOOTHILLS AND
MOUNTAIN AREAS OF THE SIERRA NEVADA.
AVIATION...
18Z UPDATE:
MVFR TO IFR CONDITIONS DUE TO MOUNTAIN OBSCURING CLOUD COVER ARE
POSSIBLE ALONG THE SIERRA CREST AND IN THE SIERRA FOOTHILLS
UNTIL 12Z. WINDS BECOME WESTERLY 15-25KTS FOR MUCH OF THE SAN
JOAQUIN VALLEY AFTER 21Z THURSDAY. IN ADDITION, WESTERLY WINDS
20-30KTS WITH GUSTS 40-50 KTS EXPECTED TOWARDS THE MOJAVE DESERT
SLOPES IN EASTERN KERN COUNTY. OTHERWISE, VFR CONDITIONS WILL
PREVAIL.
AIR QUALITY ISSUES...
ISSUED: 03/27/2025 14:36
EXPIRES: 03/28/2025 23:59
NONE.
CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
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.
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 5 PM PDT SATURDAY FOR CAZ338.
PUBLIC...JPK
AVIATION....CASTRO
WEATHER.GOV/HANFORD
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page