277
FXUS66 KHNX 072329
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
329 PM PST SUN DEC 7 2025
UPDATE
KEY MESSAGES
1. FOG AND LOW CLOUDS WILL CONTINUE EACH NIGHT AND MORNING ACROSS
THE SAN JOAQUIN VALLEY INTO THIS WEEK. DENSE FOG WILL ALSO
DEVELOP AT TIMES IN THE LOWER SIERRA FOOTHILLS, COASTAL RANGES,
AND THE GRAPEVINE.
2. A GRADUAL WARMING TREND WILL OCCUR IN THE MOUNTAINS AND
DESERT UNTIL NEXT WEEK, AS THE HIGH PRESSURE PATTERN CONTINUES
OVER THE REGION.
DISCUSSION
CONDITIONS TODAY REMAIN IN A "RINSE AND REPEAT" PATTERN, WITH
LOW CLOUDS SPANNING ACROSS THE SAN JOAQUIN VALLEY AND AREAS OF
FOG AND REDUCED VISIBILITIES IN THE FOOTHILL AREAS WHERE THESE
CLOUDS ENCOUNTER THE LOCAL TERRAIN. THIS PATTERN COMES AS THE
RESULT OF A STRONG TEMPERATURE INVERSION EXTENDING TO 6000 FEET
ABOVE GROUND LEVEL WHICH IS TRAPPING SATURATED AIR BETWEEN 1000
AND 2000 FEET. IN FACT, THE WARMER TEMPERATURES ARE ANOMALOUSLY
WARM FOR THIS TIME OF YEAR, RUNNING AROUND FIVE DEGREES CELSIUS
ABOVE AVERAGE. WITHOUT WARMER TEMPERATURES AND/OR DRIER
CONDITIONS AT THE SURFACE, OR INCREASED WINDS TO MIX OUT THE LOW
CLOUDS, OUR VALLEY STRATUS WILL LOOK TO CONTINUE AT LEAST
THROUGH MIDWEEK.
AS THE MID TO LATE WEEK PERIOD APPROACHES, THE HIGH PRESSURE
RIDGE OVER THE EASTERN PACIFIC DRIVING OUR STABLE CONDITIONS IS
PROJECTED TO SLIDE EASTWARD, BASED ON CURRENT ENSEMBLE
FORECASTS. THIS PATTERN CHANGE IS EXPECTED TO CAUSE INCREASINGLY
ANOMALOUS TEMPERATURES, ESPECIALLY FOR THE SIERRA NEVADA AND
SURROUNDING FOOTHILLS, AND IN THE KERN COUNTY DESERT.
PROBABILISTIC GUIDANCE SHOWS AREAS INCLUDING LAKE ISABELLA,
OAKHURST, AND YOSEMITE VALLEY HAVE MORE THAN A 90 PERCENT
PROBABILITY FOR MAXIMUM TEMPERATURES TO EXCEED 70 DEGREES THIS
COMING FRIDAY, WHEN THESE LOCATIONS AVERAGE 50 TO 60 DEGREES. IT
WILL REMAIN TO BE SEEN WHAT THIS SYSTEM DOES FOR THE SAN
JOAQUIN VALLEY. WARMER TEMPERATURES CAUSED BY THE RIDGE WILL
BRING AFTERNOON HIGHS NEARER TO SEASON AVERAGES, WHICH COULD
LEAD TO CLEARING CONDITIONS DURING THE DAY, HOWEVER THE
SUBSIDENCE ALOFT CAUSED BY THE HIGH PRESSURE WOULD KEEP MOISTURE
TRAPPED IN THE LOWER LEVELS. THESE WARM AND DRY CONDITIONS ARE
LIKELY TO REMAIN INTO THE EXTENDED PERIOD, AS THE CLIMATE
PREDICTION CENTER EXPRESSES A 70 TO 80 PERCENT CHANCE FOR ABOVE
AVERAGE TEMPERATURES AND 33 TO 50 PERCENT CHANCE FOR BELOW
AVERAGE PRECIPITATION.
AVIATION
IFR TO MVFR CEILINGS AND VISIBILITIES ARE EXPECTED TO PREVAIL
FOR MUCH OF THE SAN JOAQUIN VALLEY. THESE CONDITIONS WILL
CONTINUE THROUGH 18Z MONDAY. LIFR CONDITIONS WILL ALSO PERSIST
IN THE COASTAL RANGES, SIERRA FOOTHILLS, AND THE KERN COUNTY
MOUNTAINS DUE TO THE LOW STRATUS DECK. OTHERWISE, VFR CONDITIONS
WILL PREVAIL IN THE SIERRA NEVADA AND IN THE KERN COUNTY
MOUNTAINS AND DESERT OVER THE NEXT 24 HOURS.
AIR QUALITY ISSUES
ISSUED: 12/07/2025 14:17
EXPIRES: 12/08/2025 23:59
ON MONDAY DECEMBER 8 2025, UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO, KERN, MADERA, AND TULARE COUNTIES. FIREPLACE/WOOD STOVE
BURNING STATUS IS: NO BURNING FOR ALL IN FRESNO, KERN, AND
MADERA COUNTIES. NO BURNING UNLESS REGISTERED IN KINGS, MERCED,
AND TULARE COUNTIES. BURNING DISCOURAGED IN KERN (GREATER
FRAZIER PARK AREA) AND SEQUOIA NATIONAL PARK AND FOREST.
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.
HNX WATCHES/WARNINGS/ADVISORIES
DENSE FOG ADVISORY UNTIL 11 AM PST MONDAY FOR CAZ300-304-308-
313-316>322-334>336.
PUBLIC...MCCOY
AVIATION....JPK
WEATHER.GOV/HANFORD
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