082
FXUS66 KHNX 310554
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
344 PM PDT SAT AUG 30 2025
UPDATE
UPDATED AVIATION SECTION.
KEY MESSAGES
1. WARM TREND IN TEMPERATURES AS CHANCES FOR TRIPLE-DIGITS
INCREASES TO NEAR 80 PERCENT ON MONDAY AND TUESDAY. HIGH CHANCES
FOR TRIPLE-DIGITS WILL CONTINUE THROUGH MID-WEEK.
2. A SLIGHT CHANCE (10 PERCENT OR LESS) FOR THUNDERSTORMS OVER
THE SIERRA NEVADA AND FOOTHILLS THIS WEEKEND.
3. MARGINAL (AT LEAST 5 PERCENT) RISK OF FLOODING IN THE VERY
HIGH ELEVATIONS OF THE SIERRA NEVADA DUE TO THE INCREASING
POTENTIAL FOR THUNDERSTORMS.
DISCUSSION
HIGH PRESSURE RIDGE NOW THE DOMINATE FEATURE OVER THE WEST AS
TEMPERATURES CONTINUE TO WARM. THE RIDGE OF HIGH PRESSURE IS
SHOWING SIGNS OF AMPLIFICATION AS IT IS EXPECTED TO FORCE A
DISTURBANCE TO RIDE OVER IT INTO EARLY NEXT WEEK. 24-HOUR TREND
IN TEMPERATURES IS SHOWING POSITIVE GAINS OF 2 TO 5 DEGREES OVER
LATE MORNING ON FRIDAY. WHILE THE SAN JOAQUIN VALLEY HAS THE
POTENTIAL OF REACHING TRIPLE DIGITS TODAY, THE PROBABILITY OF
EXCEEDANCE (POE) OF REACHING 100 DEGREES IS STILL IN THE 40 TO
60 PERCENT RANGE. THEREFORE, WIDESPREAD TRIPLES ARE MORE LIKELY
ON SUNDAY WHEN POE FALLS IN THE 60 TO 80 PERCENT RANGE. FURTHER
AMPLIFICATION OF THE RIDGE WILL ALLOW FOR HIGHS WELL INTO THE
TRIPLE DIGIT RANGE AS AFTERNOON MAX TEMPERATURES REACH FOR
VALUES OF 103 TO 105 DEGREES ON MONDAY THROUGH WEDNESDAY.
ENSEMBLE MOISTURE ANALYSIS IS SHOWING A RETURN OF THE MONSOONAL
THAT IS CURRENTLY BEING SUPPRESSED UNDER THE RIDGE PATTERN.
ONCE THE RIDGE IS SHIFTED BY THE OFF-SHORE DISTURBANCES, A
SOUTHERLY FLOW WILL ALLOW FOR A NORTHWARD SURGE OF MOISTURE THAT
WILL SEE ADDITIONAL SOURCES OF MOISTURE INTRODUCED FROM THE
TROPICS LATER IN THE WEEK. ENSEMBLE UPPER-AIR ANALYSIS SHOWS A
WEAK DISTURBANCE AIMING AT THE BAY-AREA AS THE FLOW BECOMES MORE
SOUTHWESTERLY TO SOUTHEASTERLY. THEREFORE, BY TUESDAY,
PROBABILITY OF MEASURABLE PRECIPITATION (POP) ALONG WITH
INSTABILITY ANALYSIS SHOWS INCREASING PERCENTAGES AS SIGNIFICANT
MOISTURE HAS THE POTENTIAL OF ENTERING THE REGION. WITH POP
VALUES REACHING 40 TO 50 PERCENT, WILL EVALUATE IF THUNDERSTORMS
HAVE THE CAPACITY OF INTRODUCING HEAVY RAIN AS GUIDANCE SHOWS
PERCENTAGES REACHING AT LEAST 5 PERCENT OF MEETING EXCESSIVE
PRECIPITATION CRITERIA ON TUESDAY AND WEDNESDAY ACROSS THE
SIERRA NEVADA AND THE MOUNTAINS AND DESERT OF KERN COUNTY.
THE RIDGE PATTERN IS SHIFTED EAST STARTING ON FRIDAY AS THE
PROBABILITIES OF COOLING AND DRYING INCREASE ACROSS CENTRAL
CALIFORNIA. THURSDAY WILL BE A PERIOD OF TRANSITION AS THE HEAT
AND MOISTURE LINGER AS THE SIGNIFICANT RANGES OF TUESDAY AND
WEDNESDAY IN TERMS OF TEMPERATURES AND MOISTURE.
AVIATION
06Z UPDATE:
VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA
INTERIOR FOR THE NEXT 24 HOURS. LESS THAN 10% CHANCE OF SIERRA
CREST THUNDERSTORMS DURING THE PERIOD.
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...MOLINA
AVIATION....BSO/MCCOY
WEATHER.GOV/HANFORD
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