211
FXUS66 KHNX 171940
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
1240 PM PDT WED SEP 17 2025
KEY MESSAGES
1. 5 TO 10 PERCENT CHANCE OF THUNDERSTORMS IN SOUTHWESTERN KERN
COUNTY TODAY. 10 TO 30 PERCENT CHANCE WIDESPREAD ACROSS THE SAN
JOAQUIN VALLEY, SIERRA NEVADA AND MOJAVE DESERT THURSDAY INTO FRIDAY
MORNING. FOR LATE FRIDAY MORNING UNTIL LATE FRIDAY NIGHT, 10 TO 25
PERCENT CHANCE OF THUNDERSTORMS OVER THE SIERRA NEVADA AND MOJAVE
WITH A 5 TO 15 PERCENT CHANCE IN THE SAN JOAQUIN VALLEY.
2. FLOOD WATCHES IN EFFECT FROM EARLY THURSDAY MORNING THROUGH
LATE FRIDAY NIGHT DUE TO THE THUNDERSTORMS AND HEAVY RAIN FROM
THE REMNANTS OF MARIO.
3. MINOR CHANCES (LESS THAN 30 PERCENT) TO EXCEED 100 DEGREES
WEDNESDAY FOR LOCALIZED AREAS OF THE SAN JOAQUIN VALLEY AND MOJAVE
DESERT. TEMPERATURES WILL COOL THURSDAY INTO THE WEEKEND.
DISCUSSION
SOME MORNING THUNDERSTORMS GREETED SOUTHWESTERN KERN COUNTY THIS
MORNING, HOWEVER, ANOTHER WARM DAY IS IN STORE TODAY. HOWEVER,
THE RIDGE OF HIGH PRESSURE WHICH BROUGHT WARMER TEMPERATURES
YESTERDAY AND TODAY WILL WEAKEN AND MOVE EAST ALLOWING THE
REMNANTS OF POST-TROPICAL CYCLONE MARIO TO PUMP MOISTURE IN OUR
AREA BRINGING THUNDERSTORM CHANCES AND COOLER TEMPERATURES TO
THE AREA. FLOOD WATCHES ARE IN EFFECT FROM THURSDAY MORNING
THROUGH LATE FRIDAY NIGHT DUE TO THE POTENTIAL OF THUNDERSTORMS
ESPECIALLY OVER BURN SCARS COULD PRODUCE FLOODING. THERE IS A
WIDESPREAD 15 TO 30 PERCENT CHANCE OF THUNDERSTORMS ON THURSDAY
FOR MOST OF THE VALLEY, SIERRA NEVADA, AND MOJAVE DESERT.
THIS STORM BRINGS A 35 TO 70 PERCENT CHANCE OF AT LEAST QUARTER
OF AN INCH OF RAIN OR MORE TO THE SAN JOAQUIN VALLEY. FRIDAY HAS
A 10 TO 30 PERCENT CHANCE OF THUNDERSTORMS FOR THE SIERRA NEVADA
AND THE MOJAVE WHILE THE VALLEY HAS A 5 TO 15 PERCENT CHANCE OF
THUNDERSTORMS. SATURDAY AND SUNDAY HAVE 5 TO 15 PERCENT
PROBABILITIES OF THUNDERSTORMS AS THE LOW MOVES WEST. A RIDGE
WILL DEVELOP OVER THE WEEKEND BRINGING TEMPERATURES BACK UP AND
DRIER CONDITIONS. HOWEVER, ENSEMBLES HAVE SOME DISAGREEMENT
ABOUT NEXT WEEK REGARDING THE STRENGTH OF ANOTHER TROUGH.
HOWEVER, PROBABILITIES ALREADY SHOW A 15 TO 30 PERCENT CHANCE OF
AT LEAST QUARTER INCH OF RAIN TO THE VALLEY NEXT TUESDAY WHICH
WILL BE SOMETHING TO MONITOR AFTER FRIDAY.
AVIATION
18Z UPDATE:
VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR
FOR THE NEXT 24 HOURS. AREAS OF DENSE SMOKE ALOFT ALONG THE SIERRA
NEVADA OVER EASTERN FRESNO COUNTY AND NEARBY COUNTIES FROM THE
GARNET FIRE MAY IMPACT VISIBILITY. HOWEVER, THUNDERSTORM CHANCES
INCREASE AFTER 12Z FRIDAY TO 5 TO 15 PERCENT IN KERN COUNTY.
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
FLOOD WATCH FROM LATE TONIGHT THROUGH FRIDAY AFTERNOON FOR
CAZ321-322-331>339.
FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY AFTERNOON
FOR CAZ304>316.
FLOOD WATCH FROM THURSDAY MORNING THROUGH FRIDAY EVENING FOR
CAZ317>320-323>330.
JPK
WEATHER.GOV/HANFORD
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