557
FXUS66 KHNX 051736
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
1036 AM PDT FRI SEP 5 2025
KEY MESSAGES
1. THERE IS A SLIGHT CHANCE (5-15%) FOR THUNDERSTORMS THIS
AFTERNOON ALONG THE SIERRA NEVADA CREST, WITH CHANCES FALLING
BELOW 5% TOMORROW AFTERNOON AND REMAINING AT THAT LEVEL THROUGH
THE WEEKEND.
2. THE COOLING TREND IS EXPECTED TO CONTINUE TODAY WITH HIGHS
ACROSS THE REGION APPROACHING NORMAL VALUES FOR THIS TIME OF
YEAR. TEMPERATURES WILL BEGIN TO DIP BELOW NORMAL OVER THE
WEEKEND AND FURTHER STILL INTO EARLY NEXT WEEK.
DISCUSSION
THE LAST, SMALL AMOUNT OF MONSOONAL MOISTURE THAT IS LINGERING
ALONG THE SIERRA NEVADA CREST HAS A 5 TO 15% CHANCE FOR
PRODUCING THUNDERSTORMS THIS AFTERNOON, THOUGH THIS HAS THE
STRONGER LIKELIHOOD OF MAINLY PRODUCING CUMULUS AND A FEW
TOWERING CUMULUS CLOUDS, SIMILAR TO THE PAST COUPLE DAYS. AFTER
TODAY, THE THUNDERSTORM CHANCES FALL FURTHER DOWN TO LESS THAN
5%, WHERE EVEN CUMULUS CLOUDS MAY STRUGGLE TO FORM OVER THE
SIERRAS.
CAUSING THAT DECREASE IN THUNDERSTORM POTENTIAL IS AN INCOMING
TROUGH FROM THE PACIFIC, WHICH IS EXPECTED TO BE STRONGER THAN
WHAT IS NORMALLY SEEN AT THIS TIME OF YEAR. IF THOSE CONDITIONS
MATERIALIZE, THIS TROUGH WILL LEAD TO A FAIRLY SIGNIFICANT
COOLDOWN FOR THE REGION, WITH TEMPERATURES IN THE VALLEY 5 TO
10 DEGREES BELOW NORMAL BY MID NEXT WEEK. HIGHS TODAY ARE
EXPECTED TO BE AROUND NORMAL FOR THIS TIME OF YEAR, AND BECOMING
SLIGHTLY BELOW NORMAL BY THE WEEKEND. LONG TERM MODELS ARE ALSO
SIGNALING THAT THIS COOLDOWN WILL BE SOMEWHAT SHORT LIVED AS
ZONAL FLOW MAY BEGIN TO TAKE OVER BY NEXT WEEKEND IN THE MIDDLE
OF THE MONTH, WHICH WOULD LEAD TO THE RETURN OF NEAR NORMAL TO
ABOVE NORMAL TEMPERATURES.
AVIATION
18Z UPDATE:
VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR
FOR THE NEXT 24 HOURS. THERE IS A 10-15 PERCENT CHANCE OF
THUNDERSTORMS OVER THE SIERRA NEVADA FROM 19Z FRI UNTIL 06Z SAT.
AIR QUALITY ISSUES
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.
HNX WATCHES/WARNINGS/ADVISORIES
NONE.
PUBLIC/AVIATION/FIRE WEATHER...EW
DSS/PIO........................CM
WEATHER.GOV/HANFORD
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page