591
FXUS66 KHNX 220556
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
1056 PM PDT MON SEP 21 2026
KEY MESSAGES
1. MINOR HEAT RISK THROUGH TUESDAY AS TEMPERATURES REMAIN AT
OR BELOW SEASONAL NORMAL VALUES.
2. A WARMING TREND IN TEMPERATURES STARTS ON WEDNESDAY AS THE
REGION WILL SEE THE RETURN OF HEAT DURING THE LATTER PART OF THE
PERIOD. THURSDAY LOOKS TO BE THE HOTTEST DAY WITH A GREATER
THAN 70% CHANCE OF A MODERATE HEAT RISK.
DISCUSSION
THE CUT-OFF LOW PRESSURE SYSTEM THAT DROVE TODAY'S MOUNTAINOUS
THUNDERSTORMS WILL BE MOVING EAST THROUGH TOMORROW, LEAVING OUR
AREA ON THE LEESIDE OF ITS AXIS. THIS WILL CAUSE THUNDERSTORM
CHANCES TO FALL OFF A CLIFF AS DRIER AIR TAKES OVER.
TEMPERATURES ARE ALSO EXPECTED TO A FEW DEGREES MAINLY DUE TO
THE LACK OF CLOUD COVER CAUSED BY THIS DRIER AIR.
AS THIS CUT-OFF REJOINS THE LARGER PATTERN, A RIDGE IS EXPECTED
TO BUILD IN FROM THE EAST, LEADING TO A CONTINUED RISE IN
TEMPERATURES FROM WEDNESDAY INTO THURSDAY, THE LATTER OF WHICH
LOOKS TO BE THE HOTTEST DAY IN THIS UPCOMING WEEK. VALLEY HIGHS
ON THAT DAY ARE EXPECTED TO BE IN THE UPPER 90'S, WITH THE
SOUTHWEST SIDE OF THE VALLEY SEEING A 40-60% CHANCE FOR TRIPLE
DIGITS IN THE AFTERNOON WITH THE REST OF THE VALLEY AT 15% OR
LESS. THURSDAY WILL ALSO SEE AT LEAST A 70% CHANCE FOR MODERATE
HEAT RISK, WHICH AFFECTS THE MORE SENSITIVE PEOPLE AMONG THE
POPULATION, SUCH AS ELDERLY PEOPLE, CHILDREN, AND THOSE WITH
CHRONIC ILLNESSES.
THANKFULLY, THIS HEAT WILL BE SHORT LIVED, AS THE RIDGE IS
PUSHED BACK EAST BY AN INCOMING TROUGH MOVING THROUGH THE
PACIFIC NORTHWEST, REDUCING 500MB HEIGHTS AND BRINGING
TEMPERATURES BACK DOWN TO AROUND NORMAL BY SATURDAY. SLIGHTLY
BELOW NORMAL TEMPERATURES ARE EXPECTED BY SUNDAY INTO MONDAY OF
NEXT WEEK. TYPICAL OF THE TRANSITIONAL SEASON, THIS TEMPERATURE
ROLLERCOASTER IS EXPECTED TO CONTINUE THROUGH NEXT WEEK AS
TROUGHS ARE ABLE TO DIG FURTHER SOUTH AND RIDGES BECOME LESS
ABLE TO PRODUCE SUMMER-LIKE CONDITIONS DUE TO THE REDUCED AMOUNT
OF SUNLIGHT IN THE DAY. LOOKING TO THE LONG TERM FORECAST, THE
CLIMATE PREDICTION CENTER HAS OUR CWA UNDER THE LEANING TO LIKELY
ABOVE NORMAL CATEGORY FOR TEMPERATURES FOR BOTH THE 6 TO 10 DAY
AND 8 TO 14 DAY OUTLOOKS (NORMAL BEING IN THE MID TO UPPER 80'S
FOR THIS TIME OF YEAR), SUGGESTING A RIDGE MAY BUILD OVER
CENTRAL CALIFORNIA AGAIN.
AVIATION
MVFR VISIBILITY DUE TO SMOKE IN THE VICINITY OF THE DOME FIRE IN
YOSEMITE NP THROUGH AT LEAST THIS EVENING. OTHERWISE, VFR
CONDITIONS PREVAILING FOR THE NEXT 24 HOURS.
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
LAKE WIND ADVISORY UNTIL 5 AM PDT TUESDAY FOR CAZ300.
EW
WEATHER.GOV/HANFORD
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page