267
FXUS66 KHNX 180611
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
1111 PM PDT MON AUG 17 2026
KEY MESSAGES
1. TEMPERATURES WILL GRADUALLY WARM THIS WEEK AND RISE BACK TO
AROUND 5 DEGREES ABOVE AVERAGE BY THE MIDDLE OF THE WEEK. THE
TEMPERATURES WILL BACK DOWN FRIDAY INTO THE WEEKEND.
2. BREEZY CONDITIONS TAKE PLACE OVER TYPICAL WIND-PRONE AREAS
INCLUDING SAN LUIS RESERVOIR, LAKE ISABELLA AND THE MOJAVE
DESERT SLOPES THROUGH THIS WEEK.
DISCUSSION
CONTINUED SOUTHWESTERLY FLOW IS PUSHING OVER CENTRAL CALIFORNIA
THIS EVENING AS THE REGION IS CAUGHT BETWEEN TWO DIFFERING
AIR MASS SYSTEMS. A CUT-OFF LOW PRESSURE TROUGH STILL REMAINS
FIRMLY IN PLACE OVER THE EASTERN PACIFIC ALONG WITH A HIGH
PRESSURE RIDGE LOCATED OVER THE SOUTHERN UNITED STATES. THE
LATTER OF THESE AIR MASSES IS EXPECTED TO GRADUALLY SHIFT
WESTWARD THROUGH THE WEEK, BUILDING OVER THE DESERT SOUTHWEST,
WITH INFLUENCES EXTENDING INTO SOUTHERN AND CENTRAL CALIFORNIA.
AS THE HIGH BUILDS IN, TEMPERATURES ARE EXPECTED TO BE ON THE
UPTREND, APPROACHING TRIPLE-DIGITS IN THE CENTRAL VALLEY ON
WEDNESDAY THEN PASSING THIS THRESHOLD ON THURSDAY.
PROBABILITIES FOR 100 DEGREES IN THE LOWER ELEVATIONS IS AROUND
50 TO 60 PERCENT FOR MOST COMMUNITIES ON WEDNESDAY, WHICH
INCREASING TO 70 TO 80 PERCENT ON THURSDAY.
A SLIGHT COOLING TREND WILL SET UP INTO THE WEEKEND, COMING
ABOUT THANKS TO THE AFOREMENTIONED CUTOFF LOW TRACKING INTO THE
PACIFIC NORTHWEST REGION. THE LOW PRESSURE APPEARS TO WIN OUT
OVER THE HIGH, PUSHING THE LATTER BACK EASTWARD INTO THE
SOUTHERN GREAT PLAINS. FOR FRIDAY, THERE IS A 30 TO 40 PERCENT
PROBABILITY FOR TEMPERATURES TO EXCEED 100 DEGREES IN THE VALLEY
AREAS, THEN DECREASES TO 20 TO 30 PERCENT FOR THE WEEKEND. THE
TREND WILL ONLY DROP TEMEPRATURES A HANDFUL OF DEGREES, THOUGH
HIGHS ARE EXPECTED TO RETURN NEAR SEASON AVERAGES. WITH THE
WARMING TREND THROUGH THE BEGINNING OF THIS WEEK, WIDESPREAD
AREAS OF MODERATE HEAT RISK ARE EXPECTED, ESPECIALLY FOR THE SAN
JOAQUIN VALLEY, SIERRA NEVADA FOOTHILLS, AND MOJAVE DESERT. THIS
LEVEL OF HEAT IS TOLERATED BY THE WELL-ACCLIMATED, BUT BRINGS
RISK OF HEAT-RELATED ILLNESSES TO THOSE SENSITIVE TO HEAT, SUCH
AS OLDER ADULTS (65+), INFANTS, ATHLETES, OUTDOOR WORKERS,
THOSE WITHOUT EFFECTIVE COOLING, AND THOSE WITH CHRONIC
DISEASES.
THE WARMER CONDITIONS WILL ALSO RESULT IN LOWER RELATIVE
HUMIDITY VALUES ACROSS THE REGION, ESPECIALLY FOR THE AREAS
LISTED ABOVE WHERE THE TEMPERATURES WILL BE AT THEIR WARMEST.
VALLEY AND SIERRA MINIMUMS ARE EXPECTED BETWEEN 15 AND 25
PERCENT AT THEIR LOWEST POINT MIDWEEK, WITH DESERT VALUES
EXPECTED BETWEEN 10 AND 15 PERCENT. HOWEVER, OVERNIGHT
RECOVERIES WILL BE MODERATE TO GOOD, LARGELY AT 50 TO 60 PERCENT
ACROSS THE LOCAL AREA OUTSIDE OF THE DESERT.
DUE TO HIGH PRESSURE WINNING OUT IN THE EARLY PART OF THIS
WEEK, WINDS WILL MOSTLY RETURN TO BEING LIGHT AND DIURNAL EXCEPT
FOR THE MOST WIND-PRONE LOCATIONS. THESE INCLUDE SAN LUIS
RESERVOIR, LAKE ISABELLA, AND THE MOJAVE DESERT SLOPES IN THE
LEE OF THE TEHACHAPI RANGE.
AVIATION
VFR CONDITIONS WILL PREVAIL 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
NONE.
PUBLIC/AVIATION...MCCOY
WEATHER.GOV/HANFORD
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