776
FXUS66 KHNX 181945
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
1245 PM PDT Mon Aug 18 2025


.KEY MESSAGES...
1. The cooling trend is expected to continue until Monday, and
both the Central Valley and Kern County desert will continue to
see a Minor Heat Risk through Tuesday.

2. A significant warming trend returns by the middle of the
week with triple digit heat in the warmest locations. The
potential for Major Heat Risk returns by Thursday in the Kern
County desert and enters into the Central Valley by Friday. An
Extreme Heat Watch has been issued for these areas.

3. Chances for isolated mountain and desert thunderstorms are
in store Friday into this weekend.

4. Elevated fire risk with minimum relative humidity expected
to be less than 10 percent in the Mojave Desert and Kern County
mountains with breezy winds in the afternoon to evening. A Fire
Weather Watch for low humidity and locally breezy winds has
been issued for the Ft Tejon area from Wednesday until Saturday.

&&

.DISCUSSION...
One more mild day is expected today with below average highs.
Highs will remain in the 90`s at the warmest locations in our
forecast area, although the hottest spots remain towards the
Indian Wells Valley with temperatures near to just above the
century mark. A dry southwest flow and upper-level trough over
the Pacific Northwest will allow for mainly clear skies except
for some cumulus cloud buildups over the Sierra. A hotter and
more active pattern is in store later this week into the
weekend.

By Wednesday, widespread triple digit heat returns to the
desert, while triple digits return to the Central Valley by
Thursday as high pressure strengthens over the Desert Southwest
and retrogrades into our area. Further heating will occur
Friday into next weekend, prompting a Major Heat Risk for both
the Central Valley and Kern County desert (which begins as
early as Thursday in this particular region). There remains
some uncertainty regarding the desert heat could be an influx of
monsoonal moisture which might mitigate some heating, although
there is a high probability (60-90 percent) of highs at least
105 degrees starting Thursday. Overnight lows will be a concern
in many desert locations, as well as urban areas in the San
Joaquin Valley. Many San Joaquin Valley locations will
potentially see the hottest temperatures this year so far, and
the chances for highs to reach at least 105 degrees remain at
about 30-60 percent by Friday. We issued Extreme Heat Watches
for both the valley and desert, as well as the Kern River canyon
and towards Lake Isabella for Friday until Sunday morning, but
it begins on Thursday in the Kern County desert. In addition, a
Fire Weather Watch was issued for the Ft Tejon area due to the
combination of locally breezy winds, dry fuels, and low
humidity from Wednesday morning until Saturday evening. Showers
and thunderstorms will also arrive to the region by Friday and
impact both the mountains and desert; this threat lasts into the
weekend. Main impacts will be isolated dry lightning and gusty
erratic winds along with increased cloud cover which would aid
in keeping overnight lows warm, especially in the Kern County
mountains and desert.

The latest CPC (Climate Prediction Center) 6-10 temperature
outlook continues to favor above average temperatures at a 50 to
60 percent probability, while the 8-14 day outlook now shows a
slight tilt towards below average temperatures.

&&

.AVIATION...
18Z Update:

VFR conditions are expected in the San Joaquin Valley 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...
Extreme Heat Watch from Thursday morning through Sunday
morning for CAZ337>339.
Extreme Heat Watch from Friday morning through Sunday morning
for CAZ300>316-332.
Fire Weather Watch from Wednesday morning through Saturday
evening for CAZ597.
&&

$$

BSO/EW

weather.gov/hanford