Exeter, California Weather Forecast Discussion

464
FXUS66 KHNX 151846
AFDHNX
Area Forecast Discussion
National Weather Service Hanford CA
1146 AM PDT Mon Sep 15 2025
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.KEY MESSAGES...
1. A warming tend will continue into the middle of the week,
with the warmest temperatures Tuesday. Minor chances (less than
30 percent) to exceed 100 degrees Tuesday and Wednesday for
localized areas of the San Joaquin Valley and Mojave Desert.
2. Smoke will continue to linger as the Garnet Fire continues
to burn but with improving conditions; smoke will not be as
thick or widespread as in previous weeks.
3. Chance for showers an thunderstorms late this week as
tropical moisture tracks over the region from the south.
Thursday will bring the greatest chances for storms at 15 to 25
percent, however there is a chance for storms as early as
Wednesday afternoon that may result in dry lightning.
4. There is a Marginal Risk (5 to 15 percent) for Excessive
Rainfall leading to flash flooding on Thursday for Kern County
and the southern Sierra Nevada. There is also a Marginal Risk on
Friday in the Sierra Nevada extending from Yosemite National
Park to Sequoia National Park.
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.DISCUSSION...
High pressure building over central California through Wednesday
will bring about clear conditions with warming temperatures that
will result in afternoon highs up to seven degrees above average
for this time of year. Stagnant air aloft associated with the
high pressure will keep smoke from the Garnet Fire from being
easily dispersed, causing hazy skies to continue for the next
couple of days though not as concentrated as in previous weeks.
A change in conditions is expected in the latter part of this
week as moisture approaches the region from the south. Tropical
storm Mario, presently located in the east Pacific off the coast
of Baja California is projected to phase with a secondary low
pressure system currently centered off the southern California
coast. Cyclonic flow around the secondary low will cause the
moisture from the post-tropical system to track northward into
southern and central California as early as Wednesday afternoon,
however timing of the influx of moisture has been trending later
in recent model runs towards Wednesday night into Thursday. The
nighttime approach of moisture may limit convective development
but still bring chances for showers starting through Kern County
and extending north through Thursday.
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.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.
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.FIRE WEATHER...
Rising temperatures this week will cause a drop in relative
humidities, with widespread minimums 20 to 25 percent through
Wednesday across the San Joaquin Valley and Sierra Nevada; min
RHs 10 to 15 percent are projected for the Mojave Desert. The
approaching moisture tracking over the warmer temperatures and
lower RHs will bring about some risk for dry lightning Wednesday
afternoon should thunderstorms develop during the period.
However, as stated, the main influx of moisture is projected to
move into the region Wednesday night into Thursday which will
improve RHs. Mixing heights for the valley areas will hold
mostly steady at 7000 to 8000 feet ahead of the moisture,
however mixing heights in the Mojave Desert and Kern County
mountains are expected to exceed 10000 feet, which could lead to
plume dominated fire if any develop.
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.AIR QUALITY ISSUES...
None.
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.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.
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.HNX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
public/aviation...McCoy
idss..............Molina
weather.gov/hanford

NWS HNX Office Area Forecast Discussion