596
FXUS66 KHNX 171833
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
1133 AM PDT Thu Jul 17 2025


.DISCUSSION...


KEY MESSAGES...
1. Cooler afternoon temperatures with a slow warming trend
going into the weekend.

2. Relative Humidity increasing over the region today and into
the weekend.

3. Showers and thunderstorms developing across the Sierra
Nevada Crest with a 10 to 30 percent chance Today through
Saturday.

4. Probability of precipitation amounts of less than a tenth of
an inch (< 0.10 inch) are about 90% with showers or
thunderstorms today, but wetter showers and storms are expected
on Friday with a 40% probability.

5. Slightly cooler temperatures and breezy conditions possible
for the middle of next week, with some fire weather concerns.

DISCUSSION...

The region remains at least partially under the influence of an
upper level ridge over the four corners region. A weak area of
low pressure moving slowly north along the coast of the Baja
Peninsula was allowing for increased precipitable water and
humidities across the valley. Through today and into Friday,
humidities in eastern Kern and into portions of Kings and
western Tulare county may see this RH increase thanks to the
approach of the low along the Baja.

In general, the pattern will allow for similar temperatures as
yesterday with highs this afternoon in the mid 90s as Short-
Range ensemble Probability of Exceedance (PoE) of reaching 100
degrees is less than 10 percent. PoE of reaching 95 degrees
today again is in the 70% to 90% range for areas in and south of
Fresno County allowing for high forecast confidence is seeing
90s this afternoon. With regards to winds, while PoE of reaching
and exceeding 35 mph is low, will see a light afternoon breeze
over the ridges and passes today.

Probability of Thunder percentages remains low today, generally
from 2-8% this afternoon similar to the convection that occurred
on the crests yesterday. An isolated storm may progress farther
west from the crest towards the foothills than occurred
yesterday, but chances again are on the low side. More organized
showers and isolated storms will wait until Friday and into the
weekend associated with the area of weakness/low pressure over
Baja California. As the low progress north into southern
California moisture will surge into the area. Increasing
thunderstorm threats over the Sierra Nevada Crest and light
winds can be expected during the afternoon and evenings Friday
(Probability of Precipitation and Thunder (PoP&T) indicates a
30% chance on Friday) and Saturday with 10-18% probability of
convection though only isolated (10-30%) chances for any storm
to produce more than 0.10" of precipitation.

As previously mentioned, ensemble precip-water analysis shows
higher values overtaking Central California. Yet, uncertainty
still exist on the amount of moisture as convection may remain
on the drier side. Due to the northward push of monsoonal
moisture this week, thunderstorm will be on the drier side and
raising fire weather concerns. Thunderstorms will linger on
Saturday before clear skies develop on Sunday and continue into
early next week.

Along with increased moisture, a slow warming trend through
Sunday with Ensemble PoE of temperatures will see a slow
increase as widespread values struggle to reach 100 degrees
until Saturday. By Saturday, PoE of 100 degrees will only range
from 20% to 60% with the higher end along the West Side of the
San Joaquin Valley. Sunday will see even higher percentages as
confidence increase toward those values.

Ensemble clusters are in good agreement with a trough making
its way onshore by the middle of next week, though one cluster
does persist the ridge over the four corners. This would allow
for two things, one, the warm up through the weekend will be
short-lived as the disturbance cuts into the ridge pattern.
While higher uncertainty exist in the magnitude of cooling and
wind speeds for Monday, will see some change as longer range
ensemble upper-air analysis leans in the direction of
introducing a trough through the Pacific Northwest early to
middle next week. Of note with this would be the potential
noted in the ensembles/clusters for unseasonably breezier
conditions Tuesday and Wednesday which may allow for gusts from
15 to 20mph on the valley floor and increased winds on the
ridge tops and crests during that time frame.

AVIATION... 18Z Update:

VFR conditions will prevail for the next 24 hours across the
Central California Interior. Surface winds will remain northerly
from 5-12kts becoming light and variable after sunrise on Friday.

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...Hatch
aviation....SM

weather.gov/hanford