538
FXUS66 KHNX 131800
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
1100 AM PDT Sun Jul 13 2025


.KEY MESSAGES...
1. A Heat Advisory has been issued for the San Joaquin Valley
an Sierra Nevada Foothills through early next week. 20 to 60
percent chance for greater than 103 degrees in the Valley today
and Monday; 40 to 70 percent chance for Foothill areas to
exceed 100 degrees.

2. Low RH values 15 to 25 percent will stretch across much of
the San Joaquin Valley and Sierra Nevada with values 5 to 10
percent in the Mojave Desert early this week. RH will increase
over the region later in the week with cooling temperatures.

3. 60 to 100 percent chance or temperatures to exceed 105
degrees for much of the Kern Desert over the weekend; 50 to 80
percent chance for Inyokern and Ridgecrest to exceed 110 on
Sunday and Monday.

&&

.DISCUSSION...
Heat-wave continues across the region as afternoon highs are
expected to reach back into triple digit range. While 24 hour
change in temperatures is running cooler this morning, the
current trend will still lead toward triple digit temperatures
being reached. Therefore, will expect afternoon highs across the
San Joaquin Valley to fall just within the 100 degree mark.
With the high pressure dome still overhead, smoke from area
wildfires has filtered into the region and will affect the
afternoon temperatures. Ensemble Probability of Exceedance (PoE)
of reaching triple digits shows this effect as favors 100
degrees over 105 degrees this afternoon. The ridge overhead will
also keep winds light and the atmosphere dry. A weak
disturbance cutting through the area (along with an area of
weakness centered over Baja California) on Tuesday/Wednesday
will allow the flow aloft to push monsoonal moisture northward.
The limited moisture along with weak dynamics will support cloud
development over the Sierra Nevada and a very slight chance of
showers on Tuesday. Otherwise, disturbance will help to knock-
down temperatures for the remainder of the period.

High confidence is still be observed with the current heat-wave
as ensemble Probability of Exceedance (PoE) of reaching 103
degrees across the San Joaquin Valley with percentages in the
50%-80% range through Monday. While Tuesday still shows a range
of 50%-80%, the PoE for those percentage are for afternoon highs
reaching 100 degrees. Therefore, will maintain the Heat
Advisory through Tuesday with high confidence that Wednesday
will transition toward below triple digit heat. By mid-week, PoE
of reaching 100 degrees falls below 30%, which translates into
high in the 90s for the remainder of the period.

With the Tuesday to Wednesday time frame as a transitional
period from triple digits to 90s, winds will be on the increase.
PoE of reaching wind speeds of 40 mph will favor the wind-prone
areas of Kern County. Current PoE of 40 mph winds are in the
range of 40%-60% over the Mojave Slopes with a few spots
reaching PoE of 90%. Will monitor the situation for any possible
messaging on this Day 3 to Day 4 event. Again, ensemble do
attempt to push monsoonal moisture northward toward the Sierra
Nevada this week. Yet, with the disturbance riding over the Baja
Cal area of weakness, northward progression of moisture will be
limited as main area of moisture pushes more into Utah/Nevada
than California.

&&

.AVIATION...
18Z Update:

VFR conditions will prevail for the next 24 hours across the Central
California Interior.

&&

.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...
Heat Advisory until 11 PM PDT Tuesday for CAZ300>322-324-325-
332.

&&

$$

Public/Aviation....Molina/SM

weather.gov/hanford