810
FXUS66 KHNX 070940
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
240 AM PDT Sun Jul 7 2024

.KEY MESSAGES...

1. A long-duration, rare, heat wave with an Extreme HeatRisk
through late this week will have many impacts on all of our
citizens and all sectors of the community.

2. An Excessive Heat Warning remains in effect until Saturday.
A Heat Advisory remains in effect for the Sierra Nevada through
Monday at 10 AM, and Yosemite NP through Wednesday at 10 AM.

3. A Red Flag Warning remains in effect for the Kern County
Mountains and the Mojave Desert Slopes until 6 AM Monday.

4. The high risk of grass fires will continue with herbaceous
fuel loading at or near 120% of normal exhibiting behavior
typically not experienced with such low wind speeds.

&&

.DISCUSSION...A large upper ridge remains parked over CA
maintaining status quo for our area. Unfortunately, this means
another day of widespread dangerous heat across much of our area
with many locations once again expected to have record high
temperatures.

The ridge is progged to slide eastward slightly on Monday and
Tuesday as the ridge will be drawn eastward by Hurricane Beryl
as it moves into southeast Texas. The impact for this will be a
slight cooling trend for our although dangerous heat and
noticable heat impacts will continue for most of our area.

Medium range ensemble means are showing the ridge building back
into CA on Wednesday and Thursday which will maintain the
dangerous heat conditions across most of our area for much of
the week ahead before a trough approaches the PAC NW and Norcal
next weekend and finally displaces the upper ridge. This will
likely result in a more noticable cooling trend for our area
although afternoon highs will remain in the triple digits across
the San Joaquin Valley and Kern County Deserts. However, the
probability for dangerous heat will become less likely. Latest
NBM probabilistic guidance is indicating that by next Saturday
the PoE of 105 DEG F in the San Joaquin Valley lowers to 35 to
65 percent and by next Sunday to 20 to 45 percent.

The approaching trough might provide for enough instability for
some isolated afternoon thunderstorms near the Sierra Crest in
Tulare County by next weekend and also bring about enough of an
increase in surface p-grads for breezy to windy conditions in
portions of the Kern County Mountains and Deserts by Saturday
afternoon.

&&

.AVIATION...Areas of MVFR and local IFR visibility due
wildfire smoke will continue over the Sierra foothills and
valley facing slopes of the Sierra Nevada. Otherwise, VFR
conditions will prevail across the central CA interior for the
next 24 hours.

&&

.FIRE WEATHER...Extreme heat will continue with very low
afternoon humidity levels around 10-15% in the Valley and under
10% for the desert. Then even the High Sierra is witnessing
mainly teens with some valleys dipping into the single digits.
Overnight recoveries will be poor for the elevated areas of the
Western Hills, Sierra, and Kern County Mountains. The desert
will recover only to 15 to 20 percent. In the San Joaquin Valley
40 to 60% fair recovery has the highest probability.

The RH trend for the week ahead is flat with poor recoveries
and sub 20 percent afternoon minimum RH through late this week.
The wind will remain fairly light with the exception being the
Mojave Slopes with periods of elevated wind that may require
more fire weather highlights.

&&

.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...
Excessive Heat Warning until 3 AM PDT Saturday for CAZ300>322-
324-325-332-334>339.
Red Flag Warning until 6 AM PDT Monday for CAZ596-597.
Heat Advisory until 10 AM PDT Wednesday for CAZ323.
Heat Advisory until 10 AM PDT Monday for CAZ326>331-333.

&&

$$

public/.aviation...DAS
idss...Proton

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