735
FXUS66 KHNX 051102
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
402 AM PDT Fri Jul 5 2024


&&

.KEY MESSAGES...

1. A dangerous, long-duration heat wave will continue to impact
Central California throughout the holiday week, the weekend, and
into next week.

2. An Excessive Heat Warning remains in effect through 11 AM
Thursday, July 11th.

3. A Red Flag Warning remains in effect until 12 PM Friday, but
until 6 AM Saturday for southwestern Kern County.

4. The risk of grass fires will continue to increase with
herbaceous fuel loading at or near 120% of normal. A long period
of excessive heat, minimum relative humidities near 15% and poor
overnight relative humidity recovery continues.

&&

.DISCUSSION...

A very strong ridge continues to hold its grip over the
southwest, resulting in high temperatures around 15 degrees
above normal and very poor overnight recovery. This ridge is
currently a more latitudinal orientation, but we move into the
weekend, it will turn and become more longitudinal and the axis
of the ridge will be directly over Central California. This
will lead to a further increase in high temperatures and an
overall increase in the total area of Extreme Heat Risk. Using
probabilities to illustrate this increase, the chance for a high
of 110 degrees or more in the San Joaquin Valley today is
20-45%, whereas the chance for 110 degrees or more for this
weekend is 60-80%.

After the weekend, the movement of the ridge will be dependent
on the movement of Hurricane Beryl. The tropical system is
likely to follow the trough currently over the eastern CONUS and
get absorbed into the main flow, which would slowly pull the
ridge to the east over the next week. This would put the axis
over Arizona and would slowly bring down high temperatures in
the valley. They would still be above normal, just not above 110
degrees as they are forecast this weekend. The models are also
showing a split in the ridge, lasting from Tuesday into next
Friday, resulting in a mini trough over the Californian coast.
If there is enough moisture with it, there is the possibility
for some thunderstorms, though if it continues to be as dry as
it is right now, that would cause it to be breezy in our area.
Keep in mind that this is in the long term forecast, so
confidence is not high and it will more than likely change in
the coming days.

&&


.AVIATION...

MVFR and local IFR visibility due wildfire smoke will continue.
These areas of smoke may increase. Otherwise, VFR conditions
will prevail across the central California interior for the next
24 hours.

&&

.FIRE WEATHER...

A Red Flag Warning remains in effect for the San Joaquin Valley
and the Kern County Mountains until 12 PM today, with a portion
of southwestern Kern County until 6 AM Saturday. This is due to
very low minimum relative humidities near 15%, breezy winds
with gusts up to 20 mph, above normal temperatures, and very dry
fuels, increasing the risk for fast-moving grass fires. The
risk for fire starts has also increased due to the holiday
activities late last night.

The Warning may need to be extended into the Mojave Slopes due
to increased winds with gusts of 20-30 mph later tonight,
paired with minimum relative humidities in the single digits.

&&

.AIR QUALITY ISSUES...
ISSUED:  07/04/2024 10:50
EXPIRES: 07/05/2024 23:59
None.



&&

.CERTAINTY...

The level of certainty for days 1 and 2 is medium.
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 11 PM PDT Thursday for CAZ300>322-
324-332-334>339.
Red Flag Warning until noon PDT today for CAZ579-580-590-591-
596.
Red Flag Warning until 6 AM PDT Saturday for CAZ597.
&&

$$

Public/Aviation..................EW
DSS/PIO/Fire Weather.............VJP

weather.gov/hanford