-- Discussion containing changed information from previous version are highlighted. --
372
FXUS66 KHNX 242254
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
354 PM PDT Mon Jun 24 2024


&&

.KEY MESSAGES...

-- Changed Discussion --
1. Temperatures will be around 10- degrees above average again
on Monday with widespread triple digit highs across the lower
elevations. A Heat Advisory remains in effect through Tuesday
morning.

2. Above average temperatures will continue this week, with 100
degree heat persistent for many locations through Wednesday.

3. There is a 10 to 30 percent probability for thunderstorms
Tuesday afternoon along the Sierra Nevada crest from Yosemite
National Park to Kings Canyon and Sequoia National Park.
-- End Changed Discussion --

&&

.DISCUSSION...

-- Changed Discussion --
An upper level high pressure ridge remains over central
California, with the center currently located over the
southwestern United States. The subsiding air underneath the
ridge is continuing to bring triple digit heat to the San
Joaquin Valley, around ten degrees above seasonal averages for
this time of year. Because of these warmer temperatures, a Heat
Advisory remains in effect through Tuesday morning. Ensemble
guidance from the National Blend of Models expresses a 70 to 80
percent probability to exceed 100 degrees in the San Joaquin
Valley this afternoon, with a 60 to 80 percent probability
Tuesday afternoon; however, the northern San Joaquin Valley,
including Madera and Merced, has a 40 to 60 percent probability
Tuesday.

Moisture from the former tropical system Alberto is being
wrapped around the upper level high, bringing scattered showers
to the San Joaquin Valley from the southwest this afternoon. The
propagating moisture is expected to continue cascading across
central California tomorrow, bringing a chance for thunderstorms
to the Sierra Nevada Tuesday afternoon. Probabilistic guidance
suggests 20 to 30 percent for thunderstorms along the Sierra
crest from Yosemite National Park to Kings Canyon and Sequoia
National Park. Some stronger thunderstorms are possible, with
the major hazards being dangerous cloud to ground lightning,
small hail, and stronger wind gusts near 40 miles per hour.

The aforementioned high pressure system is anticipated to
weaken slightly into the midweek as an upper level trough passes
through the Pacific Northwest region. This will result in a
slight cooling trend across central California through next
weekend. Guidance from the NBM expresses less than a 30 percent
probability for temperatures to exceed 100 degrees each day
through Sunday. This cooling trend will bring temperatures close
to season normals. However, while temperatures may be cooler,
the increased pressure gradient between the trough to the
northwest and the ridge to the southeast will increase winds to
the region. This parameter, coupled with relative humidity below
20 percent, will result in at least a minor risk for grassland
fires across the region.

Cluster analysis points towards another ridge building over our
area into July, with long term probabilities showing at least a
60 percent probability for triple digits across the San Joaquin
Valley beginning July 2nd.
-- End Changed Discussion --

&&


.AVIATION...
-- Changed Discussion --
MVFR conditions possible around scattered showers along the
crest and surrounding foothills of the Sierra Nevada through
02Z. MVFR conditions are possible again Tuesday afternoon along
the Sierra Nevada crest. Otherwise, VFR conditions will prevail
across the central California interior for the next 24 hours.
-- End Changed Discussion --

&&

.AIR QUALITY ISSUES...
-- Changed Discussion --
ISSUED:  06/23/2024 15:54
EXPIRES: 06/24/2024 23:59
None.
-- End Changed Discussion --



&&

.CERTAINTY...

-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 11 AM PDT Tuesday for CAZ300>317-319-321-
332.
&&

$$

public/aviation...SM
IDSS..............EW

weather.gov/hanford