688
FXUS66 KHNX 011007
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
307 AM PDT Sat Jun 1 2024

&&

.KEY MESSAGES...

1. Seven to ten degrees above normal temperatures will continue
this afternoon.

2. Gusty west winds will develop tonight through Sunday morning
for the Mojave Desert Slopes.

3. Following a cool down early next week, a more significant
warming trend will take place next week with probabilities of
exceeding 105 degrees ranging from 35 to 65 percent for most of
the San Joaquin Valley on Wednesday and Thursday. Excessive Heat
Watch has been issued for the event. The heat watch has been
extended into the Kern County Desert for Wednesday and Thursday
with probabilities exceeding 105 ranging from 45 to 95 percent.

4. The anticipated heat for later next week could lead to
increased snowmelt from the Sierra Nevada with colder and higher
flows along rivers and waterways.

&&

.DISCUSSION...

An upper low over the Gulf of Alaska will continue to swing
troughs across the West Coast through the weekend. Another hot
day today expected with probability of exceedance (PoE) of 95*F
ranging 55 to 65 percent from Fresno south, and 6 to 31 percent
north of Fresno this afternoon.

Tonight has the impacts of the trough are taking over the region
we can expect the Mojave Slope winds to kick up again. The
pressure gradient and cooler air will combine forces producing
advisory level winds for the Highway 58 and Highway 14 corridor.
PoE of 45 mph starting at 8 PM hits 100 percent for the Slopes
and holds in until 6-8 AM. PoE of 60 mph peaks at 30% for the
vicinity of Mojave town site late this evening, however will not
at this time consider the upgrade to high wind warning.

The cooler upper levels will take the PoE of 95*F below five
percent for the San Joaquin Valley for Sunday and Monday. Even
PoE of 90*F on Monday falls to 31 to 56 percent. There is very
little convective energy expected for thunderstorm activity for
the Sierra at this time to bring thunder into the forecast.

Tuesday becomes the transition day as the upper ridge over the
Central Pacific joins forces with the persistent ridge that has
held strong over Mexico for the past few weeks. This brings the
PoE of 95*F for the San Joaquin Valley up to the range of 21 to
51 percent.

Wednesday and Thursday the heat ridge builds in with 500 MB
heights building above 590 DM. This translates into PoE of 105*F
31 to 56 percent on Wednesday and 36 to 56 percent on Thursday
for the San Joaquin Valley. Over in the Kern County Desert
Wednesday and Thursday PoE of 105*F is 41 to 91 percent and
China Lake NAF PoE of 110*F is 21 to 31 percent at the same
time. Extended the Heat Watch into the Kern County Desert on
this run.

Friday into next Saturday brings the ridge to nudge to the east
into the Great Basin as a weakness in the ridge becomes an upper
level low and moves into Southern California. Friday PoE of
105*F continues elevated at this time to 21 to 46 percent and
Saturday falls off to 6 to 16 percent. The main change with this
feature is the introduction of Sierra Thunderstorms and Kern
County Mountains thunderstorms. The Sierra begins the
probabilities on Thursday of 5 to 10 percent for the crests.
Friday and next Saturday 10 to 15 percent for the crests. Next
Saturday the 5 to 10 percent probabilities for the Kern County
Mountains and even Western Hills, Sierra Foothills, and Kern
County Desert hit the 5 percent mark. The upper low over the
region hits that this could happen and will have to be followed
up on as it goes closer.

&&

.AVIATION...VFR conditions will prevail across the central CA
interior over the next 24 hours.

&&

.FIRE WEATHER...

Afternoon heat and relative humidity falling into the teens
along with northerly winds 10 to 15 mph in the San Joaquin
Valley look to continue the threat of any vegetation fires to
continue to be an issue today.

The upcoming heat wave mid to late week will again bring RH
values down into the teens. At this time wind is expected to be
sub 10 mph, however will have to be monitored.

&&

.HYDROLOGY...

The first visit to 60s to 70s for the higher elevations will
bring more snowmelt into the river systems. The increased cold
water flows and temperatures in the lower elevations increasing
into the 100s the threat of cold water hypothermia increases
significantly for the region. The messaging will continue to
this high impact threat. The probabilities of flooding issues
are near zero through the period. Mainly a recreational
enthusiasts impacts with the heat and cold water.

&&

.AIR QUALITY ISSUES...
ISSUED:  05/31/2024 15:53
EXPIRES: 06/01/2024 23:59
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...
Wind Advisory from 5 PM this afternoon to 8 AM PDT Sunday for
CAZ338.
Excessive Heat Watch from Wednesday morning through Thursday
evening for CAZ301>307-309>317-319-321-337-339.
&&

$$

Operations...Proton
IDSS....BSO

weather.gov/hanford