June 26, 2023 - National Weather Service Hanford officials report widespread triple digit heat is expected in the San Joaquin Valley and Coastal Range Friday, June 30th, 2023 through at least Monday, July 3rd, 2023.
These two pictures represent high temperatures on Sunday, July 1st, and Monday, July 3rd.
Heat-sensitive groups, such as the elderly, young children, and those with chronic ailments may need assistance to avoid heat-related illnesses.
Area Forecast Discussion
National Weather Service Hanford CA
1209 AM PDT Mon Jun 26 2023
.SYNOPSIS...
Afternoon high temperatures remain below normal for late June
today, but that will quickly change this week as a heat wave
arrives to the region due to high pressure aloft. Afternoon high
temperatures Friday will be about 10 degrees above normal, with
even hotter highs over the weekend. Dangerous heat could extend
beyond the weekend into next week.
&&
.DISCUSSION...
A trough of low pressure progresses eastward into Central
California today, continuing the cooler than normal temperature
trend we have seen lately. Some lift and instability with this
trough may lead to a thunderstorm or two over the Sierra Nevada
this afternoon. Onshore pressure gradients also pick up, so breezy
conditions through the wind prone portions of Central California
are forecast to occur this evening.
As the trough begins to lose influence through the region
tomorrow, afternoon highs begin to tick upwards, with afternoon
highs around 90*F forecast. The trend upward in afternoon highs
progresses on Wednesday, with highs in the low 90s. Afternoon
highs increase more rapidly on Thursday as high pressure in the
Eastern Pacific builds. Highs just shy of 100*F are currently
forecast by the NBM on Thursday.
The most impactful heat begins on Friday with afternoon highs
across the valley reaching the 103-106*F range. High pressure
begins to build rapidly over the area by Friday and again
Saturday. We will see an appreciable increase in overnight lows as
well. Overnight lows on Saturday in rural areas will stay warm,
around 70*F, with lows in urban areas around 75*F. Stout ridging
over Central California on Saturday and Sunday continues, leading
to very hot high temperatures in the 105-108*F range in the San
Joaquin Valley. From a probabilistic perspective, NBM
probabilities for afternoon highs reaching or exceeding 105*F in
the SJ Valley are quite high Saturday, ranging from 60-80%
depending on location. Ensemble guidance is currently suggesting
the heat impacts could extend beyond the 4th of July. Details on
the longevity of the heat wave will become more clear through the
week.
Given the mild Spring the San Joaquin Valley has experienced,
this significant heat wave may lead to higher impacts than a
heatwave of this magnitude would normally produce. Afternoon
highs jumping 20 degrees by this Saturday compared to today's
highs coupled with warm overnight lows will increase the risk of
heat-related illnesses significantly, especially to those
susceptible to heat illness such as the elderly or young children.
To combat the impacts of the heat, wearing light, loose-fitting
clothing along with limiting time outdoors can help. Maintaining
hydration and having access to an air conditioned building is
imperative to stay safe from heat related illness this 4th of July
weekend.
&&
.AVIATION...
VFR conditions will persist across Central California through at
least the next 24 hours.
&&
.AIR QUALITY ISSUES...
ISSUED: 06/25/2023 14:47
EXPIRES: 06/26/2023 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 high.
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...
None.
Source: NWS
