Excessive Heat and Heat in California, August 29 to 30, 2021

Name: Excessive Heat and Heat in California, August 29 to 30, 2021
Start: 2021-08-29T10:00
End: 2021-08-30T19:00
Location: California

August 29 to 30, 2021 · NWS HNX · 13 events in 13 counties and zones

A large area of high pressure over the southwestern US strengthened over central California on August 28 and brought widespread dangerous heat to the area on August 29 and 30. High temperatures exceeded 110 degrees F across much of the Kern County Deserts on August 29 and 30 and exceeded 105 degrees F across much of the San Joaquin Valley and West Side Hills.

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 13

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS HNX wrote it up.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Hanford, CA wrote its last area forecast discussion before the first event at Aug 29, 8:38 AM PST, 1 hour 22 minutes earlier.

Area forecast discussion, Aug 29, 8:38 AM PST, 1 hour 22 minutes before

Area Forecast Discussion
National Weather Service Hanford CA
938 AM PDT Sun Aug 29 2021

.SYNOPSIS...
Hot conditions today and tomorrow before a cooldown. Dry weather
is forecast for the next 7 days.

&&

.DISCUSSION...
Heat and smoke will continue to be the main issue today and
tomorrow for most of the area as high pressure remains. However,
that ridge will lose its grip on the West Coast over the next 48
hours allowing for a trough to dig across the Western States.
Ensemble guidance is in good agreement in the development of this
scenario.

The main influence it will have on the interior of Central
California is a cooldown starting Tuesday, though expect to see
a couple days of cooling. By weeks end temps in the San Joaquin
Valley will drop a few degrees below seasonable norms.

The trough that will bring the cooldown will also kick up winds
across the usual areas, like the Kern Desert and the West Side of
the San Joaquin Valley, especially on Tuesday afternoon and
evening.

The is one wildcard in the forecast, the remnants of NORA, which
is current edging into western Mexico. While the bulk of the
moisture and energy will push north and east into Mexico and
Arizona early this week, there is potential for some monsoonal
surge to make its way into SoCal.

Currently, not expecting much will make its way into Central
California. However, with the southwest flow enhancement from the
trough midweek there could be a shower or two, though would expect
too much out of them.

&&

.AVIATION...
In the Sierra Nevada, areas of MVFR conditions with local
mountain obscured IFR visibilities are expected in smoke and haze.
In the San Joaquin Valley, areas of MVFR visibilities are
possible due to haze and patchy smoke.

&&

.AIR QUALITY ISSUES...
Please see SFOAQAHNX for an Air Quality Alert

On Sunday August 29 2021... Unhealthy in Tulare County. Unhealthy
for sensitive groups in Fresno... Kern... Kings... Madera and
Merced Counties and Sequoia National Park and Forest.
Further information is available at Valleyair.org

&&

.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
an/or to provide feedback.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM PDT this evening for CAZ179>191.

Excessive Heat Warning until 8 PM PDT Monday for CAZ198-199.

&&