High pressure building over the Desert Southwest brought a heat wave to the Bay Area in mid August. Multiple daily high temperature records were broken across the region.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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.
The episode as NWS MTR wrote it up.
High pressure building over the Desert Southwest brought a heat wave to the Bay Area in mid August. Multiple daily high temperature records were broken across the region. Heat prompted the delay of the school year for some students. Additionally, the heat caused a large power outage in the East Bay leaving thousands of residents without power.
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 San Francisco Bay Area, CA wrote its last area forecast discussion before the first event at Aug 14, 4:09 AM PST, 2 hours 51 minutes earlier.
Area Forecast Discussion
National Weather Service San Francisco Bay Area
509 AM PDT Wed Aug 14 2019
.SYNOPSIS...Hot daytime temperatures are expected across the
interior today into Thursday as high pressure builds over the
region. While coastal areas will also see a warming trend, onshore
flow will keep conditions cooler compared to inland areas. A
region-wide cooling trend is forecast for Friday and into the
upcoming weekend before warming once again early next week.
&&
.DISCUSSION...as of 03:35 AM PDT Wednesday...Temperatures early
this morning are generally in the upper 50s near the coast to
upper 60s in the warmer interior valleys under clear sky
conditions. Low clouds and fog generally remain well off shore and
along the Big Sur coastline. However, cannot rule out development
of low clouds and patchy fog along the coast through sunrise,
albeit likely to be less widespread compared to previous mornings.
The mid/upper level ridge of high pressure now centered over
Arizona and New Mexico will continue to build westward across
California through Thursday. This will result in 850 MB
temperatures warming to 24-26 deg C with daytime surface
temperatures ranging from 95 to 105 deg F across the interior.
While a few of the region's hottest locations may exceed 105 both
today and again on Thursday afternoon, coastal conditions will be
cooler due to persistent onshore flow. However, the warm air mass
aloft and compressed marine layer will allow for coastal locations
and adjacent areas to warm into the 70s to middle 80s. Given
this, a Heat Advisory is in effect for all interior locations of
the San Francisco Bay Area and Central Coast beginning at 11 AM
this morning and continuing through 8 PM Thursday evening. While
overnight cooling will provide some relief from the heat in many
interior valley locations, temperatures will only cool into the
70s in elevations above 1,000 feet.
Periods of overnight and morning low clouds and/or patchy fog
cannot be ruled out near the coast through midweek as well given
the lack of offshore winds. Again, the onshore flow and presence
of at least a shallow marine layer will be what keeps Heat Impact
Levels generally low near the coast as well. Region-wide cooling
is then forecast by Friday and into the upcoming weekend as the
ridge aloft breaks down in advance of an approaching mid/upper
level trough. Overall, look for a deepening marine layer as well
with temperatures back down to near or slightly below seasonal
averages for the upcoming weekend.
Another warming trend is then forecast for next week as high
pressure builds back over the region. However, forecast guidance
and ensembles do not indicate temperatures to be as warm as what
are expected for today and Thursday. Ongoing dry weather
conditions will also prevail through the forecast period.
&&
.AVIATION...as of 4:57 AM PDT Wednesday...For 12z TAFs. Clear
skies and light winds will prevail across area terminals thru the
morning hours. Patchy low clouds will likely develop over KMRY and
KSNS bringing diminished vsbys temporarily to the area this
morning. Onshore winds will increase to around 10 to 15 kt this
afternoon.
Vicinity of KSFO...VFR. Light winds will persist thru the morning
then increase to around 15 to 20 kt in the afternoon.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR. Patchy VLIFR-LIFR cigs will likely
develop over KMRY and KSNS bringing diminished vsbys temporarily
to the area this morning. Onshore winds will increase to around
10 to 15 kt this afternoon.
&&
.MARINE...as of 2:48 AM PDT Wednesday...High pressure building
over the Eastern Pacific will maintain moderate northwesterly
winds over the northern waters through the end of the week. Winds
will remain generally light elsewhere. This building high pressure
will generate moderate northwest wind waves at a period of around
7 seconds. Additionally, a smaller longer period westerly swell
will arrive Thursday and continue through the weekend. A
persistent light southerly swell will also persist.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...Heat Advisory...CAZ506-507-510>513-516>518
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pt Arena to Pt Reyes 0-10 nm from 3 PM
&&
PUBLIC FORECAST: RGass
AVIATION/MARINE: CW
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www.youtube.com/nwsbayareaThe national radar mosaic for the moment the first event began.
2 heat. Local standard time, as filed.
The start of the school year for some in Pittsburg was delayed due to the heat https://sanfrancisco.cbslocal.com/2019/08/15/heat-wave-liberty-high-brentwood-early-practice-pittsburg-highlands-elementary-postponed/.
Heat caused multiple power outages across portions of the East Bay leaving thousands of residents without power https://www.kron4.com/news/bay-area/extreme-heat-causes-major-power-outage-in-danville/.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2019Every state in 2019This day in weather historyWarnings in California, August 2019
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 841940, 841937.