An uppper level high centered over western Arizona ushered in hot weather to parts of Southern California. The deserts and inland valleys experienced much warmer than normal temperatures, with August 14th and 15th being the hottest days of the event.
Every event with a place to put it; 6 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 SGX wrote it up.
An uppper level high centered over western Arizona ushered in hot weather to parts of Southern California. The deserts and inland valleys experienced much warmer than normal temperatures, with August 14th and 15th being the hottest days of the event. Temperatures were hottest in the Coachella Valley, where Thermal reached 120 degrees and Palm Springs reached 119 on August 15th. Ramona reached 100 degrees and Lake Elsinore reached 105 degrees on August 14th.
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 Diego, CA wrote its last area forecast discussion before the first event at Aug 14, 8:20 AM PST, 40 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
920 AM PDT Wed Aug 14 2019
.SYNOPSIS...
It'll be hot in the inland valleys and deserts today and Thursday
with highs around 115 in the lower deserts, and from 100 to
105 in the upper deserts and the Inland Empire. This will be
followed by a cooling trend with high temperatures returning to
their seasonal norms over the weekend. Next week another round of
hot weather returns as high pressure aloft rebuilds over the
southwest. Night and morning low clouds and fog will extend a little
farther into the valleys this weekend as the marine layer deepens.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
The forecast challenge today is determining just how hot it will
get during this mini heatwave. 9 AM valley and desert temperatures
were running 2-6 degrees higher than at 9 AM Tuesday, and are on
pace to exceed yesterdays highs by a few degrees.
The 850 mb temperatures are forecast to be 1 degree C higher today
than yesterday, and then another degree higher on Thursday. Near
the surface the 2-meter temperatures follow that same trend. At
Riverside, the 2-meter temperature increases from 42.8C Tuesday to
46.2C today and then peak at 46.6C Thursday. Another factor
contributing to the heat will drier boundary layer conditions.
Surface dewpoints at Riverside fall from 48F Tuesday to 39F today
and to 37F Thursday. At Thermal they fall from 43F Tuesday, to 37F
today and to 30F Thursday. These factors all add confidence to the
forecast of hot weather in the valleys and deserts where Heat
Advisories and Heat Warnings are in effect through Thursday evening.
Closer to the coast, areas of dense fog impacted the coastal and
western valley zones this morning. Expect a similar scenario
Thursday morning with little change in the overall depth of the
marine layer. This cool marine layer will moderate temperatures
within 10 miles of the coast.
The heat pattern breaks down Friday as high pressure over the
southwest weakens and is briefly replaced by zonal flow and lower
heights Saturday and Sunday. High temperatures this weekend will be
closer to where they should be for mid August. The marine layer will
deepen slightly this weekend with low clouds reaching the western
valleys each night.
Outlook for Next Week: High pressure aloft rebuilds back over the
southwest for gradual warming Monday and Tuesday, peaking Wednesday
and Thursday when valley and deserts high temps may be similar to
what we are experiencing now. The marine layer will become shallower
with night and morning low clouds limited to coastal areas.
&&
.AVIATION...
141515Z...Coast/Valleys...Low clouds and fog still extend locally 10
miles inland at 8 am PDT. Cigs at coastal TAF sites are 500-800 ft
MSL with tops to 1100 ft MSL. Areas of vis 1-3 miles, locally 1/4-
1/2 mile in fog on elevated coastal terrain. Expect SCT clouds and
unrestricted vis at coastal TAF sites around 17Z. Patchy low clouds
with bases below 600 ft MSL and areas of fog with vis 1 mile or less
developing along the immediate coast after 06Z Thu, possibly
spreading a few miles inland by 15Z Thu. Low confidence in timing,
but moderate confidence in occurrence at the coastal airports
between 10Z and 15Z Thu.
Mountains/Deserts...Mostly clear with unrestricted vis through
Wed afternoon.
&&
.MARINE...
No hazardous marine weather is expected through Sunday.
&&
.SKYWARN...
Skywarn activation will not be needed this week.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory from 11 AM this morning to 9 PM PDT Thursday for
San Bernardino and Riverside County Valleys-The Inland
Empire-San Diego County Valleys.
Excessive Heat Warning from 11 AM this morning to 9 PM PDT
Thursday for Coachella Valley-San Diego County Deserts-San
Gorgonio Pass Near Banning.
PZ...NONE.
&&
PUBLIC...Moede
AVIATION/MARINE...PGThe national radar mosaic for the moment the first event began.
5 excessive heat, 1 wildfire. Local standard time, as filed.
Numerous locations in the Coachella Valley experienced extreme high temperatures on August 14th and 15th. Thermal Airport recorded a high temperature of 120 degrees, and Palm Springs Airport recorded a high temperature of 119 degrees on August 15th.
Many locations throughout the Inland Empire reported temperatures in excess of 100 degrees on August 14th and 15th. The warmest temperatures were recorded at Lake Elsinore and San Jacinto (105 on the 14th and 104 on the 14th).
Many locations in the San Diego County deserts recorded extreme temperatures August 14th-15th. Borrego Springs recorded a high temperature of 115 degrees, and Ocotillo Wells recorded a high temperature of 119 degrees on August 15th.
Many locations in the High Desert recorded high temperatures in excess of 100 degrees on August 14th and 15th. Hesperia reached a high of 103 degrees and Apple Valley reached a high of 104 degrees on August 15th.
Many locations in the San Diego County valleys experienced extreme temperatures on August 14th and 15th. Valley Center recorded a high temperature of 101 degrees, and Ramona and Alpine recorded a high temperature of 99 on August 15th.
A 5 acre vegetation fire broke out at Bay Ave. and Phyllis Ave. in Moreno Valley late on August 15th. 2 single family homes were destroyed, as well as 3 outbuildings and 9 vehicles.
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: 849936, 849937, 849940, 850026, 849941, 850022.