High pressure was in place over the region from the 11th through the 14th, creating a warming trend with inland temperatures 5 to 15 degrees above normal for that time of year. Temperatures in the lower deserts ranged from 97 up to 105 during these few days.
Every event with a place to put it; 1 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.
High pressure was in place over the region from the 11th through the 14th, creating a warming trend with inland temperatures 5 to 15 degrees above normal for that time of year. Temperatures in the lower deserts ranged from 97 up to 105 during these few days. A heat-related death was reported and confirmed due to this event.
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 May 12, 7:11 AM PST, 4 hours 49 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 811 AM PDT SAT MAY 12 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING MARINE LAYER CLOUDS INTO THE WESTERN VALLEYS DURING THE NIGHTS AND MORNINGS AND A SLOW WARMING TREND INLAND THROUGH THE MIDDLE OF NEXT WEEK. A TROUGH MOVING INLAND THROUGH CENTRAL CALIFORNIA LATE THURSDAY THROUGH FRIDAY WILL BRING GUSTY WINDS TO THE MOUNTAINS AND DESERTS ALONG WITH COOLING INLAND. THE TROUGH WILL ALSO PRODUCE A DEEPER MARINE LAYER...WITH NIGHT AND MORNING CLOUDS MOVING INTO THE FAR INLAND VALLEYS. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... MARINE LAYER STRATUS IS EXTENDING INTO THE WESTERN VALLEYS THIS MORNING ACCORDING TO VISIBLE SATELLITE IMAGERY. THE 12Z MIRAMAR SOUNDING INDICATES AN 8 DEGREE INVERSION AT ABOUT 2000 FEET. WITH NOT TOO STRONG OF AN INVERSION...STRATUS SHOULD CLEAR TO THE BEACHES BY LATE MORNING/EARLY AFTERNOON...ALTHOUGH IT MAY LINGER AT THE BEACHES THROUGH THE DAY. ONSHORE PRESSURE GRADIENTS ARE TRENDING WEAKER...AS THE GRADIENT FROM SAN DIEGO TO LAS VEGAS IS +4.7 MB WHERE AT THIS TIME YESTERDAY IT WAS +8.5 MB. THUS...WITH COOL ONSHORE FLOW WEAKENING...GOOD CLEARING OF STRATUS...AND HIGH PRESSURE MOVING IN ALOFT...DAY-TIME TEMPERATURES SHOULD INCREASE BY SEVERAL DEGREES TODAY FOR INLAND AREAS. THE AFOREMENTIONED HIGH PRESSURE MOVING IN ALOFT WILL ALSO SERVE TO PRODUCE A SLIGHTLY SHALLOWER MARINE LAYER THROUGH THURSDAY MORNING...ALTHOUGH NIGHT AND MORNING STRATUS WILL STILL MAKE IT INTO THE WESTERN VALLEYS. THE UPPER RIDGE WILL ALSO CONTINUE TO BRING WARMING INLAND THROUGH THE MIDDLE OF NEXT WEEK. GFS...ECMWF AND GEM ALL AGREE ON AN UPPER TROUGH MOVING OVER CENTRAL CALIFORNIA LATE THURSDAY THROUGH FRIDAY. THIS TROUGH WILL BRING COOLING INLAND...GUSTY WINDS OVER THE MOUNTAINS AND DESERTS...AND ALSO DEEPEN THE MARINE LAYER...WITH NIGHT AND MORNING STRATUS MOVING DEEP INTO THE INLAND VALLEYS. UPPER RIDGING BUILDING IN DURING THE WEEKEND SHOULD BRING SOME WARMING AND A SHALLOWER MARINE LAYER. && .AVIATION... 121530Z...LOW CLOUDS AROUND 1500 FEET ASL AND LOCAL INLAND VIS 3-5SM WILL SCATTER OUT THIS MORNING AROUND 17Z. LOW CLOUDS WILL RETURN TO COASTAL AIRPORTS AROUND 01-04Z AND WILL NOT COVER KONT FOR MUCH TIME IF IT REACHES THERE AT ALL. SCATTER OUT SUNDAY WILL BE SIMILAR TIMING...AROUND 16-17Z. OTHERWISE MOSTLY CLEAR AND VFR CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && PUBLIC...HARRISON AVIATION/MARINE...MM
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN DIEGO CA 400 PM PDT FRI MAY 11 2012 CAZ061-121300- COACHELLA VALLEY- 400 PM PDT FRI MAY 11 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME SOUTHWESTERN CALIFORNIA. .DAY ONE...TONIGHT GUSTY WESTERLY WINDS ARE EXPECTED THIS EVENING THROUGH BANNING PASS...AND ALONG AND NORTHEAST OF I-10 IN THE COACHELLA VALLEY. WIND GUSTS OF 45 MPH OR MORE AT TIMES MAY CAUSE DIFFICULT TRAVEL CONDITIONS FOR HIGH PROFILE VEHICLES. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. MAXWELL
The national radar mosaic for the moment the first event began.
1 heat. Local standard time, as filed.
An 86 year old male was hospitalized for a heat-related illness on May 12th near Mecca in the Salton Sea desert area of the Coachella Valley. The Riverside County Health Department confirmed his death on May 18 as heat-related. No mental issues were noted.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Heat, Coachella Valley | 2012-05-18 | 86 | Male | Unknown | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2012Every state in 2012This day in weather historyWarnings in California, May 2012
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: 385546.