A trough of upper-level low pressure dropped south into southern California with two disturbances rotating around it and plentiful moisture able to set of scattered showers and thunderstorms over the mountains and deserts. Thunderstorms over the San Diego County mountains drifted over the adjacent deserts and caused flash flooding along and north of Highway 78, south of Borrego Springs.
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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.
A trough of upper-level low pressure dropped south into southern California with two disturbances rotating around it and plentiful moisture able to set of scattered showers and thunderstorms over the mountains and deserts. Thunderstorms over the San Diego County mountains drifted over the adjacent deserts and caused flash flooding along and north of Highway 78, south of Borrego Springs.
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 22, 12:45 PM PST, 45 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 145 PM PDT THU MAY 22 2014 .SYNOPSIS... SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS THE MOUNTAINS AND DESERTS THROUGH THIS EVENING...WITH ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE WEST OF THE MOUNTAINS. ALTHOUGH DRIER CONDITIONS WILL DEVELOP ON FRIDAY...AS THE TROUGH MOVES EAST...SOME LINGERING INSTABILITY AND MOISTURE WILL CONTINUE THE THREAT OF SHOWERS OVER THE MOUNTAINS AND DESERTS. DRY AND WARMER CONDITIONS WILL THEN DEVELOP FOR THE HOLIDAY WEEKEND...WITH SOME COASTAL LOW CLOUDS AND FOG POSSIBLE EACH NIGHT. A GRADUAL COOLING TREND WILL THEN DEVELOP FOR THE MIDDLE AND LATTER PART OF THE WORK WEEK. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA THIS AFTERNOON. AS A RESULT...SCATTERED SHOWERS AND THUNDERSTORMS ARE DEVELOPING OVER THE MOUNTAINS AND DESERTS. CURRENTLY...AN URBAN AND SMALL STREAM FLOOD ADVISORY IS IN EFFECT FOR A PORTION OF THE SAN DIEGO COUNTY DESERTS...EAST OF SHELTER VALLEY. MEANWHILE...A THICK BLANKET OF LOW CLOUDS LINGERS WEST OF THE MOUNTAINS. ALTHOUGH THERE ARE A FEW BREAKS IN THE CLOUDS...MAINLY OVER THE INLAND EMPIRE...THERE ARE NOW ENOUGH HIGH CLOUDS LIMITING THE SURFACE HEATING. THE HRRR AND LOCAL WRF ARE STILL INDICATING THAT THE ELSINORE CONVERGENCE ZONE WILL GENERATE SOME ACTIVITY LATE THIS AFTERNOON AND DURING THE EARLY EVENING HOURS...SO HAVE KEPT A MENTION OF SHOWERS AND THUNDERSTORMS IN THE FORECAST FOR THE INLAND VALLEYS. HOWEVER...CONFIDENCE IS LOW GIVEN THE CURRENT SATELLITE TRENDS. THIS UPPER LEVEL TROUGH WILL SLOWLY SHIFT EAST TONIGHT AND DURING THE DAY ON FRIDAY. AS A RESULT...MOST AREAS WILL SEE DRIER AND WARMER CONDITIONS DEVELOP. HOWEVER...THERE WILL BE ENOUGH LINGERING INSTABILITY AND MOISTURE OVER THE MOUNTAINS AND DESERTS...THAT ISOLATED SHOWERS AND THUNDERSTORMS COULD DEVELOP ONCE AGAIN. HIGH PRESSURE THEN BUILD BACK ACROSS SOUTHERN CALIFORNIA FOR THE MEMORIAL DAY WEEKEND...WITH EVEN WARMER AND DRIER CONDITIONS DEVELOPING. A SHALLOW MARINE LAYER WILL REMAIN ALONG THE COAST THOUGH...WITH NIGHT AND MORNING LOW CLOUDS AND FOG POSSIBLE. ANOTHER TROUGH WILL THEN DIG ALONG THE WEST COAST BY THE MIDDLE PART OF THE WORK WEEK...WITH COOLER CONDITIONS AND A MORE EXTENSIVE MARINE LAYER DEVELOPING ONCE AGAIN. && .AVIATION... 222000Z...COAST/VALLEYS...AREAS OF LOW CLOUDS WITH BKN-OVC CIGS 2500-4000 FT MSL LAYERED TO 15000 FT. HIGHER TERRAIN WILL BE OBSCURED WITH AREAS OF FOG REDUCING VIS TO 3-5SM WHERE CLOUDS AND TERRAIN INTERSECT. LOW CLOUDS BECOME WIDESPREAD AGAIN AFTER 03Z FRI WITH OVC BASES 2000-3000 FT MSL AND TOPS NEAR 6000 FT MSL...OBSCURING HIGHER TERRAIN. PARTIAL CLEARING TO THE COAST AFT 18Z FRI. MTNS/DESERTS...ISOLATED-SCT SHOWERS AND TSTMS THROUGH 05Z FRI. && .MARINE... 200 PM...ISOLATED SHOWERS POSSIBLE OVER THE COASTAL WATERS THIS AFTERNOON. NO HAZARDOUS MARINE WEATHER IS EXPECTED FRIDAY THROUGH SUNDAY. && .FIRE WEATHER... SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS THE MOUNTAINS AND DESERTS THROUGH THIS EVENING...WITH ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE WEST OF THE MOUNTAINS...AS A COLD TROUGH OF LOW PRESSURE REMAINS OVER SOUTHERN CALIFORNIA. BRIEF AND LOCALLY HEAVY RAIN WILL CONTINUE TO BE POSSIBLE...WITH THESE THUNDERSTORMS. ALTHOUGH WETTING RAINS MAY OCCUR...THERE IS STILL THE POSSIBILITY OF LIGHTNING STRIKES STARTING FIRES OUTSIDE OF THE SHOWERS. A FEW SHOWERS MAY DEVELOP OVER THE MOUNTAINS AND DESERTS AGAIN ON FRIDAY AFTERNOON. DRY AND WARMER CONDITIONS WILL DEVELOP FOR THIS HOLIDAY WEEKEND. && .SKWYARN... SKYWARN ACTIVATION IS REQUESTED FOR SAN BERNARDINO...RIVERSIDE...AND SAN DIEGO COUNTIES. && .SGX WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC/FIRE WEATHER...PALMER AVIATION/MARINE...PG
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
218 PM PDT THU MAY 22 2014
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0209 PM FLASH FLOOD 7 SSW BORREGO SPRINGS 33.14N 116.38W
05/22/2014 SAN DIEGO CA LAW ENFORCEMENT
HIGHWAY PATROL IS REPORTING A FLASH FLOOD
ALONG SR78 AT YAQUI PASS. SEVERAL BOULDERS
ARE IN THE ROAD WAY, AND A SIGALERT HAS BEEN
ISSUED.
&&
NWS SAN DIEGO CA
IRIS SYSTEMThe San Diego radar (KNKX), 64 km away, was scanning. The volume nearest the first event began at 21:31 UTC.
1 flash flood, 1 debris flow. Local standard time, as filed.
California Highway Patrol reported flash flooding along Highway 78 at Yaqui Pass with several boulders in the roadway. A road alert was issued and the road closed for a time.
CHP reported a mudslide over Borrego Springs Road at San Pablo Road, with equipment needed to scrape the roadway. Rocks, sand, and standing water also extended to near Tilting T Drive and Christmas Circle. Flash flooding was also reported in Borrego Springs with 6 inches of flowing water, and one home with water entering it.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2014Every state in 2014This day in weather historyWarnings in California, May 2014
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: 522658, 522659.