Strong thunderstorms moved across the Antelope Valley, bringing heavy rain, flash flooding and wind damage to sections of the community of Palmdale.
Every event with a place to put it. 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 LOX wrote it up.
Strong thunderstorms moved across the Antelope Valley, bringing heavy rain, flash flooding and wind damage to sections of the community of Palmdale.
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 Los Angeles, CA wrote its last area forecast discussion before the first event at Jul 15, 3:45 PM PST, 1 hour 3 minutes earlier.
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 445 PM PDT THU JUL 15 2010 NEW AVIATION DISCUSSION .SYNOPSIS... STRONG HIGH PRESSURE OVER SOUTHERN CALIFORNIA IS THE MAIN FEATURE INTO SATURDAY FOR CONTINUED HOT TEMPERATURES. A SOUTHEAST FLOW ALOFT IS BRINGING MOISTURE INTO THE SOUTHLAND FOR A CHANCE OF SOME THUNDERSTORMS THROUGH FRIDAY...MAINLY OVER THE MOUNTAINS AND ANTELOPE VALLEY DURING THE AFTERNOON. && .SHORT TERM (TODAY-SUN)...SO FAR CONVECTION IN OUR FORECAST AREA HAS BEEN LIMITED TO JUST SOME MODERATE CU OVER THE MTNS. HOWEVER, MOISTURE CONTINUES TO INCREASE FROM THE SOUTH, AND GIVEN THE AMOUNT OF ACTIVITY ACROSS THE MTNS TO OUR SOUTH AND STILL PLENTY OF AFTERNOON HEATING THERE IS STILL A REASONABLE CHANCE FOR THUNDERSTORMS TODAY. SO THE FLASH FLOOD WATCH WILL REMAIN IN EFFECT UNTIL 6 PM FOR THE MTNS AND AV. OTHERWISE, ANOTHER HOT DAY ACROSS THE AREA. HIGHER DEWPOINTS MEAN HIGHER HUMIDITIES AND HIGHER DISCOMFORT LEVELS. DON'T SEE MUCH CHANGE IN THIS PATTERN THROUGH AT LEAST FRIDAY AND LIKELY SATURDAY AS WELL. CURRENT EXCESSIVE HEAT WARNING FOR PORTIONS OF THE VALLEYS AND MTNS GOES THROUGH FRIDAY AND THE WATCH FOR SATURDAY WILL LIKELY NEED TO BE CONVERTED TO A WARNING. ONE INTERESTING FEATURE TO KEEP AN EYE ON IS THE POTENTIAL FOR NOCTURNAL CONVECTION TONIGHT. 12Z NAM, AND TO A LESSER DEGREE THE 18Z NAM AND 12Z GFS, INDICATED A SHORT WAVE ROTATING THROUGH THE COAST AND VALLEYS SOUTH OF PT CONCEPTION BETWEEN 03Z AND 12Z TONIGHT. ALTHOUGH MODEL STABILITY PARAMETERS AREN'T AT ALL IMPRESSIVE, I CAN'T RULE OUT SOME SHOWERS OR THUNDERSTORMS DEVELOPING WEST OF THE MTNS TONIGHT. FOR NOW HAVE DECIDED THAT THE CHANCES FOR THIS HAPPENING, ESPECIALLY GIVEN THE WEAKER 18Z NAM, ARE NOT HIGH ENOUGH TO WARRANT A MENTION OF PRECIP IN THE ZONES. HOWEVER, THE STRONG STORM THAT DEVELOPED THIS AFTERNOON NEAR THE US/MEXICAN BORDER, OR ANY OTHER STORMS THAT DEVELOP TO OUR SOUTHEAST, COULD SEND OUT OUTFLOW BOUNDARIES DURING THE OVERNIGHT HOURS THAT WOULD INCREASE CHANCES FOR CONVECTION IN OUR AREA TONIGHT. NOT TOO MUCH CHANGE IN THE CONVECTIVE PARAMETERS FOR FRIDAY AFTERNOON SO AGAIN WENT WITH A CHANCE OF THUNDERSTORMS FOR THE MTNS AND ANTELOPE VALLEY. AND DEPENDING ON HOW WELL THINGS DEVELOP TODAY A FLASH FLOOD WATCH MAY OR MAY NOT BE NEEDED TOMORROW. MOISTURE AND STABILITY PARAMETERS NOT QUITE AS GOOD SATURDAY AND ESPECIALLY SUNDAY SO LEFT CONVECTION OUT FOR THOSE PERIODS. SOME COOLING IS EXPECTED SUNDAY, ESPECIALLY FOR COASTAL AREAS AS GRADIENTS START TRENDING STRONGER ONSHORE AND HIGH PRESSURE ALOFT STARTS TO WEAKEN. .LONG TERM (MON-THU)...TEMPS WILL RAPIDLY BE FALLING BACK TO NORMAL LEVELS NEXT WEEK AS A TROF RETURNS TO THE WEST COAST. TEMPS SHOULD REACH NORMAL BY TUESDAY, WITH LITTLE CHANGE THE REST OF THE WEEK. LOOK FOR A TYPICAL NIGHT AND MORNING MARINE LYR PATTERN NEXT WEEK. && .AVIATION... 15/2345Z LITTLE CHANCE OF LESS THAN VFR CONDS ANYWHERE TODAY...EXCEPT FOR SOME LIFR CLOUDS AND VIS ACROSS WESTERN SBA COUNTY. SCT TSRA ACTIVITY WILL CONTINUE ACROSS THE MTNS AND DESERTS THROUGH 10Z. THERE IS ALSO A 20 PERCENT CHC OF A TSRA OVER THE L.A. AND VENTURA COASTS AND VLYS FROM 03Z-12Z. TSRA WILL CONTAIN HAIL AS WELL AS MDT TO SVR CLEAR ICING. CLOUDS FROM THE TSRA COULD FORM BKN LYRS OVER THE AREA FROM 080-150. KLAX...MODERATE CONFIDENCE IN TAF. A 20 PERCENT CHC OF TSRA FROM 03Z-12Z. A 40 PERCENT CHC OF BKN LYRS FROM 080-150 AFTER 06Z. KBUR...MODERATE CONFIDENCE IN TAF. A 20 PERCENT CHC OF TSRA FROM 03Z-12Z. A 40 PERCENT CHC OF BKN LYRS FROM 080-150 AFTER 06Z. && .LOX WATCHES/WARNINGS/ADVISORIES... EXCESSIVE HEAT WARNING (SEE LAXNPWLOX). EXCESSIVE HEAT WATCH (SEE LAXNPWLOX). FLOOD WATCH (SEE LAXFFALOX). SMALL CRAFT ADVISORY (SEE LAXMWWLOX). && PUBLIC...WOFFORD AVIATION...RORKE SYNOPSIS...HOFFER WWW.WEATHER.GOV/LOSANGELES
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 1126 AM PDT THU JUL 15 2010 CAZ034>041-044>046-051>054-059-087-088-547-548-161300- SAN LUIS OBISPO COUNTY CENTRAL COAST- SANTA BARBARA COUNTY CENTRAL COAST-SANTA YNEZ VALLEY- SAN LUIS OBISPO COUNTY INTERIOR VALLEYS-CUYAMA VALLEY- SANTA BARBARA COUNTY SOUTH COAST-VENTURA COUNTY COAST- LOS ANGELES COUNTY COAST INCLUDING DOWNTOWN LOS ANGELES- VENTURA COUNTY INTERIOR VALLEYS-VENTURA COUNTY COASTAL VALLEYS- SANTA MONICA MOUNTAINS RECREATIONAL AREA- SAN LUIS OBISPO COUNTY MOUNTAINS- SANTA BARBARA COUNTY MOUNTAINS-VENTURA COUNTY MOUNTAINS- LOS ANGELES COUNTY MOUNTAINS EXCLUDING THE SANTA MONICA RANGE- ANTELOPE VALLEY-CATALINA ISLAND-SANTA CLARITA VALLEY- LOS ANGELES COUNTY SAN FERNANDO VALLEY- LOS ANGELES COUNTY SAN GABRIEL VALLEY- 1126 AM PDT THU JUL 15 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWESTERN CALIFORNIA. .DAY ONE... TODAY STRONG HIGH PRESSURE OVER THE REGION WILL BRING HOT WEATHER TO THE AREA WITH HEAT INDEX VALUES EXCEEDING 100 DEGREES ACROSS INLAND PORTIONS OF SOUTHWEST CALIFORNIA. SOUTHEAST FLOW AROUND THE HIGH PRESSURE CIRCULATION WILL TRANSPORT AMPLE MOISTURE TO PRODUCE A CHANCE OF SHOWERS AND THUNDERSTORMS. SLOW MOVING THUNDERSTORMS WITH BRIEF HEAVY RAINFALL HAVE THE POTENTIAL TO PRODUCE FLASH FLOODING...DANGEROUS CLOUD-TO-GROUND LIGHTNING...AND GUSTY AND ERRATIC WINDS. * EXCESSIVE HEAT WARNING.....SEE WWUS76 KLOX - NPWLOX FOR DETAILS * * FLOOD WATCH................SEE WGUS66 KLOX - FFALOX FOR DETAILS * .DAYS TWO THROUGH SEVEN... FRIDAY THROUGH WEDNESDAY HOT WEATHER WILL CONTINUE ACROSS INLAND PORTIONS OF SOUTHWEST CALIFORNIA THROUGH SUNDAY. HEAT INDEX VALUES WILL EXCEED 100 DEGREES ACROSS PORTIONS OF THE MOUNTAINS AND VALLEYS OF VENTURA AND LOS ANGELES COUNTIES FRIDAY...AND POSSIBLY SATURDAY. MID-LEVEL MOISTURE MOVING OVER THE AREA COULD BRING ISOLATED SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS AND DESERT FRIDAY AFTERNOON AND EVENING. * EXCESSIVE HEAT WATCH.......SEE WWUS76 KLOX - NPWLOX FOR DETAILS * .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. SWEET
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
537 PM PDT THU JUL 15 2010
CAZ054-059-160130-
ANTELOPE VALLEY CA-LOS ANGELES COUNTY MOUNTAINS EXCLUDING THE SANTA
MONICA RANGE CA-
537 PM PDT THU JUL 15 2010
...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN LOS ANGELES COUNTY UNTIL
630 PM PDT...
AT 530 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 5 MILES SOUTH OF PALMDALE...OR 9 MILES NORTHEAST
OF ACTON...MOVING NORTHWEST AT 5 MPH. MAJOR HIGHWAYS THAT COULD BE
IMPACTED INCLUDE HIGHWAYS 14 AND 138.
HAIL UP TO THE SIZE OF PENNIES IS EXPECTED WITH THIS STORM...ALONG
WITH HEAVY RAIN AND FREQUENT DANGEROUS LIGHTNING.
* LOCATIONS IMPACTED INCLUDE...
PALMDALE...
IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.
LAT...LON 3464 11834 3477 11808 3469 11792 3452 11792
3446 11802
TIME...MOT...LOC 0034Z 140DEG 4KT 3454 11807
GOMBERGThe national radar mosaic for the moment the first event began.
2 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Heavy rain, associated with a strong thunderstorm, produced flash flooding in the community of Palmdale. The flooding was reported along Avenue R.
Strong thunderstorm winds produced significant damage in the community of Palmdale. Trained weather spotters reported several large trees blown down as well as some fences.
Strong thunderstorm winds produced significant damage in the community of Palmdale. Along Palmdale Boulevard near 30th Street East, 30 utility poles were snapped off 2 to 5 feet above the ground by the strong gusts.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2010Every state in 2010This day in weather historyWarnings in California, July 2010
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: 241183, 241184, 241185.