A strong surge of moisture associated with Hurricane Hillary pushed northward into central California on August 19. This moisture surge resulted in the development of showers and thunderstorms mainly the San Joaquin Valley during the afternoon and evening hours with the most noticeable impact being outflow wind gusts.
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 HNX wrote it up.
A strong surge of moisture associated with Hurricane Hillary pushed northward into central California on August 19. This moisture surge resulted in the development of showers and thunderstorms mainly the San Joaquin Valley during the afternoon and evening hours with the most noticeable impact being outflow wind gusts. Hillary weakened into a Tropical Storm and moved into southern California on August 20 resulting in moderate to heavy rainfall across the mountains and deserts of Kern County with several stations picking up between 3 and 5 inches of rainfall with a few stations receiving more than 5.5 inches of rainfall. Much of the Sierra Nevada south of Kings Canyon picked up between 1 and 3 inches of rainfall while the south San Joaquin Valley measured between a half inch and an inch. Further north, rainfall amounts were lower, but many new daily rainfall records were set for August 20. Numerous reports of flash flooding and road closures were observed in Kern County during the afternoon of August 20 through the early morning of August 21. The rains dissipated during the morning of August 21, but an offshore trough provided for enough instability for thunderstorms to break out over the area during the afternoon of August 21 which produced locally heavy rainfall. The trough lifted northeast on August 22 resulting in the moisture being pushed out of our area and drier conditions prevailed for the remainder of the week.
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 Hanford, CA wrote its last area forecast discussion before the first event at Aug 19, 11:24 AM PST, 3 hours 45 minutes earlier.
Area Forecast Discussion National Weather Service Hanford CA 1224 PM PDT Sat Aug 19 2023 .SYNOPSIS... Strong thunderstorms across Central California are possible today associated with moisture ahead of Hurricane Hillary. More widespread precipitation is forecast for tomorrow, especially in Tulare and Kern County -- including the Mojave Desert -- where catastrophic flash flooding is conceivable. Rainfall associated with Hilary will mostly exit the region by late Monday. A few residual showers and thunderstorms in the Sierra Nevada are forecast through the end of the work week. && .DISCUSSION... All eyes are currently on Major Hurricane Hilary, which is still south of the forecast area, but impacts begin today. Moisture associated with TC Hilary coupled with hot surface temperatures will provide enough instability to support strong thunderstorms. A severe thunderstorm or two today cannot be ruled out, with the main hazard being strong downdraft winds. We have been included in a rare "Marginal" Risk by the Storm Prediction Center for just about the entire forecast area. The risk for severe weather will decrease when the sun goes down later this evening. However, the flood thread will continue to increase through the night. Additionally, breezy conditions through the Grapevine and Highway 58 at the south end of the valley today may lead to some blowing dust. Once the isolated thunderstorm risk wanes tonight, the broader rain shield will move over the area. This precipitation shield will grow in coverage through the night and morning hours tomorrow. There is a risk for heavy rain bands associated with Hilary that have catastrophic flash flooding potential due to the unusually potent moisture source that is associated with Hilary in the Mojave Desert. The Weather Prediction Center has put the desert area of Kern County in a very, very rare "High Risk" for excessive rainfall on Sunday. The high desert in Kern County will be really under the gun in terms of flash flooding potential later tomorrow morning through the evening hours as abundant moisture associated with Hilary pushes inland. Flooding potential extends both north and west of the desert tomorrow... flooding in locations such as Bakersfield and Kernville cannot be ruled out, as well as foothill and mountain locations in Tulare County. The main circulation associated with Hilary will exit the region later on Monday, which is when the heaviest rainfall and our Flood Watch are set to expire. Once things are all said and done, the wettest locations in the Mojave Desert in Kern County may see 4-5 inches of rain through Monday. Residual moisture will linger over the High Sierra through the rest of the week. This will lead to thunderstorm potential through the end of next week, but will be isolated in nature compared to the showers and storms associated with Hilary. && .AVIATION... Areas of MVFR and local mountain obscuring IFR conditions in and near showers and thunderstorms in the Sierra Nevada and adjacent foothills after Saturday 19z. Showers and thunderstorms will also impact the Kern County desert with areas of MVFR after Saturday 19Z. Otherwise, VFR conditions will prevail through at least the next 24 hours. && .AIR QUALITY ISSUES... ISSUED: 08/18/2023 14:47 EXPIRES: 08/19/2023 23:59 None. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information and/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Flood Watch through Monday evening for CAZ314-316-322-328>339. && ab weather.gov/hanford
Special Weather Statement
National Weather Service San Joaquin Valley CA
147 PM PDT Sat Aug 19 2023
CAZ308-192130-
West Side Mountains South of 198 CA-
147 PM PDT Sat Aug 19 2023
...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL KERN COUNTY THROUGH
230 PM PDT...
At 147 PM PDT, Doppler radar was tracking a strong thunderstorm 14
miles northwest of McKittrick moving northwest at 20 mph.
HAZARD...Wind gusts up to 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Twisselman.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3535 11981 3535 11988 3544 11988 3544 11999
3547 12000 3547 12001 3553 12007 3562 11991
3538 11973 3534 11980
TIME...MOT...LOC 2047Z 142DEG 16KT 3539 11986
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
abSpecial Weather Statement
National Weather Service San Joaquin Valley CA
247 PM PDT Sat Aug 19 2023
CAZ315-321-322-192215-
Southeast San Joaquin Valley CA-South End Sierra Foothills CA-
South End of the Lower Sierra CA-
247 PM PDT Sat Aug 19 2023
...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL KERN AND SOUTH
CENTRAL TULARE COUNTIES THROUGH 315 PM PDT...
At 246 PM PDT, Doppler radar was tracking a strong thunderstorm 24
miles southeast of Porterville, moving northwest at 15 mph.
HAZARD...Wind gusts up to 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Richgrove and Fountain Springs.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3576 11867 3566 11880 3580 11911 3599 11887
TIME...MOT...LOC 2146Z 134DEG 13KT 3575 11881
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
abSpecial Weather Statement
National Weather Service San Joaquin Valley CA
301 PM PDT Sat Aug 19 2023
CAZ314>316-321-322-331>333-192230-
Southeast San Joaquin Valley CA-South End Sierra Foothills CA-
South End of the Lower Sierra CA-Bakersfield CA-
Piute Walker Basin CA-South End of the Upper Sierra CA-
Kern River Valley CA-South End San Joaquin Valley CA-
301 PM PDT Sat Aug 19 2023
...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL KERN AND SOUTHERN
TULARE COUNTIES THROUGH 330 PM PDT...
At 301 PM PDT, Doppler radar was tracking a strong thunderstorm 12
miles southwest of Bodfish, or 21 miles northeast of Bakersfield,
moving northwest at 35 mph.
HAZARD...Wind gusts up to 50 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Glennville and Democrat.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 3553 11849 3536 11870 3556 11906 3580 11871
TIME...MOT...LOC 2201Z 138DEG 29KT 3550 11868
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH
abSpecial Weather Statement
National Weather Service San Joaquin Valley CA
335 PM PDT Sat Aug 19 2023
CAZ310-314-315-321-322-332-192315-
Southeast San Joaquin Valley CA-South End Sierra Foothills CA-
South End of the Lower Sierra CA-Delano-Wasco-Shafter CA-
Bakersfield CA-Kern River Valley CA-
335 PM PDT Sat Aug 19 2023
...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL KERN COUNTY
THROUGH 415 PM PDT...
At 334 PM PDT, Doppler radar was tracking a strong thunderstorm 16
miles north of Bakersfield, moving northwest at 25 mph.
HAZARD...Wind gusts up to 50 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
This storm will remain over mainly rural areas of north central Kern
County.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 3547 11874 3543 11890 3577 11923 3577 11875
TIME...MOT...LOC 2234Z 140DEG 23KT 3558 11891
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH
DASSpecial Weather Statement
National Weather Service San Joaquin Valley CA
356 PM PDT Sat Aug 19 2023
CAZ316-333-334-192345-
Piute Walker Basin CA-South End San Joaquin Valley CA-Tehachapi CA-
356 PM PDT Sat Aug 19 2023
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL KERN COUNTY THROUGH 445
PM PDT...
At 356 PM PDT, Doppler radar was tracking a strong thunderstorm near
Golden Hills, or 29 miles east of Bakersfield, moving west at 15 mph.
HAZARD...Wind gusts up to 50 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Tehachapi, Golden Hills, Stallion Springs, Keene, and Bear Valley
Springs.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3524 11842 3512 11847 3513 11873 3532 11869
TIME...MOT...LOC 2256Z 100DEG 15KT 3520 11853
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH
DASSpecial Weather Statement
National Weather Service San Joaquin Valley CA
359 PM PDT Sat Aug 19 2023
CAZ334-338-192345-
Mojave Desert Slopes CA-Tehachapi CA-
359 PM PDT Sat Aug 19 2023
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL KERN COUNTY THROUGH 445
PM PDT...
At 359 PM PDT, Doppler radar was tracking a strong thunderstorm 7
miles east of Tehachapi, or 29 miles north of Lancaster, moving
northwest at 15 mph.
HAZARD...Wind gusts up to 50 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Tehachapi and Water Canyon.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3514 11823 3501 11827 3506 11850 3526 11840
TIME...MOT...LOC 2259Z 114DEG 15KT 3510 11835
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH
DASThe San Joaquin Valley radar (KHNX), 80 km away, was scanning. The volume nearest the first event began at 23:08 UTC.
26 flash flood, 11 thunderstorm wind, 10 flood, 1 funnel cloud, 1 debris flow, 1 strong wind. Local standard time, as filed.
California Highway Patrol reported multiple trees blocking the right lane of northbound SR 99 at Sherwood Ave. in McFarland.
Public report of 50 trees blown down at Belmont Country Club. A storm survey indicated that the damage was caused by straight line winds from a microburst.
California Highway Patrol reported standing water on SR 99 under the overpasses of Cecil Ave. and Garces Hwy. in Delano.
Fresno TV station showed a video of a funnel cloud in Northwest Fresno near the intersection of Shaw Ave. and Brawley Ave.
California Highway Patrol reported a very large downed tree on N. Fulton Ave. between the intersections of E. Bremer Ave. and E. Dennett Ave.
California Highway Patrol reported a downed tree blocking the roadway on N. Safford Ave. between E. Rialto Ave. and E. Santa Ana Ave.
California Highway Patrol reported a large tree branch on the roadway near the intersection of S. Armstrong Ave. and E. Butler Ave.
California Highway Patrol reported downed power lines in the roadway at the intersection of E. McKinley Ave. and N. DeWolf Ave.
California Highway Patrol reported a downed tree across the roadway on E. Cornell Ave near the intersection of N. Sierra Vista Ave.
California Highway Patrol reported a large tree branch in the roadway on E. White Ave. near the intersection of N. Villa Ave.
Flooding and debris on the Cameron overpass on SR 58 caused a closure in both directions as SR 58 became impassible.
California Highway Patrol reported a power pole and lines down at the intersection of E. Olive Ave. and N. Temperance Ave.
The PG&E station at Penon Blanco reported a measured wind gust of 62 mph with a thunderstorm.
California Highway Patrol reported a downed tree blocking the roadway on Old Toll Rd. near the intersection of Pendola Garden Rd.
California Highway Patrol reported Cameron Canyon Rd was closed between Tehachapi Willow Springs Rd. and SR 58 due to heavy debris covering the road.
California Highway Patrol reported flooding and debris in roadway completely covering the intersection of Oak Creek Rd. and CalPortland Access Rd.
California Highway Patrol reported heavy flooding on Redrock-Randsburg Rd. between US 395 and SR 14 which required the road to be closed.
California Highway Patrol reported a large rock blocking lanes on Interstate 5 south of Wheeler Ridge Rd.
California Highway Patrol reported large rocks in the roadway on Sand Canyon Rd. 3 miles north of Tehachapi Blvd. which required clearing with a plow.
California Highway Patrol reported a large rock on northbound Interstate 5 south south of Grapevine Rd. near the truck escape ramp.
California Highway Patrol reported a large rock on Interstate 5 south of Lebec.
California Highway Patrol reported several large rocks washed up on the Frazier Mountain Park onramp onto Interstate 5.
California Highway Patrol reported a large rock washed up on northbound Interstate 5 just south of the east escape ramp.
California Highway Patrol reported several large rocks as least 1 foot in diameter washed up on northbound Interstate 5 just south of Grapevine Rd..
Public report of roadway flooding at the intersection of Kratzmeyer Rd. and Nord Ave.
California Highway Patrol reported roadway flooding on Sand Canyon Rd. north of SR 58.
California Highway Patrol reported roadway flooding at northbound SR 99 and SR 166 just south of Mettler.
California Highway Patrol reported flooding causing erosion and running over the roadway at the intersection of Elm Trail and Mount Pinos Way in Frazier Park.
The Kern County Emergency Manager reported Oak Creek Blvd. was closed between Tehachapi Willow Springs Rd. and Koch St. due to flooding.
California Highway Patrol reported a tree blocking the northbound lane at the intersection of N. Lake Rd. and E. Cardella Rd.
The Kern County Emergency Manager reported the SR 58 was closed between Tehachapi Willow Springs Rd. and Sand Canyon Rd. due to heavy flooding.
The Kern County Emergency Manager reported Copus Rd. was closed between Old River Rd. and Basic School Rd. due to heavy flooding.
California Highway Patrol reported large rocks across the roadway at the intersection of SR 58 and SR 223. near Bealville.
California Highway Patrol reported roadway flooding on Garlock Rd. near SR 395.
California Highway Patrol reported large rocks on SR 178 southwest of Lake Isabella.
California Highway Patrol reported the intersection of SR 43 and Panama Lane was completely flooded.
California Highway Patrol reported the roadway was completely flooded at the intersection of Piute Mountain Rd. and Kelso Valley Rd.
California Highway Patrol reported the northbound lanes of SR 99 were completely flooded at the intersection of SR 99 and SR 166.
The Ridgecrest Fire Department reported heavy flooding in a portion of Ridgecrest that resulted in an evacuation for areas bounded by West Ridgecrest Blvd, North Alvord St. West Las Flores Ave. and North China Lake Blvd. Other portions of Ridgecrest were impacted by soil erosion and instability resulting in heavy runoff.
Kern County officials reported a closure of Tehachapi Blvd. east of Tehachapi Willow Springs Rd. due to heavy flooding.
Kern County officials reported a road closure of South Kelso Valley Rd. and Birch Springs Pass due to heavy flooding.
California Highway Patrol reported portions of southbound Interstate 5 from the Grapevine scales to Lebec were completely flooded.
California Highway Patrol reported a rock slide on southbound Interstate 5 just south of Fort Tejon Rd.
California Highway Patrol reported all lanes on SR 178 were blocked by heavy flooding entering the mouth of Kern Canyon.
Kern County officials reported a closure of Edison Hwy. from Bena Rd. to Towerline Rd. due to heavy flooding.
Caltrans reported a road closure of SR 14 between SR 58 and SR 178 due to flooding.
California Highway Patrol reported roadway flooding on Lebec Rd. from Frazier Mountain Park Rd. to Landfill Rd.
California Highway Patrol reported roadway flooding on southbound Interstate 5 between the scales and Grapevine Rd.
California Highway Patrol reported several stuck vehicles on Neuralia Rd. near Cantil Rd. with a road closure in place.
California Highway Patrol reported roadway flooding on Interstate 5 9S Los Banos north of the SR 165 exchange.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2023Every state in 2023This day in weather historyWarnings in California, August 2023
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: 1116658, 1116662, 1116666, 1116652, 1116653, 1116655, 1116667, 1116668, 1116670, 1116671, 1116673, 1116656, 1116679, 1116681, 1116683, 1116684, 1116685, 1116686, 1116687, 1116688, 1116689, 1116690, 1116691, 1116692, 1116693, 1116694, 1116699, 1116695, 1116696, 1116697, 1116698, 1116700, 1116701, 1116702, 1116703, 1116931, 1116932, 1116933, 1116939, 1116941, and more.