Strong Wind, Sw S.J. Valley
- When
- May 4, 4:00 PM PST to May 5, 1:00 AM PST
- Where
- Sw S.J. Valley forecast zone
- Measured
- 45 kt (52 mph) measured gust
- Property damage
- $5,000
- Reported by
- Mesonet
Tornado and Flood in California, May 4 to 9, 2013
May began warm and dry. Humidities were in the teens across the mountains of Kern and Tulare Counties on May 1st through the 3rd, and as highs in the southern San Joaquin Valley climbed into the mid 90s on the 2nd, relative humidities in the south end of the Valley fell to 10 percent or lower for several hours.
Where it happened
Every event with a place to put it. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- $5,000
- Crop damage
- None recorded
- Events
- 4
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.
What happened
The episode as NWS HNX wrote it up.
May began warm and dry. Humidities were in the teens across the mountains of Kern and Tulare Counties on May 1st through the 3rd, and as highs in the southern San Joaquin Valley climbed into the mid 90s on the 2nd, relative humidities in the south end of the Valley fell to 10 percent or lower for several hours.
An upper-level low approached central California on May 4th. The southerly flow ahead of the low funneled through the passes and canyons of the Temblors, Diablo Range and the Tehachapi Mountains. This created gusty winds along the west side of the San Joaquin Valley that persisted from the afternoon of the 4th through the evening of 5th. Winds gusted to 51 mph at Sunflower Valley, and to 50 mph at Panoche Road. A gust to 59 mph was measured at the California Highway Patrol Weigh Station at the base of the Grapevine during the late afternoon of May 5th.|Winds also gusted to 45 mph at Meadows Field, Bakersfield during this time. The gust at Meadows Field tied the highest gust on record at Bakersfield for May, last occurring on May 23rd, 1990.
The upper-level low moved to off Monterey Bay on the evening of May 5th. In addition to the gusty winds generated by the cyclonic circulation, the low also spun subtropical moisture into central California, and as a series of upper-level disturbances rotated around the low, they triggered showers and thunderstorms across the region on the 6th. One of the thunderstorms spawned a tornado that touched down at 7:10 PM on May 6th in the dry riverbed of the Kern River near the intersection of Old River Road and Stockdale Highway, not far from the California State University, Bakersfield, campus in west Bakersfield.
The low moved into San Luis Obispo County during the night of May 6th-7th, and tracked across Kern County during the morning of the 7th. Moderate showers continued across parts of the central California interior through the morning hours, and continued over the Southern Sierra Nevada into the afternoon. A few of the stronger showers caused some road flooding, including northeast of Chowchilla and northwest of Bakersfield.
As the low moved east of California on May 8th, the cyclonic flow continued to generate showers over the eastern flanks of the Southern Sierra Nevada, some of which drifted west of the crest and into the central and southern San Joaquin Valley. Showers also moved into the Tehachapi Mountains.
Thunderstorms over the Southern Sierra Nevada during the afternoon and evening of May 9th dropped small hail on the floor of Yosemite Valley. Nearly two inches of rain fell on Yosemite Valley, with 1.87 inch falling in only 30 minutes. This heavy rain caused some road flooding and ponding of water on the Yosemite Valley floor.
Further south, thunderstorms over southeastern Kern County produced little rain, but did generate gusty winds. One thunderstorm generated an outflow wind that was measured at 40 mph at the Edwards AFB North Base Auxiliary Field. Winds also gusted to 55 mph in the Indian Wells Valley.
What forecasters said that day
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 May 4, 2:00 PM PST, 2 hours earlier.
Area forecast discussion, May 4, 2:00 PM PST, 2 hours before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
300 PM PDT SAT MAY 4 2013
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL CONTINUE TO MOVE OVER NORTHERN
CALIFORNIA THROUGH THE REMAINDER OF THE WEEKEND BRINGING A SMALL
THREAT OF AFTERNOON AND EVENING THUNDERSTORMS TO THE SIERRA. ON
MONDAY AND TUESDAY...THIS LOW WILL REMAIN OVER THE REGION FOR AN
INCREASED THREAT OF SHOWERS AND THUNDERSTORMS SPREADING TO MUCH OF
CENTRAL CALIFORNIA.
&&
.DISCUSSION...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ONGOING ACROSS THE
SOUTHERN SIERRA. THERE HAVE BEEN A FEW CLOUD TO GROUND LIGHTNING
STRIKES. WESTERLY FLOW HAS TAKEN HOLD WITH ALL OF THE CONVECTION
BLOWING OFF DRAMATICALLY TO THE EAST INTO NEVADA. EXPECT THIS
ACTIVITY TO BE MAINLY DIURNALLY DRIVEN AS THE CUTOFF LOW MOVES TO
OFFSHORE NORTHERN CALIFORNIA LATER TONIGHT. OUR CONVECTION SHOULD
DIMINISH AFTER DARK THIS EVENING.
WITH A DRY FLOW ON SUNDAY WE DON/T EXPECT MUCH IN THE WAY OF
CONVECTION UNTIL LATE SUNDAY NIGHT WHEN THE CUTOFF LOW BEGINS TO
MOVE EAST INTO CENTRAL CALIFORNIA. THEN FROM LATE SUNDAY NIGHT
THROUGH TUESDAY WE HAVE INCREASED POPS TO BETWEEN 30-50 PERCENT
ACROSS MOST OF OUR COUNTY WARNING AREA. THE BEST CHANCES FOR
SHOWERS AND STORMS WILL BE MONDAY AFTERNOON AND EVENING AND MAYBE
AGAIN ON TUESDAY. WITH A SUBTROPICAL FLOW OF MOISTURE WE DON/T
BELIEVE THAT DRY THUNDERSTORMS WILL BE A MAJOR CONCERN.
INSTEAD...ANY OF THE HEAVIER STORMS COULD GENERATE SOME PONDING
WATER IN THE VALLEY AND SMALL FLOODS IN THE MOUNTAINS AND DESERTS.
SOME CONVECTION WILL BE POSSIBLE AGAIN ON WEDNESDAY AND WEDNESDAY
EVENING BUT RELEGATED MAINLY NEAR THE CREST. A STRONGER RIDGE OF
HIGH PRESSURE WILL BUILD IN TOWARDS THE END OF THE WORK
WEEK...SHUTTING OFF THE CONVECTION MACHINE AND BRINGING A TREND TO
ABOVE NORMAL TEMPERATURES ONCE AGAIN.
&&
.AVIATION...
VFR ACROSS THE CENTRAL CA INTERIOR EXCEPT ISOLD AFTERNOON AND
EVENING TSTMS IN THE SRN SIERRA.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS HIGH.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 05-04 100:2004 58:1930 64:2004 39:1950
KFAT 05-05 99:1990 57:1921 65:1989 36:1975
KFAT 05-06 100:1987 58:1921 69:1992 41:1975
KBFL 05-04 101:2004 59:1930 70:1982 39:1893
KBFL 05-05 100:1990 61:1932 69:1909 42:1930
KBFL 05-06 104:1987 55:1921 71:1989 42:1988
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
PUBLIC...BROTHERTON
AVN/FW...BINGHAM
SYNOPSIS...ANDERSEN
WEATHER.GOV/HANFORDHazardous weather outlook, May 4, 4:31 AM PST, 11 hours 29 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 531 AM PDT SAT MAY 4 2013 CAZ095-097-051245- KERN COUNTY MOUNTAINS-TULARE COUNTY MOUNTAINS- 531 AM PDT SAT MAY 4 2013 ...ISOLATED THUNDERSTORMS POSSIBLE BY EARLY NEXT WEEK... THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE TULARE AND KERN COUNTY MOUNTAINS. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER EXPECTED. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY ISOLATED THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOONS AND EVENINGS STARTING SUNDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION IS NOT ANTICIPATED. WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE. CAZ089>094-096-098-099-051245- WEST CENTRAL SAN JOAQUIN VALLEY-EAST CENTRAL SAN JOAQUIN VALLEY- SOUTHWESTERN SAN JOAQUIN VALLEY-SOUTHEASTERN SAN JOAQUIN VALLEY- MARIPOSA MADERA AND FRESNO COUNTY FOOTHILLS- TULARE COUNTY FOOTHILLS- SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON-INDIAN WELLS VALLEY- SOUTHEASTERN KERN COUNTY DESERT- 531 AM PDT SAT MAY 4 2013 ...THUNDERSTORMS POSSIBLE MONDAY AND TUESDAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE REMAINDER OF THE CENTRAL CALIFORNIA INTERIOR. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER EXPECTED. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY ISOLATED THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOONS AND EVENINGS ON MONDAY AND TUESDAY THROUGHOUT THE CENTRAL CALIFORNIA INTERIOR. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION IS NOT ANTICIPATED. WEATHER SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT OR UNUSUAL CONDITIONS TO THE NATIONAL WEATHER SERVICE. DUDLEY
In the hours before
Special weather statement, May 4, 1:50 PM PST, 2 hours 10 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 250 PM PDT SAT MAY 4 2013 CAZ089>099-050600- WEST CENTRAL SAN JOAQUIN VALLEY-EAST CENTRAL SAN JOAQUIN VALLEY- SOUTHWESTERN SAN JOAQUIN VALLEY-SOUTHEASTERN SAN JOAQUIN VALLEY- MARIPOSA MADERA AND FRESNO COUNTY FOOTHILLS- TULARE COUNTY FOOTHILLS-KERN COUNTY MOUNTAINS- SIERRA NEVADA FROM YOSEMITE TO KINGS CANYON- TULARE COUNTY MOUNTAINS-INDIAN WELLS VALLEY- SOUTHEASTERN KERN COUNTY DESERT- 250 PM PDT SAT MAY 4 2013 ...THUNDERSTORMS POSSIBLE THROUGH TUESDAY NIGHT... A LOW PRESSURE SYSTEM WILL MEANDER AROUND THE REGION THROUGH EARLY NEXT WEEK. SCATTERED THUNDERSTORMS WILL OCCUR THIS EVENING ACROSS THE SOUTHERN SIERRA. FROM SUNDAY NIGHT THROUGH TUESDAY NIGHT...SCATTERED THUNDERSTORMS WILL AGAIN BE POSSIBLE ACROSS MUCH OF CENTRAL CALIFORNIA. THE MAIN THREAT FROM THESE THUNDERSTORMS WILL BE DANGEROUS CLOUD TO GROUND LIGHTNING AND STRONG AND ERRATIC WIND GUSTS. BRIEF HEAVY RAIN WILL ALSO BE POSSIBLE WHICH COULD CAUSE PONDING WATER ON AREA ROADS. JMB WEATHER.GOV/HANFORD
The radar
The Los Angeles radar (KVTX), 108 km away, was scanning. The volume nearest the first event began at 02:12 UTC.
Event by event
1 strong wind, 1 tornado, 1 heavy rain, 1 flood. Local standard time, as filed.
Tornado, Kern
- When
- May 6, 6:10 PM PST to 6:12 PM PST
- Where
- Kern County, 1.39 mi E of Jastro to 1.44 mi SSE of Oil Jct
- Rating
- EF0
- Path length
- 0.44 mi
- Path width
- 15 yd
- Reported by
- Public
- Coordinates
- 35.377, -119.046
A tornado occurred on the west side of Bakersfield. It was weak and short lived. The location was near the intersection of Stockdale Hwy and Old River Rd. No damage was reported and it was rated an EF0.
Heavy Rain, Mariposa
- When
- May 9, 3:00 PM PST
- Where
- Mariposa County, 1.29 mi WSW of Yosemite Vlg
- Reported by
- Park/Forest Service
- Coordinates
- 37.740, -119.600
Heavy Rainfall with a total of 1.85 inches, reported by the Park Service.
Flood, Mariposa
- When
- May 9, 4:00 PM PST
- Where
- Mariposa County, 1.29 mi WSW of Yosemite Vlg to 1.28 mi S of Yosemite Vlg
- Cause
- Heavy Rain
- Reported by
- Park/Forest Service
- Coordinates
- 37.740, -119.600
The National Park Service reported minor road flooding. Heavy rainfall with total of 1.87 inches in only 30 minutes.
What these are
- Strong Wind
- Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.
- Tornado
- A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
- Heavy Rain
- Rainfall totals unusual for the place and season that did not produce a flood.
- Flood
- Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
More
Every storm in California in 2013Every state in 2013This day in weather historyThe tornado archive for California, 2013Warnings in California, May 2013
Sources
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: 457223, 510101, 510102, 510103.