Subtropical moisture continued to stream into central California on July 30. Once again, afternoon thunderstorms developed over the Sierra Nevada.
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 HNX wrote it up.
Subtropical moisture continued to stream into central California on July 30. Once again, afternoon thunderstorms developed over the Sierra Nevada. One thunderstorm produced a fatal lightning strike over the Sierra Nevada during the early afternoon.
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 Jul 30, 11:29 AM PST, 1 hour 31 minutes earlier.
Area Forecast Discussion National Weather Service Hanford CA 1229 PM PDT Fri Jul 30 2021 .SYNOPSIS... Above average temperatures to continue over the forecast area due to high pressure aloft. Monsoonal moisture will fuel the Sierra Nevada and parts of Kern County with a chance of showers and thunderstorms through the weekend, with heavy rain possible. Dry weather is forecast to resume next week along with warm afternoon highs. && .DISCUSSION... Latest GOES-17 satellite imagery shows a well-defined feed of sub-tropical moisture entering the area with developing showers and thunderstorms over the Sierra Nevada and Tehachapi Mountains. This moisture tap is sending Precipitable Water (PWAT) values well above normal for today, and will persist through tomorrow. This moisture feed is coming from an off-shore low that is phased with an upper level ridge located over the Plains, giving storms access to abundant moisture. With the above average moisture comes with it the potential for heavy rainfall in thunderstorms. Flash Flooding will be possible this afternoon in thunderstorms, especially in slow-moving thunderstorms. For tomorrow, the HREF ensemble max remains fairly bullish over the Sierra Nevada due to the continued moisture feed. This remains consistent with previous thinking, so no changes were made to the existing Flash Flood Watch. Sunday will see a reduction in shower and thunderstorm coverage as the trough of low pressure that is currently offshore moves eastward, giving us southwesterly flow that will push the moisture feed to our east. There will be a chance for some thunderstorms along the Sierra Crests, but not seeing a risk for heavy downpours in these storms. After Sunday, ensemble guidance is showing a ridge of high pressure building over the area. This will lead to a much drier atmosphere, with continued above average afternoon high temperatures. && .AVIATION... Mountain obscurations in showers and scattered thunderstorms possible over the Sierra Nevada until 03Z Saturday. Also expect isolated to scattered thunderstorms with local MVFR ceilings and visibility possible at times over the Kern County mountains and desert during this afternoon and evening. Otherwise, VFR conditions will prevail through the next 24 hours. && .AIR QUALITY ISSUES... On Friday July 30 2021... Unhealthy for sensitive groups in Fresno... Kern... Madera... Merced and Tulare Counties and Sequoia National Park and Forest. Further information is available at Valleyair.org && .CERTAINTY... The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is high. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information an/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through Saturday evening for CAZ192>196. && public...Bollenbacher aviation....Bollenbacher weather.gov/hanford
The San Joaquin Valley radar (KHNX), 125 km away, was scanning. The volume nearest the first event began at 21:02 UTC.
1 lightning. Local standard time, as filed.
The Fresno County Sherrifs Office reported a 37 year old male hiker on the John Muir Trail near Muir Trail Ranch was struck by lightning and killed during a thunderstorm around 200 pm PDT on July 30.
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 |
|---|---|---|---|---|---|
| Lightning, Fresno | 2021-07-30 | 37 | Male | Under Tree | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2021Every state in 2021This day in weather historyWarnings in California, July 2021
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: 964357.