Although a drier southwest flow became prevalent over Central California on August 5th, there was still enough moisture over the region for thunderstorms to develop over the higher elevations of the Southern Sierra Nevada. One thunderstorm produced flash flooding near Tuolumne Meadows on SR 120.
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The episode as NWS HNX wrote it up.
Although a drier southwest flow became prevalent over Central California on August 5th, there was still enough moisture over the region for thunderstorms to develop over the higher elevations of the Southern Sierra Nevada. One thunderstorm produced flash flooding near Tuolumne Meadows on SR 120.
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 5, 11:39 AM PST, 3 hours 51 minutes earlier.
Area Forecast Discussion National Weather Service San Joaquin Valley - Hanford CA 1239 PM PDT Sat Aug 5 2017 .SYNOPSIS...Slightly above normal temperatures and dry weather will be present across central California into next weekend. The one exception will be the Sierra Nevada...where thunderstorms will be possible each afternoon and evening through Tuesday. && .DISCUSSION...Mid level moisture continues to surge north northwest into central California this afternoon. This moisture in combination with weak surface and mid level instability will result in thunderstorms across the southern and central Sierra Nevada this afternoon into the evening hours. The high res models are in good agreement that the strongest storms will be present later this afternoon over the highest elevations of Fresno and Tulare counties...possibly impacting Sequoia and Kings Canyon National Parks. Those planning on hiking this afternoon are advised to monitor the weather closely and alter your plans if you hear thunder. Little change in the upper weather pattern through at least the middle of next week with a broad upper trough impacting northern and central California. This will result in near normal to slightly above normal temperatures through the end of next week. Thunderstorms will be possible over the Sierra through at least the beginning of next week...however chances are decreased each day from Sunday through Tuesday. Mid and upper level winds become westerly on Sunday and increase in strength into early next week...shifting all mid level moisture to the east. Lastly...according to the Climate Prediction Centers 8 to 14 day outlook (valid from August 13th through 19th) there is about a 40 percent chance of above normal temperatures. Point being...it is not set in stone that we will continue to see above normal temperatures. && .AVIATION... Scattered showers and thunderstorms with areas of MVFR and local IFR in mountain obscurations can be expected over the Sierra during the next 24 hours. VFR conditions will prevail elsewhere across the central California interior. && .AIR QUALITY ISSUES... On Saturday August 5 2017... Unhealthy for sensitive groups in Kern County. Further information is available at Valleyair.org && .CERTAINTY... The level of certainty for days 1 and 2 is medium. 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.php for additional information an/or to provide feedback. && .HNX Watches/Warnings/Advisories... NONE. && public...Riley avn/fw...Andersen synopsis...Riley weather.gov/hanford
The San Joaquin Valley radar (KHNX), 168 km away, was scanning. The volume nearest the first event began at 23:31 UTC.
1 flash flood. Local standard time, as filed.
Yosemite National Park rangers reported that Raisin Creek flooded causing debris on SR 120 (Tioga Pass Road) near Murphy Creek.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2017Every state in 2017This day in weather historyWarnings in California, August 2017
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: 717802.