An upper level disturbance combined with monsoonal moisture to create thunderstorms with heavy rains and some large hail. Debris flows, rock slides and local roadway flooding occurred in a few locations, including the Rim Fire burn area.
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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 STO wrote it up.
An upper level disturbance combined with monsoonal moisture to create thunderstorms with heavy rains and some large hail. Debris flows, rock slides and local roadway flooding occurred in a few locations, including the Rim Fire burn area.
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 Sacramento, CA wrote its last area forecast discussion before the first event at Jul 20, 8:36 AM PST, 1 hour 24 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 936 AM PDT Sun Jul 20 2014 .Synopsis... An upper level disturbance continues over northern California today with the greatest probability for thunderstorms over mountains. An offshore trough may trigger thunderstorms over Tehama, Shasta, and Plumas county area Monday and Tuesday. Then expect a warm up Wednesday through the weekend. && .Short Term Discussion (Today through Tuesday)... Monsoonal moisture continues to spread northward over the region today. Some sprinkles and light showers have are moving westward over the western portions of the valley and delta this morning. This activity is expected to decrease over the next couple of hours. A disturbance over the Central Sierra will move northward through the region on today along the crest. By noon thunderstorms may start to form again over the Sierra Nevada. Precipitable waters remain high so any thunderstorms that develop will likely contain very heavy rainfall. Most of the activity today is expected over the same general areas as the last couple of days with the best chance of storms over the western slopes remaining south of I-80 today. That disturbance will linger over the northern areas for Monday. That feature combined with a low pressure trough deepening along the coast may enhance activity over the northern areas both for Monday. Increased cloud cover for Sunday and Monday will bring cooler temperatures. The low will deepen along the coast on Tuesday and may continue to bring afternoon thunderstorms to the northern mountain areas as a weak disturbance moves through the region from the southwest. Good onshore flow will continue the next several days and temperatures will be below normal for this time of year. A trough will begin to move into the Pacific Northwest on Wednesday. Skies should be clearing and thunderstorm activity should be focused more north of the area and into Oregon. Temperatures should warm a little but still be below seasonal normals. .Extended Discussion (Thursday through Sunday) NorCal is under some form of benign southwesterly flow aloft into next weekend. The four corners high is forecast to gradually build northwestward back into NorCal for a significant warming trend beyond midweek. The monsoonal moisture will have exited and provide for a clearer sky and less humidity. Triple digit heat appears to return to portions of the Central Valley by Friday with additional warming through the weekend. We will need to watch for the potential of more monsoonal moisture to make its way into forecast area late in the period, but will keep a dry forecast for now. JClapp, Part Deux && .Aviation... VFR conditions over the Valley today with a band of iso -SHRA moving through this morning. SCT mountain thunderstorms will spread from south of I80 this morning to the Southern Cascades by around 21z. Gusts to 30 kt in the Delta. Erratic gusts to around 30kt near thunderstorms. && .STO Watches/Warnings/Advisories... None. &&
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
824 AM PDT SUN JUL 20 2014
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0905 PM HEAVY RAIN 1 ESE CHESTER 40.30N 121.22W
07/19/2014 M0.85 INCH PLUMAS CA TRAINED SPOTTER
HEAVY RAIN AND POWER OUTAGES WIND GUST TO 40
MPH
&&
NWS SACRAMENTO CA
IRIS SYSTEMThe Sacramento radar (KDAX), 176 km away, was scanning. The volume nearest the first event began at 17:59 UTC.
2 heavy rain, 2 debris flow, 1 flash flood, 1 hail. Local standard time, as filed.
Thunderstorms produced heavy rain over Rim Fire Burn scar. Storm total of 1.31 inches in 2 hours, heavy rain for 30 minutes.
Thunderstorms produced heavy rain over Rim Fire Burn scar. Storm total of 1.69 in, for approximately 2 hours.
Stream bank erosion, with some scouring, rilling, and sheet erosion. Sediment deposited in creek bed at multiple road/creek crossings. There was also float-able debris that was later removed. Road was over-topped at multiple locations. Estimated Granite Creek Basin flow of 1200 CFS, a very high amount for the basin. Flash flood duration of 2 hours and 30 minutes.
A strong thunderstorm produced quarter size hail. The ground was covered with 2 inches of hail.
Rocks on Highway 36 near Wildwood due to heavy rain. The roadway was flooded.
Rocks and mud slides on Highway 36 near Wildwood and Harrison Gulch roads due to torrential rain. Water was flowing on roads, along with accumulating hail.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2014Every state in 2014This day in weather historyWarnings in California, July 2014
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: 537672, 537673, 537670, 537629, 537662, 537655.