Beginning around midday and continuing through afternoon, slow-moving isolated thunderstorms developed over Joshua Tree National Park, which sits at higher elevation. A few of the storms produced high rainfall rates and localized radar estimated rainfall amounts up to around 2 inches.
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 PSR wrote it up.
Beginning around midday and continuing through afternoon, slow-moving isolated thunderstorms developed over Joshua Tree National Park, which sits at higher elevation. A few of the storms produced high rainfall rates and localized radar estimated rainfall amounts up to around 2 inches. This led to at least one report of flash flooding in the park.
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 Phoenix, AZ wrote its last area forecast discussion before the first event at Sep 28, 10:02 AM PST, 1 hour 19 minutes earlier.
Area Forecast Discussion National Weather Service Phoenix AZ 1102 AM MST Wed Sep 28 2022 .UPDATE...18Z Aviation Discussion... && .SYNOPSIS... Moisture will continue to linger across the area through the rest of the week, with slight chances of showers and storms that will favor the high terrain generally south and east of the Phoenix area. The above average temperatures, but slight cooling of a couple degrees will be the trend going into the weekend. && .DISCUSSION... Although temperatures are expected to remain above average, an upper level trough entering the Pacific Northwest this morning will aid in slightly cooling temperatures across the area over the next several days as this trough advances east-southeastward. These cooler temperatures are resulting in only a Moderate HeatRisk for areas across western Imperial County, while everywhere else is generally under Minor HeatRisk during this time period. The best moisture and instability continues to linger across southwest AZ and southeast CA for today. There are more expansive 10-20% NBM PoPs for this afternoon through the early morning hours Thursday across this general area, with isolated showers and thunderstorms favoring higher terrain. Although the moisture and instability are limited, the main storm threats for today will be gusty winds and the potential for localized blowing dust. Measurable rainfall will be very sparse, but a few localized areas under any stronger cells could see a half an inch or more of rain. Model ensembles show the Pacific trough slowly tracking east southeastward through the Northern Rockies and Great Basin by the end of the week, with weak westerly flow aloft developing by Saturday across southern Arizona. Lingering moisture across our region should still result in limited chances for showers and possibly isolated thunderstorms for the rest of this week, but eventually enough dry air is expected to spread over our area that rain chances mostly come to an end by early next week. && .AVIATION...Updated 18Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Elevated easterly winds will continue this morning with some gusts to around 20kts through mid-afternoon. Winds will shift a bit more out of the southeast and possibly out of the south for a few hours this afternoon as distant showers and storms south of Phoenix may send weak outflows northward into the Phoenix area. Can't completely rule out a shower or even a weak thunderstorm in the Phoenix area this afternoon/early evening, but chances are at most 10%. Winds are then expected to revert back to more typical easterly drainage winds around/shortly before midnight. Southeast California/Southwest Arizona including KIPL and KBLH: No significant weather issues are expected through the TAF period with occasional SCT midlevel decks. Winds at KBLH will eventually turn southerly, while southeasterly winds are mostly likely at KIPL. There may also be some isolated gusts in the teens at both terminals this afternoon. There should also be some widely isolated showers and thunderstorms across the area this afternoon/early evening, but the chances are quite low (10-15%), so not included in TAFs. && .FIRE WEATHER... Above normal temperatures will continue through the rest of the week, although slight cooling will occur going into the weekend. Modest moisture across the western districts will provide chances for isolated showers and thunderstorms through at least Wednesday over higher terrain areas across southeastern CA and southwestern AZ. Drying conditions by early next week will mostly end rain chances across the majority of the area as high pressure rebuilds across the region. Afternoon MinRHs through the end of the week will mostly be between 15-25% each day, although slight increases in MinRHs are expected going through the weekend. Enhanced easterly winds are likely to prevail across much of southern Arizona through today with morning gusts up to 25 mph. Winds later this week should shift back to a more typical diurnal pattern with lighter winds speeds. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && DISCUSSION...Young AVIATION...Feldkircher/Kuhlman FIRE WEATHER...Young
The Santa Ana Mts radar (KSOX), 140 km away, was scanning. The volume nearest the first event began at 19:18 UTC.
1 flash flood. Local standard time, as filed.
A park employee with Joshua Tree National Park share video and report of roads washed out in the Indian Cove section of the park. No damages or injuries were reported. Timing based on radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2022Every state in 2022This day in weather historyWarnings in California, September 2022
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: 1058653.