Strong thunderstorm activity, fueled by MLCAPE values of around 1000 J/KG, developed across the Mogollon Rim and the White Mountains and were steered westward into Gila County. 5 inches in less than one hour, enough to result in flash flooding along the Sevenmile Wash, located northwest of San Carlos.
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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 PSR wrote it up.
Strong thunderstorm activity, fueled by MLCAPE values of around 1000 J/KG, developed across the Mogollon Rim and the White Mountains and were steered westward into Gila County. The strong thunderstorm activity produced rainfall amounts in excess of 1.5 inches in less than one hour, enough to result in flash flooding along the Sevenmile Wash, located northwest of San Carlos.
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 Aug 7, 4:20 PM MST, 10 minutes earlier.
Area Forecast Discussion National Weather Service Phoenix AZ 420 PM MST Wed Aug 7 2024 .Update...00Z Aviation Discussion && .SYNOPSIS... Thunderstorm chances will continue this afternoon and evening across south-central Arizona with the greatest chances across the higher terrain areas north and east of Phoenix. Thunderstorms will be capable of producing strong winds along with locally heavy rainfall. Rain chances will gradually diminish into the weekend with chances retreating to mainly over higher terrain areas by Saturday as drier air works into the region. Near to slightly below normal temperatures today and tomorrow will give way to warming temperatures heading into the weekend with highs likely topping out near or above 110 degrees across the lower deserts. && .DISCUSSION... The latest satellite WV imagery and RAP analysis showed an inverted trough situated over the northern Gulf of California near the international border with southwest Arizona and northern Mexico. Temperatures so far this afternoon are running around 5-10 degrees cooler compared to 24 hours ago with many lower desert areas still under the century mark early this afternoon. Highs this afternoon will generally top out between 100-106 degrees, which is near to slightly below normal for this time of year. Early afternoon satellite and radar showed convection along the Mogollon Rim along with a few storms popping up across southeast Arizona. Easterly steering flow around 10-15 kts will help push thunderstorms off the Rim and into southern Gila County through this afternoon into the early evening hours. MUCAPE values upwards of 1000-1500 J/kg along with DCAPE values around 1000-1500 J/kg may support some stronger to perhaps isolated severe thunderstorms capable of producing strong downbursts. HREF paintball plots show good confidence in thunderstorms developing across southern Gila County this afternoon/evening with less confidence in thunderstorms surviving into the lower deserts. Thunderstorm development into the lower deserts will have to contend with greater CIN, which will prove difficult to overcome without some good outflows. However, strong/deep and/or colliding outflows could be enough to overcome some of this inhibition to pop off a few thunderstorms across the Valley. Several 12Z HREF members indicate this possibility, showing isolated showers and thunderstorms surviving into parts of the south-central Arizona lower deserts. There is better confidence in thunderstorm development across far northern portions of Maricopa County, including the northern foothills and the Wickenburg area. Any stronger thunderstorms that were to develop across the lower deserts this evening would be capable of producing strong downbursts, which could lead to blowing dust, and locally heavy rainfall. In terms of rainfall, the 12Z HREF suggests a greater chance of seeing some locally heavy rainfall amounts across southern County where there is about a 50% chance of seeing 3 hour QPF exceed 1". Thus, isolated instances of flash flooding will be possible. .PREVIOUS DISCUSSION... Starting Thursday, guidance still favors some drying to begin across the western deserts and this should end chances for rain west of the CO River. Decent monsoon moisture should still persist across south-central and eastern Arizona, so it's likely we will see another day of isolated to scattered afternoon convection. By Friday into Saturday, drier air is expected to filter into the rest of southern and central Arizona from the southeast and this should lower storm chances further mainly limiting any convection to higher terrain areas. At the same time, the subtropical high which is forecast to shift into the Southern Plains over the next couple of days is expected to strengthen and expand back into our region. As H5 heights rise to around 594-596dm by Saturday and we lose boundary layer moisture, temperatures will warm Friday into Saturday with highs likely reaching 110-114 degrees across the lower deserts Saturday. This may result in some areas of Major HeatRisk on Saturday and potentially on Sunday before the subtropical high begins to weaken again into early next week. There are also signs of some improving moisture again by around next Monday and if this comes to fruition it may mark another increase in monsoon activity. && .AVIATION...Updated at 2320Z. South Central Arizona including KPHX, KIWA, KSDL, and KDVT: No major aviation concerns are expected during the TAF period. Winds should follow typical diurnal trends, with a few gusts this evening in the mid-teens. There are hints of a weak outflow from distant thunderstorm activity working its way through the metro, potentially disrupting the usual winds trends but overall confidence in any wind shifts related to this feature are low at this time. An isolated shower or thunderstorm in the vicinity of the terminals cannot be completely ruled out but most activity should remain off to the north and east. SCT to BKN skies will prevail through tonight, with the lowest bases around 10k ft. Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected during the TAF period. Winds at IPL will be primarily out of the SE but a brief switch to the SW is possible early tonight. At BLH, familiar diurnal trends should prevail, with gusts this evening around 20 kts. FEW-SCT mid and high level clouds will be present through tomorrow morning, before coverage decreases by the afternoon. && .FIRE WEATHER... Isolated to scattered showers and thunderstorms are expected this afternoon across the Arizona high terrain with lower chances across the Arizona lower deserts. The primary concern with thunderstorms will continue to be strong, erratic outflow winds with up to a 50-70% chance of winds to exceed 35 mph across south- central Arizona. Locally heavy rainfall may also accompany thunderstorms, especially across southern Gila County. Thunderstorm chances continue again Thursday afternoon with gusty, erratic outflows remaining the primary concern, before a drying for the end of the week leads to decreasing thunderstorm chances, particularly across the lower elevations. Outside of thunderstorms, winds will overall favor diurnal tendencies. Min RHs will be around 20-40% and Max RHs around 40-70% over the next couple of days, with a gradual drying trend occurring for the end of the week. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && DISCUSSION...Smith PREVIOUS DISCUSSION...Kuhlman AVIATION...RW FIRE WEATHER...Smith/Kuhlman
Preliminary Local Storm Report
National Weather Service Phoenix AZ
1247 PM MST Wed Aug 7 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0636 PM Dust Storm 3 ENE Arizona City 32.78N 111.62W
08/06/2024 Pinal AZ NWS Employee
Visibility reduced below one quarter mile
from blowing dust.
&&
TWPreliminary Local Storm Report
National Weather Service Phoenix AZ
101 PM MST Wed Aug 7 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0704 PM Dust Storm 13 SE Ak-Chin Village 32.88N 111.96W
08/06/2024 Pinal AZ Emergency Mngr
Visibility reduced to approximately 300 feet
from blowing dust.
&&
TWPreliminary Local Storm Report
National Weather Service Phoenix AZ
133 PM MST Wed Aug 7 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0905 PM Tstm Wnd Dmg 2 NE Paradise Valley 33.55N 111.92W
08/06/2024 Maricopa AZ Broadcast Media
Approximately 30 trees were uprooted at the
McCormick Ranch Golf Club.
&&
TWThe Phoenix radar (KIWA), 107 km away, was scanning. The volume nearest the first event began at 23:30 UTC.
1 flash flood. Local standard time, as filed.
Sevenmile Wash rose approximately 2 ft, making low water crossings across the wash impassable. Timing estimated from radar estimated precipitation. No damages nor injuries were reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2024Every state in 2024This day in weather historyWarnings in Arizona, August 2024
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: 1206088.