Moisture over Yavapai County triggered thunderstorms in the evening.
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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 FGZ wrote it up.
Moisture over Yavapai County triggered thunderstorms in the evening.
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 Flagstaff, AZ wrote its last area forecast discussion before the first event at Aug 1, 3:22 PM MST, 4 hours 15 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 322 PM MST Tue Aug 1 2017 .SYNOPSIS...Active conditions will remain in place along the Mogollon Rim and southward through the week. Drier and warmer conditions are expected near the Utah border. && .DISCUSSION...Scattered showers and thunderstorms are ongoing this afternoon with the greatest coverage along and south of I-40. Coverage and storm intensity will decrease after sunset with the loss of daytime heating. A strong ridge of high pressure centered to the northwest of the area will remain the dominant weather feature over the next few days. This will act to suppress the most widespread convection to the Mogollon Rim and southward with drier and warmer conditions near the Utah border. The ridge will begin to break down later in the week with a weak trough of low pressure developing off the coast of California. Models indicate this could advect drier air over northern Arizona resulting in even less thunderstorm activity by the weekend and early next week. Until there is some better model consistency, have continued with the previous forecast of chance pops along the Mogollon Rim and southward during this time frame with slight chance elsewhere. && .AVIATION...For the 00Z package...Scattered afternoon and evening thunderstorms will continue, decreasing in coverage and intensity after sunset. Local reductions in cig/vis possible in moderate to heavy RA. Another round of scattered showers and thunderstorms are forecast after 18Z Wednesday, with the greatest activity expected along and south of the Mogollon Rim, and in the White Mountains. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered showers and thunderstorms are forecast each day, favoring areas along the Mogollon Rim and White Mountains south into Yavapai and Gila Counties. Expect gusty winds near any storms, and areas of moderate to locally heavy rain. Friday through Sunday...Expect daily chances for showers and thunderstorms across all of northern Arizona, along with near normal temperatures. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...TPS AVIATION...RR FIRE WEATHER...RR For Northern Arizona weather information visit weather.gov/flagstaff
Hazardous Weather Outlook National Weather Service Flagstaff AZ 613 AM MST Tue Aug 1 2017 AZZ004>018-037>040-020345- Kaibab Plateau-Marble and Glen Canyons-Grand Canyon Country- Coconino Plateau-Yavapai County Mountains- Northeast Plateaus and Mesas Hwy 264 Northward-Chinle Valley- Chuska Mountains and Defiance Plateau- Little Colorado River Valley in Coconino County- Little Colorado River Valley in Navajo County- Little Colorado River Valley in Apache County- Western Mogollon Rim-Eastern Mogollon Rim-White Mountains- Northern Gila County-Yavapai County Valleys and Basins- Oak Creek and Sycamore Canyons-Black Mesa Area- Northeast Plateaus and Mesas South of Hwy 264- 613 AM MST Tue Aug 1 2017 This hazardous weather outlook is for Apache...Coconino... Northern Gila...Navajo...and Yavapai Counties in Northern Arizona. .DAY ONE...Today and Tonight High pressure building over Nevada will bring east to northeast flow back to the area today. This will cause storm activity to decrease north of I-40, while the southern portions of the area stay active. The most likely initial development will be over the White Mountains and Mogollon Rim later this morning, with storm motion to the west. This will bring activity into Yavapai, northern Gila and western Coconino counties by the late afternoon. .DAYS TWO THROUGH SEVEN...Wednesday through Monday A similar pattern will remain in place through at least Wednesday. This pattern will favor the southern portions of the area. The high pressure area begins to break down later in the week and into the weekend, allowing activity to push back northward. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures.
The Phoenix radar (KIWA), 145 km away, was scanning. The volume nearest the first event began at 02:35 UTC.
2 flash flood, 1 heavy rain. Local standard time, as filed.
The river gauge at Martinez Wash rose 2.2 feet (1730 CFS) due to heavy rain upstream.
The Yavapai Flood District Office reported one foot of water over area roads due to the heavy rain.
Thunderstorms produced heavy rain over the Prescott area. At one point, the rainfall rate was 9.22 inches per hour! It rained 1.89 inches in one hour.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2017Every state in 2017This day in weather historyWarnings in Arizona, 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: 719288, 719284, 719277.