A weak weather disturbance will brought isolated thunderstorms to northern Arizona.
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 FGZ wrote it up.
A weak weather disturbance will brought isolated thunderstorms to northern Arizona.
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 23, 10:24 PM MST, 1 hour 31 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 1024 PM MST Wed Aug 23 2017 .SYNOPSIS...A weak weather disturbance will bring scattered shower and thunderstorm activity to much of northern Arizona through Thursday. Widely scattered showers and thunderstorms are expected over the high terrain Friday and Saturday. && .UPDATE...It has been an active evening of showers and thunderstorms over much of northern Arizona, continuing into the late evening hours. Increasing moisture combined with a weak disturbance have kept the activity going. Main threat is flooding in localized areas, with a lower threat of hail. Updated forecasts earlier for higher rain chances most areas. && .PREV DISCUSSION /322 PM MST/...Progs continue to show slight cooling aloft on Thursday due to a low pressure system moving through the Great basin. Still expecting primarily isolated showers and tstorm coverage for most of the area, though the eastern Mogollon Rim and White Mountains should see scattered coverage. For Friday and the weekend, high pressure aloft to redevelop over the desert southwest Friday and then become centered over Nevada for the weekend. Friday should feature just a chance of an afternoon storm over the high country. Cross sections indicate low and mid level winds to become east-southeast with time late Friday and bring a slow increase in moisture and instability. Storm chances were added to areas along and south of I-40 on Saturday. Drier northerly flow aloft on Sunday should limit storm chances to the White Mountains. Monday and Tuesday...Models continue to show Monsoon moisture making a comeback, pushed northward by an increase in thunderstorm activity over northwest Mexico. At this time the best chances still look to be from the Mogollon Rim southward. && .AVIATION...For the 06Z package...VFR conditions will prevail over most of northern Arizona through the 24 hr period. Scattered thunderstorms expected near KFLG, KGCN, KINW and KPGA this evening ending around 07z with MVFR/IFR conditions in the stronger storms. Another round of scattered thunderstorms are forecast Thursday afternoon that will affect the area terminal aerodromes. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered thunderstorms this afternoon will continue to favor the Eastern Rim and White Mountains. For Thursday afternoon, thunderstorm chances will spread west across the entire Mogollon Rim and Coconino Plateau. Mainly dry conditions are forecast over northern Arizona Friday, with thunderstorm chances confined to the White Mountains. Saturday through Monday...Afternoon thunderstorms are forecast to remain confined to the White Mountains Saturday and Sunday, with thunderstorm chances gradually increasing along the Mogollon Rim Monday. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...JJ/DL AVIATION...DB FIRE WEATHER...TM For Northern Arizona weather information visit weather.gov/flagstaff
Hazardous Weather Outlook National Weather Service Flagstaff AZ 326 AM MST Wed Aug 23 2017 AZZ004>018-037>040-240415- 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- 326 AM MST Wed Aug 23 2017 This hazardous weather outlook is for Apache...Coconino... Northern Gila...Navajo...and Yavapai Counties in Northern Arizona. .DAY ONE...Today and Tonight Look for isolated showers and thunderstorms over most of northern Arizona. Further east, over the eastern Mogollon Rim into the White Mountains, storms will be more numerous. Lightning will be the primary hazard. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Isolated to scattered showers and thunderstorms will continue on Thursday. Mainly dry conditions are expected for Friday and over the weekend. Increasing monsoon moisture will result in a better chance of showers and thunderstorms heading into Monday and Tuesday of next week. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated at this time.
Special Weather Statement National Weather Service Flagstaff AZ 741 PM MST WED AUG 23 2017 AZZ006-007-240315- Coconino Plateau-Grand Canyon Country- 741 PM MST WED AUG 23 2017 ...STRONG THUNDERSTORM APPROACHING TUSAYAN AND HIGHWAY 64... At 739 PM MST, Doppler radar was tracking a strong thunderstorm 10 miles north of Valle, or 5 miles south of Tusayan, moving northeast at 25 mph. Half inch hail and winds in excess of 30 mph will be possible with this storm. Locations impacted include... Ten-x Campground, Highway 64 from Tusayan to 10 miles south of Tusayan. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 3571 11219 3585 11233 3600 11205 3582 11186 TIME...MOT...LOC 0239Z 237DEG 21KT 3579 11219 JJ
Special Weather Statement National Weather Service Flagstaff AZ 835 PM MST WED AUG 23 2017 AZZ018-240400- Northern Gila County- 835 PM MST WED AUG 23 2017 ...Strong thunderstorms moving into Payson through 9 PM... At 834 PM MST, Doppler radar was tracking a strong thunderstorm over Payson, moving northwest at 15 mph. Half inch hail and winds in excess of 30 mph will be possible with this storm. Locations impacted include... Payson, Oxbow Estates, Round Valley, Flowing Springs, East Verde Estates, Mesa Del Caballo and Houston Mesa Campground. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3418 11120 3412 11130 3427 11149 3436 11135 TIME...MOT...LOC 0334Z 147DEG 14KT 3422 11135 JJ
Special Weather Statement National Weather Service Flagstaff AZ 1055 PM MST WED AUG 23 2017 AZZ008-037-038-240630- Yavapai County Valleys and Basins-Yavapai County Mountains-Oak Creek and Sycamore Canyons- 1055 PM MST WED AUG 23 2017 ...SIGNIFICANT WEATHER ADVISORY FOR COTTONWOOD AND VICINITY UNTIL 1130 PM MST... At 1054 PM MST, Doppler radar was tracking a strong thunderstorm over Bridgeport and Cottonwood, or 12 miles northwest of Camp Verde, moving northwest at 10 mph. Half inch hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Clarkdale, Verde Village, Bridgeport, Cottonwood, Cornville, Page Springs, Jerome, Dead Horse Ranch State Park and Tuzigoot National Monument. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 3472 11184 3463 11197 3473 11213 3486 11199 TIME...MOT...LOC 0554Z 135DEG 7KT 3472 11198 JJ
The Flagstaff radar (KFSX), 75 km away, was scanning. The volume nearest the first event began at 06:53 UTC.
1 flash flood. Local standard time, as filed.
Cottonwood Police Department reported flooding in homes in several areas in Cottonwood.
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: 720666.