High pressure across the Great Basin brought enough moisture back over Arizona for widely scattered showers and thunderstorms.
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.
High pressure across the Great Basin brought enough moisture back over Arizona for widely scattered showers and thunderstorms.
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 27, 2:40 PM MST, 3 hours 41 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 240 PM MST Sun Aug 27 2017 .SYNOPSIS...Expect widely scattered afternoon and evening showers and thunderstorms this weekend and into next week. Daily high temperatures will remain above normal. && .DISCUSSION... High pressure across the Great Basin will continue over the next few days. Adequate moisture will persist under this flow regime for widely scattered showers and thunderstorms to develop each day, mainly during the afternoon and early evening hours. Light winds and daytime temps a bit above normal look to persist, especially north of the Mogollon Rim where highs will be near 10 degrees above late August averages. Low to mid grade monsoon forecast through the week. && .AVIATION...For the 00Z package...Isolated shower and thunderstorm activity across northern Arizona will diminish after 03Z. Expect wind gusts of 35-45 kts in the vicinity of storms. Look for another round of scattered showers and thunderstorms on Monday. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...For Monday and Tuesday, expect scattered showers and thunderstorms over the Mogollon Rim, White Mountains and locations to the south. Elsewhere, activity will be isolated. Light winds in addition to near normal temperatures and humidity continuing. Wednesday through Friday...The threat for isolated showers and thunderstorms will continue. Winds will remain light. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...KD AVIATION...McCollum FIRE WEATHER...McCollum For Northern Arizona weather information visit weather.gov/flagstaff
Hazardous Weather Outlook National Weather Service Flagstaff AZ 617 AM MST Sun Aug 27 2017 AZZ004>018-037>040-280200- 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- 617 AM MST Sun Aug 27 2017 This hazardous weather outlook is for Apache...Coconino... Northern Gila...Navajo...and Yavapai Counties in Northern Arizona. .DAY ONE...Today and Tonight Isolated afternoon and early evening showers and thunderstorms are expected, with scattered coverage over portions of Mogollon Rim and White Mountains. .DAYS TWO THROUGH SEVEN...Monday through Saturday Isolated to scattered afternoon and evening showers and thunderstorms are expected each day. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated at this time.
Special Weather Statement
National Weather Service Flagstaff AZ
424 PM MST SUN AUG 27 2017
AZZ008-037-280000-
Yavapai County Valleys and Basins-Yavapai County Mountains-
424 PM MST SUN AUG 27 2017
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWEST YAVAPAI COUNTY UNTIL
500 PM MST...
At 421 PM MST, Doppler radar was tracking thunderstorms along a line
extending from Bagdad to near Walnut Grove. Movement was southwest
at 15 mph.
Wind gusts of 40 to 50 mph will be possible with these storms. Brief
heavy rainfall could also lead to ponding water on area roads.
Locations impacted include...
Congress, Kirkland, Bagdad, Yava, Yarnell, Peeples Valley and Glen
Ilah.
LAT...LON 3446 11333 3469 11318 3441 11255 3405 11269
3437 11333
TIME...MOT...LOC 2321Z 025DEG 16KT 3457 11317 3434 11259
JJSpecial Weather Statement National Weather Service Flagstaff AZ 500 PM MST SUN AUG 27 2017 AZZ008-037-280045- Yavapai County Valleys and Basins-Yavapai County Mountains- 500 PM MST SUN AUG 27 2017 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWEST YAVAPAI COUNTY UNTIL 545 PM MST... At 459 PM MST, Doppler radar was tracking strong thunderstorms along a line extending from 13 miles south of Bagdad to 7 miles south of Wagoner. Movement was south at 15 mph. Winds in excess of 40 mph will be possible with these storms. Locally heavy rainfall amounts up to one inch will also cause ponding of water on roads and flowing washes. Locations impacted include... Congress, Wagoner, Yarnell, Peeples Valley and Glen Ilah. LAT...LON 3452 11332 3421 11237 3392 11243 3416 11333 TIME...MOT...LOC 2359Z 010DEG 18KT 3439 11326 3412 11249 JJ
Special Weather Statement National Weather Service Flagstaff AZ 526 PM MST SUN AUG 27 2017 AZZ016>018-280115- Northern Gila County-White Mountains-Eastern Mogollon Rim- 526 PM MST SUN AUG 27 2017 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHEAST GILA AND EXTREME SOUTHERN NAVAJO COUNTIES UNTIL 615 PM MST... At 522 PM MST, Doppler radar was tracking strong thunderstorms along a line extending from 11 miles southeast of Forest Lakes to near North Fork. Movement was southwest at 10 mph. Winds in excess of 40 mph will be possible with these storms. These storms are also producing heavy rainfall of up to one inch in less than an hour. Ponding of water on roads and flowing water through washes and streams is likely. Locations impacted include... Carrizo, Rainbow City, Cedar Creek, Fort Apache Reservation, North Fork, Whiteriver, Canyon Day and Cibecue. PRECAUTIONARY/PREPAREDNESS ACTIONS... Heavy rainfall is also occurring with these storms, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3405 11098 3377 11003 3401 10990 3425 11078 TIME...MOT...LOC 0022Z 025DEG 10KT 3421 11068 3394 10993 JJ
Special Weather Statement
National Weather Service Flagstaff AZ
557 PM MST SUN AUG 27 2017
AZZ008-015-016-018-037-038-280145-
Yavapai County Valleys and Basins-Western Mogollon Rim-Northern Gila
County-Yavapai County Mountains-Oak Creek and Sycamore
Canyons-Eastern Mogollon Rim-
557 PM MST SUN AUG 27 2017
...LINE OF SHOWERS AND THUNDERSTORMS WITH WIND GUSTS OVER 40 MPH AND
LOCALLY HEAVY RAIN MOVING INTO NORTHERN GILA AND EASTERN YAVAPAI
COUNTIES THROUGH 645 PM...
At 554 PM MST, Doppler radar was tracking strong thunderstorms along
a line extending from near Slide Rock State Park to 9 miles southwest
of Happy Jack to near Mead Ranch to near Haigler Creek. Movement was
west at 15 mph.
Winds in excess of 40 mph and locally heavy rain will be possible
with these storms.
Locations impacted include...
Payson, Camp Verde, Sedona, Clarkdale, Star Valley, Mcguireville,
Cherry, Bridgeport, Geronimo Estates, Strawberry, East Verde Estates,
Middle Verde, Flowing Springs, Pine, Mead Ranch, Lake Montezuma,
Verde Village, Haigler Creek, Village of Oak Creek and Mesa Del
Caballo.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Heavy rainfall is also occurring with these storms, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3490 11229 3456 11202 3428 11168 3405 11127
3416 11075 3435 11111 3460 11147 3500 11181
TIME...MOT...LOC 0054Z 096DEG 14KT 3494 11184 3463 11148 3432 11121
3419 11090
JJThe Flagstaff radar (KFSX), 72 km away, was scanning. The volume nearest the first event began at 01:21 UTC.
2 thunderstorm wind. Local standard time, as filed.
Wind gusts to around 50 MPH broke small tree branches (less than 2 inches in diameter). The winds also produced blowing dust that reduced the visibility.
High winds from a thunderstorm knocked down power lines on Sycamore Canyon Road near Tuzigoot National Monument.
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: 720667, 720668.