Enough moisture remained over eastern Arizona to produce strong 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.
Enough moisture remained over eastern Arizona to produce strong 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 14, 3:23 PM MST, 1 hour 30 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 323 PM MST Mon Aug 14 2017 .SYNOPSIS...A few thunderstorms are expected the rest of this afternoon and early evening along and east of a line from Payson to Page, with dry conditions west of this line. A slight chance of storms will linger Tuesday near the White Mountains, with much drier and breezy conditions elsewhere. Dry weather will persist through at least Friday, with a chance of storms gradually returning for the weekend. && .DISCUSSION...Drier air aloft is moving into the state this afternoon and has shut off thunderstorm activity west of a Page to Payson line. East of this line, enough low level moisture remains for increased instability and scattered thunderstorms, some strong or severe. The most active areas for the rest of the afternoon are expected over portions of Apache County before dissipating this evening. The drier air to our west will continue to filter in Tuesday through the rest of the work week, with mostly sunny skies and the only chance of storms being Tuesday afternoon near the White Mountains. An upper trough moving through Tuesday will also bring gusty southwest winds of 15-25 mph. The trough will keep daytime temperatures a few degrees below normal, with overnight lows several degrees below normal due to the dry air mass. Models suggest a more favorable flow pattern for moisture return developing during the weekend, as high pressure becomes centered east of the state. We continue to advertise a slow increase in thunderstorm chances for the weekend but confidence remains low at this point. && .AVIATION...For the 00Z package...Expect sct shra/tsra and isold +tsra mainly east of a KRQE-KSJN line through 02Z. MVFR/IFR in the stronger storms. Mainly VFR conditions elsewhere with SW sfc winds 10-20kts. VFR all areas aft 02Z. SW sfc winds 15-25kts after 18Z Tuesday. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect dry and breezy conditions Tuesday and Wednesday. The only exception being a slight chance of showers and thunderstorms on Tuesday over the eastern White Mountains. Minimum relative humidity values will fall considerably from what has been seen the last few days. Thursday through Saturday... Dry conditions continue through much of this period, with lighter winds. Some moisture returns by Saturday, with a slight chance of showers and thunderstorms over the eastern zones. && && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...JJ AVIATION...Peterson FIRE WEATHER...Peterson For Northern Arizona weather information visit weather.gov/flagstaff
Hazardous Weather Outlook National Weather Service Flagstaff AZ 912 AM MST Mon Aug 14 2017 AZZ010>018-038>040-150200- 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-Oak Creek and Sycamore Canyons- Black Mesa Area-Northeast Plateaus and Mesas South of Hwy 264- 912 AM MST Mon Aug 14 2017 This hazardous weather outlook is for Apache...Coconino... Northern Gila...Navajo...and Yavapai Counties in Northern Arizona. .DAY ONE...Today and Tonight Scattered thunderstorms are expected this afternoon and early evening generally along and east of a Page to Flagstaff to Payson line. Some of the storms could become strong or locally severe, with hail and gusty winds. Locally heavy rainfall and flooding could develop in a few locations due to storms moving repeatedly over the same area. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Much drier air will end the chance of thunderstorms over most of northern Arizona Tuesday through at least Friday. A slight chance of storms returns to the region for the weekend. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures.
Special Weather Statement National Weather Service Flagstaff AZ 131 PM MST MON AUG 14 2017 AZZ013-142100- Little Colorado River Valley in Navajo County- 131 PM MST MON AUG 14 2017 ...SIGNIFICANT WEATHER ADVISORY FOR NAVAJO COUNTY SOUTH OF HOLBROOK UNTIL 200 PM MST... At 130 PM MST, Doppler radar was tracking a strong thunderstorm 8 miles southwest of Holbrook, or 31 miles southeast of Winslow, moving east at 15 mph. Half inch hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Holbrook and Woodruff. 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 3473 11029 3486 11035 3496 11010 3476 11003 TIME...MOT...LOC 2030Z 249DEG 11KT 3480 11024 MCT
Special Weather Statement National Weather Service Flagstaff AZ 420 PM MST MON AUG 14 2017 AZZ017-142345- White Mountains- 420 PM MST MON AUG 14 2017 ...SIGNIFICANT WEATHER ADVISORY FOR EAST OF PINETOP-LAKESIDE AREA IN APACHE AND NAVAJO COUNTIES UNTIL 445 PM MST... At 418 PM MST, Doppler radar was tracking a strong thunderstorm near Hondah, or 14 miles southeast of Show Low, moving northeast at 20 mph. Dime size hail and wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Hondah, Lake Of The Woods--Pinetop-lakeside, Pinetop Country Club, Los Burros Campground, Mcnary and Brown Creek 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 3395 10984 3401 10998 3426 10988 3418 10965 TIME...MOT...LOC 2318Z 203DEG 19KT 3410 10986 MCT
The Flagstaff radar (KFSX), 132 km away, was scanning. The volume nearest the first event began at 23:54 UTC.
1 hail. Local standard time, as filed.
A thunderstorm produced quarter sized (1 inch in diameter) hail with very heavy rain. Some stones were larger.
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: 720665.