Scattered showers and thunderstorms, moving generally to the west, formed mainly over Graham, Pima, and Pinal counties during the afternoon. As the storms moved through Tucson they caused flash flooding from Marana to southwest Tucson, and also produced wind damage in parts of the Tucson Metro.
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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 TWC wrote it up.
Scattered showers and thunderstorms, moving generally to the west, formed mainly over Graham, Pima, and Pinal counties during the afternoon. As the storms moved through Tucson they caused flash flooding from Marana to southwest Tucson, and also produced wind damage in parts of the Tucson Metro. Flash flooding also occurred in Ash Creek on Mt. Graham.
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 Tucson, AZ wrote its last area forecast discussion before the first event at Jul 19, 2:50 PM MST, 25 minutes earlier.
Area Forecast Discussion National Weather Service Tucson AZ 250 PM MST Wed Jul 19 2017 .SYNOPSIS...Scattered to numerous afternoon and evening thunderstorms will prevail through this weekend. The greatest thunderstorm coverage should occur east to south of Tucson with lesser thunderstorm activity west of Tucson. Below normal daytime temperatures will also prevail into the weekend. && .DISCUSSION...Another active afternoon across portions of southeast Arizona with storms firing across Cochise, Santa Cruz, Graham, eastern Pima and eastern Pinal counties so far. Expect shower and storm development to continue through the rest of the afternoon and into the evening hours tonight before diminishing. Overall, flash flood threat is down from the last couple of days with relatively fast steering flow/storm motion. Drier air noted earlier in the day on water vapor and Blended Total Precip Water imagery has overspread northern Greenlee and Graham counties and shut down convection for the time being in those areas. PW values in these areas have fallen into the 0.70-0.90 inch range with visible satellite imagery indicating just some flat cumulus clouds. Very little convective activity also noted upstream in western New Mexico under the core of drier air. Otherwise, storms are firing all along and out ahead of this dry air boundary residing over far eastern Cochise, Graham and southern Greenlee counties attm. Not much change in thinking with the forecast going forward. The western half of the state will begin to dry out Thursday and Friday, with the eastern half of the state remaining quite moist and active. A weak upper low/inverted trough is progged to move northward from Chihuahua, Mexico and set up along the Arizona/New Mexico border Thursday into Friday enhancing storm development across eastern portions of the forecast area. In addition, the brisk steering flow of today will become light Thursday into Friday, so storms that do form those days will have an increased flash flood potential. The overall pattern then shows very little change Saturday through Monday of next week, as deep moisture once again surges northward across the state increasing precipitation chances areawide, but especially from Tucson and points south and east. Some drying is then noted mid to late next week, but the latest models runs are not quite as aggressive with this drying. Grids/text products show a lowering of pops next Tuesday and Wednesday in response to this drying, especially west of Tucson. Daytime high temperatures will remain below normal into early next week and then near normal mid to late next week. && .AVIATION...Valid thru 21/00Z. Scattered to numerous TSRA/SHRA this afternoon/evening, then isolated to scattered -TSRA/-SHRA mainly west/northwest of KTUS late tonight into early Thursday morning. Scattered to numerous TSRA/SHRA developing again Thursday afternoon. Otherwise, VFR conditions with cloud decks generally 5k-10k ft AGL, and surface wind variable in direction mainly less than 12 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered to numerous mainly afternoon and evening thunderstorms will continue the rest of the work week with locally heavy rains. A bit of an uptick in the number of storms is likely later this weekend into early next week. Temperatures will remain below normal with a continuation of elevated humidity levels. 20- foot winds will mainly remain below 15 mph with the exception of strong outflow winds in the vicinity of thunderstorms. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && Zell Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Special Weather Statement
National Weather Service Tucson AZ
1222 PM MST WED JUL 19 2017
AZZ509-510-192015-
Upper Gila River and Aravaipa Valleys including Clifton/Safford-White
Mountains of Graham and Greenlee Counties including Hannagan Meadow-
1222 PM MST WED JUL 19 2017
...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL GREENLEE COUNTY UNTIL 115
PM MST...
At 1222 PM MST, Doppler radar was tracking a strong thunderstorm 10
miles east of Clifton, or 24 miles west of Buckhorn, moving west at
10 mph.
Half inch hail and wind gusts up to 50 mph will be possible with this
storm.
Locations impacted include...
Clifton, Morenci and Guthrie.
LAT...LON 3280 10928 3303 10947 3307 10914 3292 10904
3289 10905
TIME...MOT...LOC 1922Z 078DEG 11KT 3297 10912
LeinsSpecial Weather Statement National Weather Service Tucson AZ 155 PM MST WED JUL 19 2017 AZZ507-513-192200- Upper San Pedro River Valley including Sierra Vista/Benson-Dragoon/Mule/Huachuca and Santa Rita Mountains including Bisbee/Canelo Hills/Madera Canyon- 155 PM MST WED JUL 19 2017 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN COCHISE AND NORTHEASTERN SANTA CRUZ COUNTIES UNTIL 300 PM MST... At 155 PM MST, Doppler radar was tracking a strong thunderstorm over Huachuca City, or near Sierra Vista, moving northwest at 25 mph. Wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Sierra Vista, Benson, Huachuca City, Sierra Vista Southeast, Fort Huachuca, Charleston, Whetstone and Elgin. 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. 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 3159 11008 3148 11022 3175 11063 3193 11046 TIME...MOT...LOC 2055Z 129DEG 22KT 3165 11031 LEINS
Special Weather Statement National Weather Service Tucson AZ 315 PM MST WED JUL 19 2017 AZZ502-504>506-192315- Tohono O'odham Nation including Sells-Southeast Pinal County including Kearny/Mammoth/Oracle-Tucson Metro Area including Tucson/Green Valley/Marana/Vail-South Central Pinal County including Eloy/Picacho Peak State Park- 315 PM MST WED JUL 19 2017 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN PIMA AND SOUTH CENTRAL PINAL COUNTIES UNTIL 415 PM MST... At 315 PM MST, Doppler radar was tracking a strong thunderstorms near Tucson Estates and Marana, moving northwest at 5 mph. Wind gusts of 50 mph and blowing dust will be possible with this storm. Locations impacted include... Tucson, Marana, Flowing Wells, Avra Valley, Tucson Estates, Casas Adobes, Tortolita, Saguaro National Park West, Red Rock, Picture Rocks and Silver Bell. PRECAUTIONARY/PREPAREDNESS ACTIONS... Heavy rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3230 11100 3215 11121 3240 11162 3266 11124 TIME...MOT...LOC 2215Z 137DEG 6KT 3229 11117 French
The Tucson radar (KEMX), 80 km away, was scanning. The volume nearest the first event began at 22:12 UTC.
5 flash flood, 2 thunderstorm wind. Local standard time, as filed.
Marana ASOS measured a wind gust of 58 mph and a tree was down in the eastbound lane at I-10 and Tangerine Road.
Flash flooding caused Twin Peaks Road at Sanders Road to be closed.
A strong thunderstorm moved through the Tucson metro area during the afternoon with many reports of damage in central and western Tucson. The highest measured wind speed was 49 mph near 7th Street and Campbell. Large trees were uprooted along Kino Parkway and Silverlake Road, near Park and 20th Street, near Stone and 6th Street, near Echols Avenue and 5th Street, and near the McKale Center on the University of Arizona campus. The tree that fell on the U of A campus fell on two parked cars. There was also a power pole down at Speedway Boulevard and I-10.
Stone Street underpass was closed due to flash flooding to a depth of 8 feet.
Flash flooding caused Moore Road to be closed between Sanders Road and the I-10 frontage road as well as Tangerine Road at I-10. Another area of flash flooding caused Snyder Hill Road to be closed between Desert Sunrise and Sandario roads in southwest Tucson.
Flash flooding caused Hawser Street between Twin Lakes Drive and Coronado Forest Drive in Catalina to close.
Heavy rains fell across the Frye Fire burn scar and caused flash flooding in Ash Creek. An 8 pipeline leading to Cluff Pond 3 was washed away and several private outbuildings were damaged.
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, July 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: 711386, 711389, 711404, 711396, 711400, 711387, 711403.