Isolated to scattered showers and thunderstorms formed across southeast Arizona. Heavy rain from storms caused flash flooding on the east side of Tucson and caused damage to a building in Ajo.
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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.
Isolated to scattered showers and thunderstorms formed across southeast Arizona. Heavy rain from storms caused flash flooding on the east side of Tucson and caused damage to a building in Ajo.
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 31, 2:06 PM MST, 49 minutes earlier.
Area Forecast Discussion National Weather Service Tucson AZ 206 PM MST Wed Jul 31 2019 .SYNOPSIS...Temperatures will remain below normal this afternoon with scattered to numerous showers and thunderstorms, some of which will produce heavy rainfall. Thursday into the weekend there will be less shower and thunderstorm activity with temperatures climbing above average again by Friday with the above normal temperatures continuing for the weekend. && .DISCUSSION...Deep moisture with precipitable water values of 1.5 to 2 inches across much of southeast Arizona is resulting in a busy afternoon with scattered to numerous showers and thunderstorms. These have developed in the areas that had ample sunshine this morning allowing the atmosphere to destabilize with MLCAPE values of 1000-2000 J/kg. The storms we've seen so far today have been efficient rainfall producers with up to 0.75 inches in less than 30 minutes. With only around 10 kts of mean southerly mid level steering flow on the east side of a weak trough extending from the Gulf of California into the western deserts, the thunderstorms are moving slow enough that excessive rainfall and areas of flash flooding will be the main concern throughout the afternoon. An isolated severe thunderstorm is possible especially with cell mergers with wet microbursts being the main threat. The Tucson Metro was somewhat worked over from the light showers that went through earlier which means that with increased anvil shading now moving in that thunderstorm coverage might be a bit lacking. However, just peaking at the latest KEMX radar imagery, it is a bit more hopeful so perhaps we can squeak out a few storms in the Tucson Metro. Otherwise, unlike the past couple of days we should see much of the shower and thunderstorm activity start to diminish after sunset. A reduction in shower and thunderstorms to a more typical regime is expected starting Thursday and into the weekend. The high pressure will still remain in a fairly favorable position from New Mexico into the Four Corners region with east to southeasterly flow aloft and more typical moisture values for early August. Therefore, expect mainly afternoon and evening isolated to scattered shower and thunderstorm coverage mainly east of a line from about Eloy-Sells- Sasabe through the weekend. An uptick in the monsoon is possible around Tuesday/Wednesday of next week as a possible inverted trough to our south influences the region but confidence is still a bit low in this scenario. Temperatures will be below normal today by about 5 to 8 degrees but then moderate back up to normal levels on Thursday. Thereafter, temperatures will continue to warm with highs a few degrees about 3 to 6 degrees above normal Friday through Monday. && .AVIATION...Valid through 02/00Z. Scattered to numerous SHRA/TSRA across the region during the afternoon and evening. Thunderstorms and showers should generally move north of all terminals by 01/02Z. Wind gusts around 40 kts are possible along with brief MVFR cigs/vsbys with any storm. Outside of TSRA winds, expect generally westerly winds of 4-9 kts during the afternoon then becoming light and variable again overnight. Isolated to scattered thunderstorms and showers return Thursday afternoon but should generally remain east of KTUS and KOLS. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered to numerous showers and thunderstorms continuing this afternoon. Isolated to scattered storms will generally be expected in Graham and Greenlee counties late this evening as they move to the north. This added moisture/storm activity will result in below average high temperatures this afternoon, recovering to near normal Thursday, with minimum humidities that hover in the 30s across the lower deserts. 20-foot winds are generally from the west and under 10 mph today except near thunderstorms where gusty outflows are expected. Conditions start drying up Thursday with minimum humidities approaching 20 pct in lower elevations starting Friday. 20-foot winds will remain generally light and terrain driven through the afternoons. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
1155 AM MST WED JUL 31 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1153 AM HEAVY RAIN 4 N HUACHUCA CITY 31.69N 110.35W
07/31/2019 M0.70 INCH COCHISE AZ TRAINED SPOTTER
TRAINED SPOTTER REPORTED 0.70 INCHES OF RAIN
FALLING IN 12 MINUTES.
&&
MPSpecial Weather Statement National Weather Service Tucson AZ 1208 PM MST Wed Jul 31 2019 AZZ508-513-311945- Dragoon/Mule/Huachuca and Santa Rita Mountains including Bisbee/Canelo Hills/Madera Canyon-Eastern Cochise County Below 5000 Feet including Douglas/Willcox- 1208 PM MST Wed Jul 31 2019 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL COCHISE COUNTY UNTIL 1245 PM MST... At 1208 PM MST, Doppler radar was tracking a strong thunderstorm over Douglas, moving northeast at 10 mph. Winds in excess of 40 mph will be possible with this storm. Locations impacted include... Douglas, Bisbee-Douglas Airport and Pirtleville. 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. 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 3156 10983 3146 10937 3133 10944 3134 10982 TIME...MOT...LOC 1908Z 224DEG 9KT 3133 10958 GL
Special Weather Statement National Weather Service Tucson AZ 115 PM MST Wed Jul 31 2019 AZZ506-514-312100- Santa Catalina and Rincon Mountains including Mount Lemmon/Summerhaven-Southeast Pinal County including Kearny/Mammoth/Oracle- 115 PM MST Wed Jul 31 2019 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN PINAL COUNTY UNTIL 200 PM MST... At 115 PM MST, Doppler radar was tracking a strong thunderstorm over Oracle, moving north at 10 mph. Winds in excess of 40 mph will be possible with this storm. Locations impacted include... Oracle, Mammoth, Saddlebrooke, San Manuel, Campo Bonito, Oracle Junction and Biosphere 2. 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. 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 3252 11061 3252 11095 3275 11086 3276 11053 TIME...MOT...LOC 2015Z 199DEG 7KT 3258 11078 GL
Special Weather Statement National Weather Service Tucson AZ 220 PM MST Wed Jul 31 2019 AZZ504-507-513-312200- Upper San Pedro River Valley including Sierra Vista/Benson-Dragoon/Mule/Huachuca and Santa Rita Mountains including Bisbee/Canelo Hills/Madera Canyon-Tucson Metro Area including Tucson/Green Valley/Marana/Vail- 220 PM MST Wed Jul 31 2019 ...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL PIMA COUNTY UNTIL 300 PM MST... At 220 PM MST, Doppler radar was tracking a strong thunderstorm near Corona De Tucson, or 13 miles east of Sahuarita, moving north at 10 mph. Winds in excess of 40 mph will be possible with this storm. Locations impacted include... Tucson, Vail, East Sahuarita, Corona De Tucson, Saguaro National Park East and Rita Ranch. 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 3177 11057 3176 11090 3213 11088 3214 11062 TIME...MOT...LOC 2120Z 165DEG 8KT 3194 11072 GL
Special Weather Statement National Weather Service Tucson AZ 244 PM MST Wed Jul 31 2019 AZZ502>504-312215- Tohono O'odham Nation including Sells-Upper Santa Cruz River and Altar Valleys including Nogales-Tucson Metro Area including Tucson/Green Valley/Marana/Vail- 244 PM MST Wed Jul 31 2019 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN PIMA COUNTY UNTIL 315 PM MST... At 241 PM MST, Doppler radar was tracking a cluster of strong thunderstorms approaching portions of the Greater Tucson area. These storms were moving north at 5 to 10 mph. Winds in excess of 40 mph will be possible with these storms along with heavy downpours and small hail. Locations impacted include... Tucson, Flowing Wells, South Tucson, Three Points, Tucson Estates, Saguaro National Park West, Valencia West, Tucson International Airport, San Xavier Mission and Ryan AirField. 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 3198 11089 3197 11144 3235 11132 3233 11088 TIME...MOT...LOC 2141Z 190DEG 5KT 3207 11099
The Phoenix radar (KIWA), 151 km away, was scanning. The volume nearest the first event began at 21:54 UTC.
2 flash flood, 1 heavy rain, 1 lightning. Local standard time, as filed.
About 2.5 inches of rainfall in less than two hours caused the roof of a historic building to collapse in Ajo. Residents of the building, which used to be the Curley School, were displaced.
Lightning struck an orthodontist office in Tucson near Pima and Alvernon causing damage to some computer equipment in the office.
About 2.5 inches of rain caused flash flooding on the east side of Tucson. The intersection of 22nd and Kolb as well as the intersection of Irvington and Pantano had over a foot water running through them. Numerous vehicles were stranded in the flood waters and several water rescues were performed in the area. An 11-year old child was rescued after falling into a swift flowing Alamo Wash near Bellevue St.
Heavy rainfall of 2.5 inches caused flash flooding in Ajo with water over 1 foot deep flowing across many streets.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2019Every state in 2019This day in weather historyWarnings in Arizona, July 2019
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: 843838, 848078, 843834, 847613.