Isolated thunderstorms moved northwest across southeast Arizona during the afternoon and evening. Thunderstorm winds downed numerous trees in Oro Valley.
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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 thunderstorms moved northwest across southeast Arizona during the afternoon and evening. Thunderstorm winds downed numerous trees in Oro Valley. In Sierra Vista, heavy rain caused a roof to collapse in a commercial building and lightning sparked a fire at a nearby apartment complex.
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 Aug 16, 2:00 PM MST, 3 hours 10 minutes earlier.
Area Forecast Discussion National Weather Service Tucson AZ 200 PM MST Wed Aug 16 2023 .SYNOPSIS...Scattered afternoon showers and thunderstorms will affect parts of southeast Arizona through Friday with above normal temperatures. Moisture flowing northward ahead of tropical system Hilary is expected to enhance rain chances over much of western Arizona late Saturday into Saturday night, mainly west of Tucson. && .DISCUSSION...Correction to correct authors. A few thunderstorms have popped up over the western half of the area as expected today as drier air has invaded the far eastern part of the forecast area. Not to say there won't be any storms east, just rather isolated. Like yesterday activity should settle fairly quickly after sunset. Temperatures are running 3-6 degrees warmer than 24 hours ago with another, slightly warmer day expected tomorrow. And speaking of tomorrow, convection wise again expecting scattered showers and thunderstorms much like today except likely forming first eastern areas and heading west from there. Similar intensities as well, generally garden variety with a couple that get frisky. Friday is a bit of a challenge as we will have moisture around on a southeast flow with the upper high having less of a suppressive influence. So we may be looking at a fairly active day, primarily central and western parts of the forecast area which includes the Tucson metro. Potential for a few more frisky storms that day given it should be a better environment and we may need to watch for a few problem rainers. I have adjusted the given blend pops downward for most periods including Friday as they continue the trend of being too robust. Then attention turns to the weekend and what impact tropical system Hilary will have on the area. Based on the latest guidance it will remain well to our west with no direct impacts from the storm itself. What we will need to watch is the moisture streaming northward up the gulf to the east of the storm itself. This moisture looks to arrive in earnest Saturday afternoon into Saturday night bringing an enhancement to the convection as well as allowing the storms to be more efficient rain producers. The problem during this time period is there will be a sharp gradient in the precipitation between a fair amount west and nearly none east and at this time that boundary looks to bisect our area north/south in the vicinity of Tucson. The expectation at this time is likely for little to no precipitation well to the east (think Willcox eastward), with more widespread showers and thunderstorms well to the west (think TO Nation westward) with potential for some flooding, with a fairly sharp boundary somewhere in the middle (think Tucson). The problem is where that boundary will be and that will depend on the storm track as well as the position of the upper high and is subject to change at this point. For now, I have made some fairly significant tweaks to the given pop blend by trimming pops Tucson eastward with more significant trimming the further east you go. Also added a couple of degrees to the Saturday afternoon high temperature for the eastern third of the area. Sunday/Sunday night some form of Hilary will be moving north toward southern California with some moisture lingering over the area but we won't be in the best position dynamically to force convection so at this time would think scattered showers and thunderstorms would cover it for central and eastern areas (<50%) and convection likely western Pima county. Monday and Tuesday, behind this system we will likely be in a low grade type of pattern with the potential to ramp up a bit mid week. && .AVIATION...valid through 18/00z. ISOLD-SCT SHRA/TSRA with bases SCT-BKN 8-14k ft AGL thru 17/05Z and again after 17/20Z thru the end of the period. SFC winds WLY-NWLY up to 15 kts thru 17/06Z and agaiGiralten after 17/20Z thru the end of the period. Erratic wind gusts of 35-45 kts in TSRA. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Some scattered shower and thunderstorm activity Thursday, then increasing Friday into the weekend. Any storms that do form will be capable of producing strong, erratic, and gusty outflows. Outside of thunderstorm winds, 20-foot winds will be west- northwesterly of speeds 10-20 mph each afternoon through the rest of the week. Daytime temperatures will be well above average through Thursday. Minimum RH in the lower elevations will generally range from 15-25% and 25-40% in the higher elevations, increasing Friday into the weekend. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && Public...Cerniglia Aviation...Tetrault Fire Weather....Tetrault Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Special Weather Statement
National Weather Service Tucson AZ
316 PM MST Wed Aug 16 2023
AZZ501-502-162300-
Western Pima County Including Ajo/Organ Pipe Cactus National
Monument-Tohono O'odham Nation including Sells-
316 PM MST Wed Aug 16 2023
...A strong thunderstorm will impact portions of northwestern Pima
County through 400 PM MST...
At 316 PM MST, Doppler radar was tracking a strong thunderstorm near
Ajo, moving northwest at 5 mph.
HAZARD...Winds in excess of 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Ajo and Why.
This includes the following highways...
Route 85 between mile markers 34 and 54.
Route 86 between mile markers 53 and 54.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3241 11308 3251 11283 3251 11277 3228 11267
3218 11290
TIME...MOT...LOC 2216Z 156DEG 5KT 3231 11283
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
AWHSpecial Weather Statement
National Weather Service Tucson AZ
359 PM MST Wed Aug 16 2023
AZZ501-162345-
Western Pima County Including Ajo/Organ Pipe Cactus National
Monument-
359 PM MST Wed Aug 16 2023
...A strong thunderstorm will impact portions of northwestern Pima
County through 445 PM MST...
At 359 PM MST, Doppler radar was tracking a strong thunderstorm near
Ajo. This storm was nearly stationary.
HAZARD...Wind gusts up to 50 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Ajo.
This includes Route 85 between mile markers 33 and 45.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3251 11308 3250 11281 3236 11278 3228 11297
3249 11314
TIME...MOT...LOC 2259Z 156DEG 4KT 3240 11291
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH
AWHThe Tucson radar (KEMX), 52 km away, was scanning. The volume nearest the first event began at 00:08 UTC.
1 lightning, 1 heavy rain, 1 thunderstorm wind. Local standard time, as filed.
Lightning struck the roof of the Canyon Vista Homes apartment complex. The fire smoldered for several hours until rainfall evaporated, then spread through six apartments, causing extensive smoke damage and displacing six tenants.
Heavy rain of 1 inch in 30 minutes overwhelmed the roof drain of the Burger King, causing extensive ceiling damage to the interior and closure of the restaurant that persisted for several weeks.
Thunderstorm winds downed multiple trees in Oro Valley in an area generally bounded by Tangerine and 1st Avenue on the northeast to La Canada and Lambert Rd. Solar panels were damaged at Naranja Park and several Town Hall buildings sustained damage to roof tiles. Four windows and two sliding glass doors were blown out at one home.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2023Every state in 2023This day in weather historyWarnings in Arizona, August 2023
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: 1129603, 1129604, 1129602.