Thunderstorms developed and moved slowly east across Cochise and Graham counties during the afternoon. Thunderstorms produced large hail in Sierra Vista and south of Safford.
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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.
Thunderstorms developed and moved slowly east across Cochise and Graham counties during the afternoon. Thunderstorms produced large hail in Sierra Vista and south of Safford.
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 7, 9:21 AM MST, 3 hours 44 minutes earlier.
Area Forecast Discussion National Weather Service Tucson AZ 921 AM MST Mon Aug 7 2023 .SYNOPSIS...Somewhat more typical monsoon weather is expected this week with temperatures running closer to normal with scattered afternoon and evening thunderstorms across much of southeast Arizona. && .DISCUSSION...The 12z 500 mb chart placed the center of a strong high over the Texas Big Bend with southwest flow aloft over the area. Mid-level temperatures have also cooled in the past 24 hours, to -4 to -5 C versus -2C. PW values are significantly higher versus 24 hours ago also with values mostly ranging from 1" to 1.6" with localized areas up to 1.8". 16z infrared satellite imagery showed partly to mostly cloudy conditions across eastern half of the forecast areas with radar showing a few light showers or virga. Today will be a bit more active with localized severe storms and heavy rainers this afternoon and evening, mostly east of a Safford to Tucson to Nogales line with a focus on Cochise county. Latest HRRR hinting at outflows pushing north from evening Sororan storms keeping chance of elevated storms into the overnight hours. Oh, and this is nice to say. Highs today will be COOLER versus Sunday by 3 to 7 degrees depending on location, but still running several degrees above normal. && .AVIATION...Valid through 08/12Z. Afternoon -SHRA/-TSRA are possible for the whole forecast area. Sfc winds around -SHRA/TSRA are possible at producing FEW-SCT Clouds vAOA 10-15k and SCT-BKN AOA 20k AGL for areas south and east of Tucson thru 07/13Z and again from 08/0Z thru the end of the period. Otherwise SKC conditions. Sfc winds NW-WLY 10-15 kts gusting up to 25kts from 07/21Z thru 08/03Z, otherwise follow diurnal trends and generally remain under 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Daily rounds of showers and thunderstorms each afternoon through the weekend. Any storms that do form are capable of producing erratic and gusty outflows. Daytime temperatures remain a few degrees above normal before increasing next weekend. Minimum RH in the lower elevations range from 20-35% and 40-50% in the higher elevations today and decreasing to 10-20% and 20-30% by the weekend. && .CLIMATE...The consecutive day streak of highs 100 degrees or hotter in Tucson stands at 52 days. The probabilities each day this week of NOT hitting 100 degrees is less than 10%. && .PREV DISCUSSION...The upper level high that has dominated our weather with very hot temperatures continues to weaken a bit and drift east. The southerly flow that developed over the area continues to advect moisture into Arizona with PWs on the rise. The result of these changes will be cooler, closer to normal, temperatures and scattered afternoon and evening showers and thunderstorms through the work week. As is typical in this scenario, the convective potential each day will partly depend on the previous day/evenings convection. Next weekend an upper low is forecast to develop just off the California coast and will play a roll in the amount of storm coverage we will have. If the flow overhead becoming more southwesterly then there will be gradual drying and a decrease in storm coverage. Then the early part of the following week we could see a more pronounced warming and drying trend once again. Plenty of time to see how that may or may not unfold. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
The Tucson radar (KEMX), 56 km away, was scanning. The volume nearest the first event began at 20:06 UTC.
2 hail. Local standard time, as filed.
Several reports of quarter to golf ball size hail were received from Sierra Vista.
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: 1129598, 1129599.