Deep monsoon moisture over northern Arizona brought thunderstorms with heavy rain and flash flooding.
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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 FGZ wrote it up.
Deep monsoon moisture over northern Arizona brought thunderstorms with heavy rain and flash flooding.
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 17, 9:46 AM MST, 2 hours 4 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 946 AM MST Wed Aug 17 2022 .SYNOPSIS...An active monsoon pattern will continue across northern and central Arizona through the remainder of the week. Heavy rainfall leading to flash flooding will continue to remain a threat, especially Thursday through Sunday. Cooler temperatures are expected through the weekend. && .UPDATE...An inverted trough currently over Chihuahua will continue to retrograde westward today. This feature should provide a little subsidence across eastern Arizona this afternoon, subduing afternoon convection over Navajo and Apache counties. However, mean northeasterly flow should allow thunderstorms to develop primarily over the western Mogollon Rim (Flagstaff to Heber-Overgaard), then advect into northern Gila and Yavapai Counties later this afternoon and evening. The latest SPC HREF 3-hr QPF has neighborhood probabilities of exceeding 1" of rainfall around 70 percent centered over Yavapai County later this afternoon. As a result, think flash flooding will be the primary threat over Yavapai County later this afternoon. Isolated flash flooding will be possible elsewhere. && .PREV DISCUSSION /236 AM MST/...Another day with scattered showers and thunderstorms across the region is expected today. While we won't be completely storm free, we will see less coverage of storms than we have seen the past week or so. This brief reduction in widespread storms will only last through today as we will see an uptick in activity starting Thursday and increasing across the region through the end of the week. Even with less coverage today, any storms that do develop will still have heavy rainfall and the potential for flash flooding will remain a concern. The monsoon will really start to pick up again on Thursday as moisture increases across the forecast area in response to a system moving across northern Mexico. This disturbance is bringing in some tropical moisture and with it we will see PWATs rise between 1.25"- 2" across the region. This influx of deep moisture will result in an increased potential for heavy rainfall resulting in flash flooding as we head through the weekend, starting Friday where parts of the forecast area have been moved into a moderate risk for excessive rainfall by the WPC. The best forcing and instability may be off to our south but some of the model guidance is indicating that we will see a very active day. Whether in slight or moderate, the risk is there for widespread 1-2" rainfall amounts which combined with our already wet antecedent conditions may lead to flash flooding. There remains some limiting factors as cloud cover and lingering convection will affect what areas may see the greatest impacts. As a reminder, be sure to avoid flood prone areas (recent burn scars, slot canyons, and low-water crossings) and never cross flooded roadways. With troughing across the region, temperatures are expected to be much cooler through Saturday and generally 10-15 degrees below normal for this time of year. The active monsoon looks to continue into early next week but with ridging situated across the area, we actually start to see some drying out of the atmosphere. We still expect some storms to develop each day but coverage may be more isolated to scattered storms versus the numerous storms we anticipate over the weekend. Temperatures will also start to rebound and rise back to near or just below normal through the start of the week. && .AVIATION...For the 18z TAF package...Primarily VFR conditions are expected outside of thunderstorms over the next 24 hours. Scattered showers and thunderstorms will develop from KGCN-KFLG around midday, then will move westward into KSEZ-KPRC later this afternoon/evening. Surface winds will generally be light away from storms. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered showers and thunderstorms will develop along the Mogollon Rim this afternoon, then move into Gila and Yavapai Counties later this afternoon and evening. An uptick in activity is expected Thursday. Gusty, erratic winds, and flash flooding will be likely. Friday through Sunday...Widespread shower and thunderstorm activity is expected Friday into the weekend. Risk of flash flooding will increase, especially on Friday. && && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...TM/Meola AVIATION...TM FIRE WEATHER...TM/ET For Northern Arizona weather information visit weather.gov/flagstaff
The Flagstaff radar (KFSX), 89 km away, was scanning. The volume nearest the first event began at 18:51 UTC.
5 flash flood. Local standard time, as filed.
Heavy rain over the Schultz Fire scar (2010) and the Tunnel/Pipeline Fire scar (2022) caused flooding over a driveway near Glodia Drive and Copland Lane. A large debris flow was also seen at the intersection of Campbell Avenue and Henry Drive.
The steam gauge on Agua Fria River near Cordes Junction showed a 3.47 foot rise.
A stream gauge on Dry Beaver Creek showed a 1.55 foot rise.
A stream gauge on the Wet Beaver Creek measured a 2.15 foot rise.
Heavy rain caused a 2.2 foot rise in Newman Canyon which flows into Upper Lake Mary.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2022Every state in 2022This day in weather historyWarnings in Arizona, August 2022
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: 1055209, 1055222, 1055237, 1055232, 1055241.