Deep monsoon moisture remained over northern Arizona which lead to strong thunderstorms 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 remained over northern Arizona which lead to strong thunderstorms 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 15, 2:49 AM MST, 4 hours 53 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 249 AM MST Mon Aug 15 2022 .SYNOPSIS...An active monsoon pattern will continue across northern and central Arizona through the upcoming week. Heavy rainfall leading to flash flooding will continue to remain a threat. && .DISCUSSION...An active monsoon pattern will continue through the next week across the forecast area. Showers and isolated thunderstorms continue to develop across western Yavapai county along the southern edge of a decaying MCV. Today looks to be like a fairly active day and with the very wet conditions in place due to the rain we have seen over the past week, flash flooding remains a big concern. PWATs remain around 1-1.25" and some of the hi-res guidance shows decent rainfall across parts of the area. However, the aforementioned decaying MCV has been crossing the region through the early morning hours and we have had considerable cloud cover across the state. This feature is pushing off towards the north-northwest but there is concern that the cloud cover will not erode early enough to allow for widespread convection to develop. Will we have enough energy to allow for convection after such an active day yesterday? Models show that instability will increase as we head into the afternoon with perhaps a later start time for storms than the past several days. So, we do expect storms to develop but just how widespread they will be is not as clear. With all that said, thoughts were given to having another Flash Flood Watch today. Uncertainty remains as to where the greatest threat lies and in the end, we opted to forgo the watch due to lower confidence and just continue to message the flash flood threat, which will exist for much of the week. As a reminder, be sure to avoid flood prone areas (recent burn scars, slot canyons, and low- water crossings). If you come across flooded roadways...turn around, don't drown. As we head into Tuesday and Wednesday, we may start to see a slightly less active monsoon across the desert southwest. This doesn't mean that we will be free of storms but just that there may be less coverage. Any storms that do develop will still have heavy rainfall and flash flooding will remain a concern. Things start to turn more active as we head into Thursday and through the weekend. A system will move from the Gulf of Mexico across northern Mexico and into Sonora over the next several days, which should start to bring more moisture into Arizona once again. Another uptick in convection is expected across the region with the flash flood threat continuing. && AVIATION...For the 12Z TAF package...Light to calm winds under scattered high clouds with a few isolated rain showers lingering this morning. Localized patchy fog and mist will be possible until just after sunrise. Showers and storms are forecast to begin by 19z over high terrain, becoming more widespread from 20Z through 03Z. VFR conditions through the day as surface winds remain light away from storms. Aviation discussion not updated for TAF amendments. && FIRE WEATHER...Widespread showers and storms in the afternoon today and Tuesday with some activity lasting into the evening. Expect gusty, erratic winds near thunderstorms. Flash flooding remains possible. Light winds with minimal fluctuation in the forecast. Wednesday through Friday...Monsoon moisture will remain in place with showers and thunderstorm each day. Slightly less coverage Wednesday before widespread activity returns to end the week. && && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...Meola AVIATION...JM FIRE WEATHER...JM For Northern Arizona weather information visit weather.gov/flagstaff
The Flagstaff radar (KFSX), 171 km away, was scanning. The volume nearest the first event began at 14:42 UTC.
6 flash flood. Local standard time, as filed.
Flooding was reported in farmland and along roads near the Moenkopi Wash near Tuba City. This wash flows west then south to the Little Colorado River.
Heavy rain over the Schultz Fire scar (2010) and Tunnel/Pipeline fire scar (2022) caused flash flooding. North Copeland Lane was overtopped with muddy water and debris 8 inches deep and 10 to 15 feet wide. There was also minor flooding of Henry Drive near Campbell Avenue.
Lower Antelope Canyon was close due to flash flooding. Water remained in the popular tourist attraction (sandstone slot canyon) through much of August 16 due to residual flood waters (large puddles).
Major flooding was reported north of Many Farms Lake.
Indian Route 15 from Burnside to Greasewood flooded in areas and there were puddles on the road. This is a paved road.
The river gauge on the Little Colorado River near Cameron showed a 3 foot rise between 715 PM and 1115 PM. The majority of this flow was likely from the Moenkopi Wash that had a flash flood the day before.
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: 1055027, 1055030, 1055154, 1055145, 1055031, 1055150.