Abundant monsoon moisture remained over northern Arizona with scattered thunderstorms producing heavy rain.
Every event with a place to put it. Tap one for its entry below.
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.
Abundant monsoon moisture remained over northern Arizona with scattered thunderstorms producing heavy rain.
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 Jul 29, 9:27 AM MST, 5 hours 33 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 927 AM MST Thu Jul 29 2021 .SYNOPSIS...Plentiful monsoonal moisture will persist over northern Arizona through the weekend. The greatest thunderstorm coverage is expected today and Friday, with storms capable of producing high rain rates and flash flooding. && .UPDATE...The scattered shower activity across western Coconino and northern Yavapai counties from earlier this morning has diminished leaving some leftover mid-level clouds. With the remainder of northern Arizona clear to scattered in cloud coverage as of now, expect sufficient diurnal heating to take place. This coupled with an abundant amount of monsoonal moisture should result in widespread thunderstorm coverage for today. Anticipate cumulus buildups forming now across the higher terrain transitioning into thunderstorms by 11am - 12pm MST. Coverage increases throughout the day continuing into the evening hours with flash flooding being the main threat. Showers and thunderstorms could continue overnight for areas mainly west of I-17 & Hwy 89. Most activity tapers after midnight. && .PREV DISCUSSION /321 AM MST/...Showers and thunderstorms have already begun to move across the region this morning as seen on radar. This has started over the White Mountains, Mogollon Rim and the higher elevations of north-central Arizona. This activity will build throughout the day with showers and thunderstorms moving into the lower elevations through the afternoon and evening hours. Activity looks to persist into the nighttime hours. Friday through Sunday looks to be the most widespread activity for the week. The risk of flash flooding continues through this timeframe due to soil moisture content and storms capable of producing high rain rates. Beginning Monday, monsoonal activity looks to decrease, similar to last week. Differences in models have this solution not completely sold just yet, however, there is a chance that high pressure moves overhead which will limit thunderstorm activity and increase temperatures. This is not a guarantee and updates to the forecast in the coming days will help us to hone in on a solution. && .AVIATION...For the 18Z package...Mainly VFR conditions expected. Thunderstorm activity develops after 18Z with brief periods of MVFR conditions and gusty and erratic winds in and around thunderstorms. Scattered shower and thunderstorm coverage is then expected to decrease after 06Z Friday. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered to widespread thunderstorm coverage is expected both today and Friday with flash flooding and lightning being the primary hazards. Light winds are expected outside of thunderstorm activity. Saturday through Monday...Scattered storms are forecast Saturday and Sunday. Storm coverage and rainfall intensity may begin to decrease on Monday. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...LaGuardia/Kobold AVIATION...LaGuardia FIRE WEATHER...Kobold For Northern Arizona weather information visit weather.gov/flagstaff
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1242 PM MST THU JUL 29 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1238 PM HAIL 1 WSW PARKS 35.26N 111.96W
07/29/2021 E0.75 INCH COCONINO AZ TRAINED SPOTTER
&&
TMThe Flagstaff radar (KFSX), 170 km away, was scanning. The volume nearest the first event began at 21:59 UTC.
4 flash flood, 1 flood, 1 heavy rain. Local standard time, as filed.
There was a 9.7 foot rise on the Moenkopi River gauge near Tuba City starting at 1500 on 7/29/21 and peaking at 0445 on 7/30/21.
The Chapter House in the community of Cornfields reported flash flooding in five areas along Indian Route 15 between the communities of Greasewood and Burnside, including near the community of Cornfields. The road was covered with more than two feet of water, heavy debris, and thick mud.
State Highway 60 was close due to flooding about 14 air miles south of Cibecue.
Four feet of water was flowing through Poquito Wash. Flooding was also reported in near buy near-by homes in north Prescott Valley.
About two inches of rain fell between 1810 and 1854 near the community of Parks. Rain gauge measured 3.31 inches of total rain during the day.
Local Law Enforcement reported that the flash flooding left large rocks, trees, bushes, and debris on area roads. Public works was called out to clean up the mess.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2021Every state in 2021This day in weather historyWarnings in Arizona, July 2021
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: 979834, 979836, 979896, 979908, 979833, 979935.