Deep moisture remained over northern Arizona. Most of the forcing from an inverted trough that moved across the state had moved northward which lead to fewer storms.
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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 moisture remained over northern Arizona. Most of the forcing from an inverted trough that moved across the state had moved northward which lead to fewer storms.
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 25, 10:31 AM MST, 4 hours 29 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 1031 AM MST Tue Jul 25 2017 .SYNOPSIS...Another round of scattered thunderstorms will develop today, some with heavy rainfall. A decrease in storm coverage is anticipated starting Wednesday, especially across western and central Arizona. More typical monsoon conditions are expected to return late in the week. && .UPDATE... A weakening thunderstorm complex now over Mohave county is moving eastward into Coconino county. Precipitation chances this afternoon were raised to near 100% for areas west and north of a line from Page-Tuba City-Seligman, with the idea there will be steady moderate rainfall and a few embedded tstorms. Our morning sounding has above normal amounts of preciptable water, however the winds aloft below 15 kft msl are SW and this should keep large amount of upslope cloud cover going across western AZ, limiting heating and storm strength. Scattered storms are expected across northeast AZ through this evening. && .PREV DISCUSSION /438 AM MST/...Deep monsoon moisture remains over northern and central Arizona this morning. Dewpoints are about as high as they get for our area, around 60 in the mountains and mid 60s to low 70s for lower elevations. With the very high humidity, some areas of low clouds and fog have developed and will continue until an hour or two after sunrise. The main inverted trough that moved across the state yesterday is shifting northward and will be mostly out of the picture by this afternoon. The most concentrated area of showers and thunderstorms this morning is over far NW Arizona and SW Utah in the vicinity of the exiting disturbance. For later today, we are seeing some drying and warming of the mid and upper levels. This should allow for better surface heating and instability than we saw yesterday, but could be partially offset by the warming mid levels. Most mesoscale models have been suggesting the northern half of Yavapai and much of Coconino County as the most active areas today, with less activity elsewhere. With deep moisture still in place, there will be a threat of localized heavy downpours and flooding. Activity should decrease by mid evening and be mostly over with by tonight. Wednesday through Thursday - drier and more stable air is forecast to move over central and western Arizona, leading to decrease in storm coverage. Moisture lingers along the AZ/NM border with scattered storms. Friday into the weekend - high pressure centered near the four corners will result in a gradually moistening east to southeast flow for northern Arizona. Models also hinting at another inverted trough passing through which could enhance storm activity. A return to more typical monsoon storm coverage is in our forecast. && .AVIATION...For the 18Z package...Periods of rain showers and thunderstorms will develop through the afternoon most numerous west of a KPRC-KFLG-KPGA line. MVFR/IFR conditions are likely in the stronger storms. Activity will mostly end by 06Z with VFR conditions spreading across northern Arizona. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Typical late morning to early evening thunderstorms are expected today. On Wednesday, the chances for showers and thunderstorms will continue, but coverage and frequency should decrease. Thursday through Saturday...For Thursday and Friday the coverage and frequency of showers and storms are expected to remain on the low side. Slightly drier and warmer conditions near the surface will enhance the threat for gusty outflow winds. On Saturday, a renewed push of moisture may return active monsoon conditions to the fire district. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...DL/JJ AVIATION...McCollum FIRE WEATHER...KD For Northern Arizona weather information visit weather.gov/flagstaff
Hazardous Weather Outlook National Weather Service Flagstaff AZ 407 AM MST Tue Jul 25 2017 AZZ004>018-037>040-260200- Kaibab Plateau-Marble and Glen Canyons-Grand Canyon Country- Coconino Plateau-Yavapai County Mountains- Northeast Plateaus and Mesas Hwy 264 Northward-Chinle Valley- Chuska Mountains and Defiance Plateau- Little Colorado River Valley in Coconino County- Little Colorado River Valley in Navajo County- Little Colorado River Valley in Apache County- Western Mogollon Rim-Eastern Mogollon Rim-White Mountains- Northern Gila County-Yavapai County Valleys and Basins- Oak Creek and Sycamore Canyons-Black Mesa Area- Northeast Plateaus and Mesas South of Hwy 264- 407 AM MST Tue Jul 25 2017 This hazardous weather outlook is for Apache...Coconino... Northern Gila...Navajo...and Yavapai Counties in Northern Arizona. .DAY ONE...Today and Tonight Deep monsoon moisture will remain over northern Arizona today. Expect another round of scattered showers and thunderstorms into early evening, with the highest chances over Coconino and Yavapai Counties. A few of the storms could produce heavy rainfall and localized flooding. .DAYS TWO THROUGH SEVEN...Wednesday through Monday A decrease in storm coverage is expected Wednesday and Thursday before ramping back up by Friday and the Weekend. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures.
The Cedar City radar (KICX), 138 km away, was scanning. The volume nearest the first event began at 21:59 UTC.
1 flash flood. Local standard time, as filed.
Heavy rain over Utah caused flash flooding in Paria Canyon that flowed into Arizona. The River gauge on the Paria River (just before the confluence with the Colorado River near Lees Ferry) showed at 2 foot rise (6.16 foot stage).
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2017Every state in 2017This day in weather historyWarnings in Arizona, July 2017
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: 719004.