Thunderstorms with heavy rain produced flash flooding north of Interstate 40 to the Four Corners.
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.
Thunderstorms with heavy rain produced flash flooding north of Interstate 40 to the Four Corners.
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 11, 9:00 AM MST, 7 hours earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 900 AM MST TUE AUG 11 2015 .SYNOPSIS...DEEP MOISTURE WILL REMAIN IN PLACE ACROSS NORTHERN ARIZONA THROUGH WEDNESDAY WITH FAIRLY WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY EXPECTED. A DECREASE IN MONSOON ACTIVITY IS FORECAST FROM THURSDAY AND INTO EARLY NEXT WEEK AS THE SUBTROPICAL HIGH MOVES OVER ARIZONA BRINGING MORE STABLE AIR ALOFT AND A REDUCTION IN STORM COVERAGE. && .DISCUSSION... WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS DEEP MOISTURE REMAINS ENTRENCHED ACROSS NORTHERN ARIZONA. THE STRONGER STORMS TODAY WILL BE CAPABLE OF PRODUCING POTENTIALLY SEVERE HAIL AND LOCALIZED FLOODING...WITH SOUTH TO NORTH TRAINING THUNDERSTORMS POSSIBLE. SIGNIFICANT MOISTURE HANGS ON THROUGH WEDNESDAY WITH ANOTHER ROUND OF NUMEROUS SHOWERS ANTICIPATED. THURSDAY THROUGH SUNDAY...THE HIGH GRADUALLY SHIFTS WESTWARD APPROACHING AND EVENTUALLY MOVING INTO ARIZONA. WHILE A REDUCTION IN STORMS IS EXPECTED...ENOUGH MOISTURE AND INSTABILITY WILL REMAIN TO KEEP SLIGHT CHANCES FOR PRECIPITATION EACH DAY. && .AVIATION...FOR THE 18Z PACKAGE...EXPECT SCATTERED TO NUMEROUS SHRA/TSRA THROUGH 03Z WEDNESDAY. STORMS TODAY WILL GENERALLY BE MOVING FROM SOUTH TO NORTH AROUND 15 TO 20 KTS. LOCALIZED MVFR/IFR CONDITIONS IN REDUCED VISIBILITY AND CEILINGS ARE POSSIBLE UNDER THE STRONGEST STORMS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...MCCOLLUM/KD AVIATION...RR/TC FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT WEATHER.GOV/FLAGSTAFF
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 323 PM MST TUE AUG 11 2015 AZZ004>018-037>040-120715- 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- 323 PM MST TUE AUG 11 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR APACHE...COCONINO... NORTHERN GILA...NAVAJO...AND YAVAPAI COUNTIES IN NORTHERN ARIZONA. .DAY ONE...THIS AFTERNOON AND TONIGHT WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED...MAINLY NORTH OF INTERSTATE-40...AS DEEP MOISTURE REMAINS ENTRENCHED ACROSS NORTHERN ARIZONA. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS TO 55 MPH...PENNY SIZED HAIL AND LOCALIZED FLASH FLOODING...WITH SOUTH TO NORTH MOVEMENT OF THUNDERSTORMS. STORM ACTIVITY WILL DIMINISH AFTER SUNSET. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY SIGNIFICANT MOISTURE HANGS ON OVER NORTHWEST ARIZONA THROUGH WEDNESDAY WITH ANOTHER ROUND OF NUMEROUS SHOWERS ANTICIPATED ALONG AND WEST OF A PRESCOTT...FLAGSTAFF...PAGE LINE. DRYING IS EXPECTED FURTHER EAST. THURSDAY THROUGH MONDAY...THE HIGH GRADUALLY SHIFTS WESTWARD APPROACHING AND EVENTUALLY MOVING INTO ARIZONA. WHILE A REDUCTION IN STORMS IS EXPECTED...ENOUGH MOISTURE AND INSTABILITY WILL REMAIN TO KEEP SLIGHT CHANCES FOR PRECIPITATION EACH DAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
248 PM MST TUE AUG 11 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1000 AM TSTM WND DMG 4 N PRESCOTT VALLEY 34.67N 112.32W
08/11/2015 YAVAPAI AZ EMERGENCY MNGR
A 12 IN. DIAMETER TREE BLOWN OVER NEAR INTERSECTION OF
VIEWPOINT AND HORSESHOE IN PRESCOTT VALLEY. NUMEROUS
BRANCHES DOWN FROM OTHER NEARBY TREES.
&&
EVENT NUMBER FGZ1500114
NWS FLAGSTAFFPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
257 PM MST TUE AUG 11 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1201 PM TSTM WND GST COTTONWOOD 34.73N 112.02W
08/11/2015 M52 MPH YAVAPAI AZ TRAINED SPOTTER
RAINFALL 0.60 INCH
&&
EVENT NUMBER FGZ1500115
DGVPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
259 PM MST TUE AUG 11 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1204 PM TSTM WND DMG COTTONWOOD 34.73N 112.02W
08/11/2015 YAVAPAI AZ LAW ENFORCEMENT
HIGH WIND BLEW THROUGH CENTRAL PORTION OF CITY... TREES
DOWN... POWER LINES DOWN... LOTS OF LIGHTNING
&&
EVENT NUMBER FGZ1500116
DGVPRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
301 PM MST TUE AUG 11 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1000 AM TSTM WND DMG 4 N PRESCOTT VALLEY 34.67N 112.32W
08/11/2015 YAVAPAI AZ EMERGENCY MNGR
SEVERAL TREES DOWN ALONG ADDIS AVE. FROM VIEWPOINT TO
NEAR ROCKLAND DRIVE. TREES RANGED FROM 1-2 FEET IN
DIAMETER.
&&
CORRECTED REMARKS
EVENT NUMBER FGZ1500114
NWS FLAGSTAFFSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE FLAGSTAFF AZ 327 PM MST TUE AUG 11 2015 AZZ009-010-039-112300- NORTHEAST PLATEAUS AND MESAS HWY 264 NORTHWARD-CHINLE VALLEY-BLACK MESA AREA- 327 PM MST TUE AUG 11 2015 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN NAVAJO AND NORTHWESTERN APACHE COUNTIES UNTIL 400 PM MST... AT 326 PM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 11 MILES SOUTH OF CHILCHINBITO...OR 28 MILES NORTHWEST OF CHINLE... MOVING NORTHEAST AT 20 MPH. HALF INCH HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH THIS STORM. LOCATIONS IMPACTED INCLUDE... ROUGH ROCK. PRECAUTIONARY/PREPAREDNESS ACTIONS... HEAVY RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD TO FLOWING WATER IN NORMALLY DRY WASHES. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS. && LAT...LON 3625 10997 3633 11016 3671 10999 3659 10969 TIME...MOT...LOC 2226Z 206DEG 19KT 3636 11003 MAS
The Flagstaff radar (KFSX), 112 km away, was scanning. The volume nearest the first event began at 22:58 UTC.
4 flash flood. Local standard time, as filed.
Flash flooding washed out the majority of the dirt roads in the Dilkon, Tees Toh, Indian Wells, to White Cone area.
Heavy rain from thunderstorms caused flash flooding along Highway 160 between MP 361 and MP 379. The flooding stopped traffic.
Heavy rain produced flash flooding in Indian Route 59 at MP 22 and MP 33.
Water flooded the road near the junction of Highway 160 and State Route 98.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2015Every state in 2015This day in weather historyWarnings in Arizona, August 2015
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: 600111, 600114, 600116, 600118.