Heavy rain caused debris to flow across Interstate 17 south of Sunset Rest Area. The road was closed after the debris punctured tires on several vehicles.
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.
Heavy rain caused debris to flow across Interstate 17 south of Sunset Rest Area. The road was closed after the debris punctured tires on several vehicles.
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, 2:40 PM MST, 6 hours 8 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 240 PM MST SUN JUL 29 2012 .SYNOPSIS...MOIST SOUTHEASTERLY FLOW WILL KEEP NORTHERN ARIZONA IN A WET MONSOON PATTERN THROUGH THE FIRST HALF OF THE WEEK. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED EACH DAY...WITH A THREAT OF LOCALIZED FLOODING. && .DISCUSSION...DEEP MOISTURE PLUME IS SPREAD ACROSS AZ THIS AFTERNOON WITH SATELLITE PW ESTIMATES INDICATING NEAR TO OVER 1INCH PW ACROSS THE ENTIRE STATE WITH THE DEEPEST MOISTURE OF 1.5 TO 2.0 INCHES POOLED OVER SOUTHERN/CENTRAL AZ. SCATTERED SHOWERS AND STORMS HAVE DEVELOPED ACROSS THE NORTHLAND AND WILL CONTINUE THROUGH THE EVENING HOURS. AN INVERTED TROUGH IS CENTERED JUST SOUTH OF THE SOUTH-CENTRAL AZ BORDER THIS AFTERNOON HELPING TO FUEL THUNDERSTORMS OVER FAR SOUTHERN AZ. THIS TROUGH FEATURE WILL ROTATE NORTH/NORTHWEST TONIGHT THROUGH MONDAY BRINGING THE FOCUS OF THUNDERSTORM ACTIVITY TO THE WESTERN HALF OF THE STATE. BY EARLY MONDAY...GFS ENSEMBLE MEANS SHOW PW OVER WESTERN PORTIONS OF OUR FORECAST AREA OF 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL. THIS ADDITIONAL MOISTURE AND POSSIBLE LIFT AHEAD OF THE TROUGH MAY KEEP SHOWERS GOING OVERNIGHT INTO MONDAY MORNING ACROSS PRIMARILY YAVAPAI AND COCONINO COUNTIES AND HAVE INCREASED PRECIPITATION CHANCES THERE. THE FOCUS FOR STORM ACTIVITY WILL CONTINUE TO BE COCONINO/YAVAPAI COUNTIES MONDAY WHERE THE DEEPEST MOISTURE WILL PRESIDE...WITH SCATTERED ACTIVITY ELSEWHERE. STORM MOTION WILL CONTINUE TO BE TO THE NORTH/NORTHWEST AT 10-15 MPH WITH HEAVY RAIN THE MOST LIKELY THREAT. LOCALIZED FLOODING WILL REMAIN A CONCERN...ESPECIALLY FOR AREAS THAT HAVE SEEN SIGNIFICANT RAINFALL OVER THE PAST COUPLE OF DAYS. A PIECE OF THE INVERTED TROUGH MEANDERS AROUND SOUTHERN CA THROUGH TUESDAY WHILE A MOIST SOUTHEASTERLY FLOW CONTINUES DAILY THUNDERSTORM ACTIVITY OVER NORTHERN AZ. FROM WEDNESDAY ONWARD...HIGH PRESSURE OVER THE CENTRAL PLAINS SLOWLY BUILDS WESTWARD. THIS SHOULD KEEP A MOIST SOUTH/SOUTHEAST FLOW ACROSS AZ WITH A CHANCE FOR THUNDERSTORMS EACH DAY. MOISTURE LEVELS ARE FORECAST TO BE LOWER THAN WHAT WE ARE CURRENTLY SEEING...SO DAILY STORM CHANCES REFLECT A MORE TYPICAL MONSOON PATTERN. && .AVIATION...FOR THE 00Z PACKAGE...EXPECT ISOLATED SHOWERS AND THUNDERSTORMS NORTH OF KGCN-KLFG-KSOW LINE. SOUTH OF THIS LINE...SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY DIMINISH AFTER 03Z BECOMING MAINLY ISOLATED AFTER 08Z. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED MONDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC.........MCS AVIATION.......MCCOLLUM FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT WEATHER.GOV/FLAGSTAFF
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 330 AM MST SUN JUL 29 2012 AZZ004>018-037>040-300700- 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- 330 AM MST SUN JUL 29 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL ARIZONA...NORTH CENTRAL ARIZONA...NORTHEAST ARIZONA AND WEST CENTRAL ARIZONA. .DAY ONE...TODAY AND TONIGHT AND TONIGHT A VERY MOIST AIR MASS WILL AFFECT NORTHERN AND CENTRAL ARIZONA TODAY. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP BY LATE MORNING AND EARLY AFTERNOON...AND MOVE TOWARD THE NORTHWEST AROUND 10 MPH. THERE IS A RISK OF LOCALIZED FLOODING WITH THE STRONGER STORMS. IN ADDITION...A FEW STORMS MAY PRODUCE HAIL OVER ONE HALF INCH IN DIAMETER. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY DEEP MOISTURE COMBINED WITH A DISTURBANCE MOVING THROUGH WESTERN ARIZONA WILL BRING A RISK OF LOCALLY HEAVY RAINFALL AND FLOODING TO YAVAPAI AND COCONINO COUNTIES MONDAY AND TUESDAY. A CHANCE OF THUNDERSTORMS WILL CONTINUE FOR THE LATTER HALF OF THE WEEK... THOUGH THE RISK OF HEAVY RAINFALL WILL DECREASE. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The national radar mosaic for the moment the first event began.
1 heavy rain. Local standard time, as filed.
Heavy rain from a thunderstorm washed debris across Interstate 17. The water and debris were about four inches deep. The road was closed after several vehicles punctured tires on the debris. The road opened after the flow stopped and the roadway was cleared.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2012Every state in 2012This day in weather historyWarnings in Arizona, July 2012
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: 405622.