Thunderstorms caused heavy rain, flash flooding, and debris along and over Interstate 17 between Black Canyon City and Sunset Point rest area. The interstate was closed for a while because of rock slides and multiple accidents.
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 caused heavy rain, flash flooding, and debris along and over Interstate 17 between Black Canyon City and Sunset Point rest area. The interstate was closed for a while because of rock slides and multiple accidents. Side roads were flooded underneath the interstate.
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 12, 3:30 PM MST, 4 hours 30 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 330 PM MST TUE AUG 12 2014 .SYNOPSIS...MONSOON MOISTURE WILL INCREASE THROUGH WEDNESDAY THUS EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE NORTHLAND. STARTING THURSDAY...SOUTHWESTERLY FLOW SHOULD BRING DRIER AIR INTO NORTHWEST ARIZONA...WITH DECREASING STORM CHANCES ACROSS THE KAIBAB PLATEAU. THE DRY AIR SPREADS EASTWARD ON FRIDAY AND THE WEEKEND IS CURRENTLY LOOKING DRY FOR ALL EXCEPT AREAS ALONG THE EASTERN MOGOLLON RIM WHERE A SLIGHT CHANCE OF AFTERNOON STORMS WILL CONTINUE. && .DISCUSSION...DEEPER TROPICAL MOISTURE HAS ARRIVED AS EXPECTED WITH SURFACE DEWPOINT TEMPERATURES UP BY 5 TO 10 DEGREES ACROSS NORTHERN ARIZONA AS COMPARED TO THIS TIME YESTERDAY. MODELS CONTINUE TO SHOW GOOD CHANCES FOR RAIN IN THE FORECAST THROUGH WEDNESDAY WITH A GRADUAL TAPER IN MOISTURE AND SHOWERS ON THURSDAY AND FRIDAY. TODAYS SATELLITE IMAGERY SHOWS EXTENSIVE CLOUD COVER FROM THE MEXICAN BORDER NORTHWARD INTO UTAH. THESE CLOUDS WILL TEND TO LIMIT SURFACE HEATING WHICH IS A NEEDED TRIGGER TO PRODUCE DEEPER CONVECTION. IN THE ABSENCE OF STRONG SURFACE HEATING WE TYPICALLY NEED SIGNIFICANT UPPER LEVEL FORCING FROM A DISTURBANCE ALOFT. TODAY WE HAVE NEITHER STRONG SURFACE HEATING NOR SIGNIFICANT FORCING ALOFT...WHICH MEANS WE WILL LIKELY HAVE LOWER THUNDERSTORM COVERAGE THAN THE DEEP MOISTURE ALONE MIGHT SUGGEST. THEREFORE WE ARE FORECASTING WIDESPREAD RAIN SHOWERS WITH SEVERAL AREAS OF SCATTERED THUNDERSTORMS TODAY. SOME OF THESE SHOWERS TODAY AND TOMORROW MAY BE HEAVY AT TIMES WITH AN ELEVATED RISK FOR LOCAL FLASH FLOODING. HOWEVER THE FLASH FLOODING RISK IS NOT HIGH ENOUGH TO WARRANT A WATCH AT THIS TIME MAINLY DUE TO THE LACK OF A STRONG FORCING MECHANISM. BY WEDNESDAY A TROUGH MOVING THROUGH ARIZONA MAY CHANGE THE PICTURE AND BRING THE UPPER LEVEL FORCING NEEDED FOR DEEPER CONVECTIVE STORM ACTIVITY. THURSDAY AND FRIDAY...WE START TO TRANSITION TO A DRIER WEATHER PATTERN AS A TROUGH MOVING THROUGH THE WEST BEGINS TO BRING DRIER SOUTHWESTERLY WINDS REPLACING THE DEEPER MOISTURE. GOOD CHANCES FOR THUNDERSTORMS CONTINUE WITH THE HIGHEST CHANCES OVER THE MOUNTAIN REGIONS. SATURDAY AND SUNDAY...LONG RANGE MODELS CONTINUE TO SHOW A SHARP DOWNWARD TREND IN STORM ACTIVITY AS A MID-LATITUDE TROUGH PINS THE SUBTROPICAL RIDGE TO THE SOUTH ALONG THE MEXICAN BORDER. THE WEST TO EAST ORIENTATION OF THE RIDGE AXIS WILL EFFECTIVELY BLOCK ANY MOISTURE TRANSPORT FROM THE TROPICS AND INSTEAD BRING IN SIGNIFICANTLY DRIER AIR IN FROM THE PACIFIC. EXPECT MUCH LOWER CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND. && .AVIATION...FOR THE 00Z PACKAGE...EXPECT WDSPRD SHRA/TSRA THROUGH THE FORECAST PERIOD. SCT/ISOLD MVFR/IFR CONDITIONS IN TSRA POSSIBLE TONIGHT AND WEDNESDAY...WITH MVFR CIGS LASTING THROUGH THE MORNING HOURS OVER HIGHER TERRAIN. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC.........BOHLIN AVIATION.......RR FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT WEATHER.GOV/FLAGSTAFF
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 351 PM MST TUE AUG 12 2014 AZZ004>018-037>040-130700- 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- 351 PM MST TUE AUG 12 2014 THIS HAZARDOUS WEATHER OUTLOOK IS FOR APACHE...COCONINO... NORTHERN GILA...NAVAJO...AND YAVAPAI COUNTIES IN NORTHERN ARIZONA. .DAY ONE...THIS AFTERNOON AND TONIGHT WIDESPREAD SHOWER AND THUNDERSTORM COVERAGE WILL CONTINUE ACROSS NORTHERN ARIZONA IN THE OVERNIGHT HOURS IN DEEP MONSOONAL MOISTURE. STORM MOTION WILL GENERALLY BE FROM SOUTH TO NORTH. LOCALLY HEAVY PRECIP AMOUNTS ARE POSSIBLE WITH AN ELEVATED RISK FOR FLASH FLOODING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY ON WEDNESDAY...DEEP TROPICAL MOISTURE AND SOUTHERLY FLOW WILL KEEP WIDESPREAD RAINFALL AND THUNDERSTORMS DEVELOPING ACROSS THE AREA. THERE WILL BE AN ELEVATED RISK FOR FLASH FLOODING. THURSDAY ONWARD...DRIER WILL GRADUALLY MOVE INTO ARIZONA FROM THE WEST SLOWLY DECREASING STORM CHANCES EACH DAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. RB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE FLAGSTAFF AZ 527 PM MST TUE AUG 12 2014 AZZ008-037-130115- YAVAPAI AZ- 527 PM MST TUE AUG 12 2014 THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... CENTRAL YAVAPAI COUNTY IN WEST CENTRAL ARIZONA UNTIL 615 PM MST AT 524 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED STRONG THUNDERSTORMS MOVING THROUGH SOUTHWESTERN YAVAPAI COUNTY FROM NEAR BAGDAD TO WAGONER. THESE STORMS ARE NEARLY STATIONARY. HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THE STRONGER STORMS...ALONG WITH LOCALLY VERY HEAVY RAINFALL. HEAVY RAIN WILL CAUSE CREEKS...STREAMS...AND WASHES IN THE AREA TO RISE. PRECAUTIONARY/PREPAREDNESS ACTIONS... IF YOU ARE IN THE ADVISORY AREA AND STORMS APPROACH...TAKE SHELTER IN A STURDY BUILDING. && LAT...LON 3448 11329 3470 11314 3427 11223 3406 11239 TIME...MOT...LOC 0025Z 180DEG 0KT 3444 11283 MCS
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
623 PM MST TUE AUG 12 2014
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 PM HEAVY RAIN 1 SSE MILEPOST 285 ON S 34.56N 112.27W
08/12/2014 M1.80 INCH YAVAPAI AZ TRAINED SPOTTER
MEASURED 1.8 INCHES OF RAIN IN ONE HOUR...STILL
RAINING.
&&
EVENT NUMBER FGZ1400057
CLMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
756 PM MST TUE AUG 12 2014
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 PM FLASH FLOOD YAVA 34.47N 112.89W
08/12/2014 YAVAPAI AZ LAW ENFORCEMENT
COUNTY ROAD 15 WASHED OUT MILEPOST MARKER 26 NEAR YAVA
&&
EVENT NUMBER FGZ1400058
DMThe Flagstaff radar (KFSX), 96 km away, was scanning. The volume nearest the first event began at 03:01 UTC.
1 heavy rain, 1 flash flood. Local standard time, as filed.
Heavy rain fell along Interstate 17 between the Sunset Point Rest Area and Black Canyon City.
Thunderstorms produced heavy rain and flash flooding along Interstate 17 between Sunset Point Rest Area and Black Canyon City.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2014Every state in 2014This day in weather historyWarnings in Arizona, August 2014
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: 541440, 541441.