As the monsoon high shifted northward, moisture increased across all of southeast Arizona, resulting in widespread thunderstorms. Some of these thunderstorms produced damaging wind gusts.
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 TWC wrote it up.
As the monsoon high shifted northward, moisture increased across all of southeast Arizona, resulting in widespread thunderstorms. Some of these thunderstorms produced damaging wind gusts.
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 Tucson, AZ wrote its last area forecast discussion before the first event at Aug 8, 2:34 PM MST, 1 hour 43 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 234 PM MST WED AUG 8 2012 .SYNOPSIS...STRONG HIGH PRESSURE WILL BRING HOT TEMPERATURES THROUGH THE WEEKEND WITH NEAR RECORD HIGHS IN SOME LOCATIONS. ENOUGH MOISTURE WILL REMAIN IN PLACE TODAY FOR SCATTERED SHOWERS AND THUNDERSTORMS BY LATE AFTERNOON AND EVENING HOURS. THUNDERSTORMS WILL THEN GENERALLY BE CONFINED TO MAINLY HIGHER TERRAIN AREAS THURSDAY THROUGH SUNDAY BEFORE INCREASING AGAIN EARLY NEXT WEEK. && .DISCUSSION...STORMS ARE FIRING ON SCHEDULE ALONG THE RIM WITH A FEW CELLS POPPING UP ON THE SKY ISLANDS. STILL CONCERNED FOR A DECENT SEVERE WEATHER EVENT TODAY. MODIFIED MORNING SOUNDING STILL SHOWED PLENTY OF CAPE AND MOISTURE TO KEEP THE THREAT HIGH. PLUS WIND SHEAR ON THE MORNING SOUNDING LOOKS BETTER THAN RECENT MEMORY. WE STILL HAVE A FEW DEGREES OF WARMING LEFT TO GO SO ACTIVITY MAY HOLD OFF IN THE VALLEYS FOR ANOTHER 1 OR 3 HOURS...ALTHOUGH RADAR TRENDS HAVE INCREASED SINCE I BEGAN WRITING THIS DISCUSSION. THINKING THE STORMS ALONG THE RIM WILL GENERATE OUTFLOW BOUNDARIES THAT WILL EVENTUALLY PUSH WEST INTO THE LOWER TERRAIN AND MIX WITH THE MOIST UNSTABLE AIR. DOWNBURST WINDS ARE A CONCERN ALONG WITH THE POTENTIAL FOR BLOWING DUST. A FEW HAIL STONES ARE ALSO NOT OUT OF THE QUESTION. DEBRIS CLOUDS FROM THIS MORNING WERE TRACKING AT ABOUT 18KTS SO ANTICIPATE A SIMILAR STORM SPEED TODAY. STILL CONCERNED OVER LOCALIZED FLOODING EVEN WITH THE FASTER STORM MOTION. PRECIP WATER VALUES ARE UP AROUND 1.5 AND THE ACTIVITY MAY FORM INTO AN MCS LATER THIS AFTERNOON/EVENING AND INCREASE THE HEAVY RAIN THREAT. INCREASED POPS FOR TODAY ALONG A NORTHEAST TO SOUTHWEST LINE FROM GREENLEE COUNTY DOWN TO SOUTHERN PIMA. ALSO UPPED QPF AMOUNTS A TAD. THE NEXT BIG CONCERN IS THE HEAT FOR THE NEXT 5 TO 7 DAYS. WE WILL BE DANGEROUSLY CLOSE TO HEAT ADVISORY THRESHOLDS STARTING AS EARLY AS FRIDAY...WITH THE WARMEST CONDITIONS SATURDAY THROUGH MONDAY. ECMWF IS RUNNING WARMER THAN THE OTHER MODELS AND BASED ON THE 850-700MB THICKNESS REGRESSION METHOD...THE TUCSON AREA WILL HOVER AROUND 109 OR 110 SATURDAY THROUGH MONDAY. GFS THICKNESS VALUES ARE RUNNING ABOUT 10 DAM LOWER THAN THE EURO WHICH WOULD KEEP TEMPS DOWN BY ABOUT 4 DEGREES. WITH THE UPPER HIGH EXPECTED TO SIT OVER THE SW...WITH RIDGE AXIS GENERALLY PLANTED SQUARELY OVER THE STATE...AND THE EXPECTED DRYING CONDITIONS THROUGH THE WEEKEND...DECIDED TO ERR ON THE SIDE OF HOT AND INCREASED TEMPS TO JUST BELOW HEAT ADVISORY RANGE FROM SATURDAY THROUGH MONDAY. THESE HOT CONDITIONS MAY EVEN LAST INTO TUESDAY BEFORE THE RIDGE BREAKS DOWN. CONVECTION SHOULD BE RELEGATED TO THE MOUNTAINS WITH VERY LITTLE ACTIVITY REACHING THE LOWER DESERTS OR VALLEYS. CAN NOT COMPLETELY RULE OUT STORMS SO WILL CARRY THE LOW POPS THROUGH THE WEEK. && .AVIATION...SCT TO NUMEROUS -TSRA/-SHRA ESPECIALLY FROM KOLS TO KTUS NORTHEAST TOWARD GRAHAM AND GREENLEE COUNTIES. WIND GUSTS APPROACHING 55 KTS...POSSIBLY GREATER...WITH THE STRONGEST STORMS. OTHERWISE...VFR CONDITIONS AND SURFACE WIND GENERALLY LESS THAN 10 KTS THRU WEDNESDAY EVENING OR 09/06Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS THIS AFTERNOON AND EVENING. THEREAFTER...BUILDING HIGH PRESSURE ALOFT WILL CONFINE THUNDERSTORMS TO MAINLY NEAR HIGHER TERRAIN STARTING THURSDAY AND CONTINUING THROUGH THE WEEKEND. NORMAL DIURNAL WIND TRENDS OUTSIDE OF STRONG THUNDERSTORM OUTFLOWS. SHOWERS AND THUNDERSTORMS SHOULD INCREASE AGAIN THE FIRST HALF OF NEXT WEEK. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. JJB WEATHER.GOV/TUCSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1031 AM MST WED AUG 8 2012 AZZ501>515-090615- WESTERN PIMA COUNTY-TOHONO O'ODHAM NATION- UPPER SANTA CRUZ RIVER VALLEY/ALTAR VALLEY-TUCSON METRO AREA- SOUTH CENTRAL PINAL COUNTY-SOUTHEAST PINAL COUNTY- UPPER SAN PEDRO RIVER VALLEY- EASTERN COCHISE COUNTY BELOW 5000 FEET-UPPER GILA RIVER VALLEY- WHITE MOUNTAINS OF GRAHAM AND GREENLEE COUNTIES- GALIURO AND PINALENO MOUNTAINS-CHIRICAHUA MOUNTAINS- DRAGOON AND MULE AND HUACHUCA AND SANTA RITA MOUNTAINS- CATALINA AND RINCON MOUNTAINS-BABOQUIVARI MOUNTAINS- 1031 AM MST WED AUG 8 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA. .DAY ONE...TODAY AND TONIGHT EXPECT SCATTERED THUNDERSTORMS TO DEVELOP THIS AFTERNOON AND PUSH WEST ACROSS THE REGION THROUGH THIS EVENING. SOME OF THESE STORMS WILL BE STRONG TO SEVERE AND CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND HEAVY RAINFALL. THE THUNDERSTORM ACTIVITY IS EXPECTED TO DIMINISH ACROSS MOST AREAS BY MIDNIGHT. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY DECREASED THUNDERSTORM COVERAGE IS EXPECTED STARTING THURSDAY AND CONTINUING THROUGH THIS WEEKEND. THE MAIN WEATHER STORY DURING THIS PERIOD WILL CONTINUE TO BE THE VERY HOT TEMPERATURES IN THE LOWER ELEVATIONS WITH RECORD OR NEAR RECORD HIGHS POSSIBLE. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. WEATHER.GOV/TUCSON
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
335 PM MST WED AUG 8 2012
AZZ509>511-082300-
GALIURO AND PINALENO MOUNTAINS INCLUDING MOUNT GRAHAM AZ-UPPER GILA
RIVER AND ARAVAIPA VALLEYS INCLUDING CLIFTON/SAFFORD AZ-WHITE
MOUNTAINS OF GRAHAM AND GREENLEE COUNTIES INCLUDING HANNAGAN MEADOW
AZ-
335 PM MST WED AUG 8 2012
...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL GRAHAM COUNTY UNTIL 400
PM MST...
AT 327 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 12 MILES NORTHEAST OF SAFFORD...MOVING SOUTHWEST
AT 20 MPH.
WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM.
AREAS AFFECTED BY THIS STORM INCLUDE...SAFFORD...SOLOMON...FORT
THOMAS...THATCHER...SWIFT TRAIL JUNCTION...PIMA...FRYE MESA DAM AND
MOUNT GRAHAM.
LAT...LON 3273 10955 3261 10970 3280 11011 3299 11001
3310 10974 3296 10947
TIME...MOT...LOC 2235Z 035DEG 19KT 3294 10962SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE TUCSON AZ 341 PM MST WED AUG 8 2012 AZZ507-508-513-082315- DRAGOON/MULE/HUACHUCA AND SANTA RITA MOUNTAINS INCLUDING BISBEE/CANELO HILLS/MADERA CANYON AZ-EASTERN COCHISE COUNTY BELOW 5000 FEET INCLUDING DOUGLAS/WILLCOX AZ-UPPER SAN PEDRO RIVER VALLEY INCLUDING SIERRA VISTA/BENSON AZ- 341 PM MST WED AUG 8 2012 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN COCHISE COUNTY UNTIL 415 PM MST... AT 340 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 8 MILES SOUTHEAST OF SIERRA VISTA...MOVING WEST AT 10 MPH. WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN. AREAS AFFECTED BY THIS STORM INCLUDE...SIERRA VISTA...NICKSVILLE... CORONADO NATIONAL MEMORIAL AND RAMSEY CANYON PRESERVE. ANOTHER STRONG STORM WAS LOCATED SOUTH OF SAINT DAVID MOVING TOWARD KARTCHNER CAVERNS STATE PARK. THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. LAT...LON 3134 11045 3195 11044 3196 10998 3134 10991 TIME...MOT...LOC 2239Z 076DEG 10KT 3145 11023 KD
The Tucson radar (KEMX), 65 km away, was scanning. The volume nearest the first event began at 23:18 UTC.
3 thunderstorm wind. Local standard time, as filed.
Spotters in Hereford measured thunderstorm wind gusts to 62 mph and reported shingles blown off the roof of one house.
Thunderstorm winds downed power lines in far northeast Tucson leaving over 3000 residents without power.
Thunderstorm winds damaged several trees in Oro Valley, Marana and Casas Adobes on the northwest side of the Tucson metro area. A spotter near Oracle Junction measured a wind gust of 60 mph.
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, August 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: 408388, 408454, 408390.