Moist southerly flow interacted with the mountains of southern Arizona to produce isolated thunderstorms. Some of the storms produced strong winds and heavy rainfall.
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.
Moist southerly flow interacted with the mountains of southern Arizona to produce isolated thunderstorms. Some of the storms produced strong winds and heavy rainfall.
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 Sep 1, 2:00 PM MST, 2 hours 41 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 200 PM MST THU SEP 1 2011 .SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORM ACTIVITY WILL REMAIN ACROSS SOUTHEAST ARIZONA INTO THE WEEKEND WITH ABOVE AVERAGE TEMPERATURES CONTINUING. && .DISCUSSION...A LITTLE SLOWER CLEARING OUT BUT PLENTY OF SUNSHINE BY EARLY AFTERNOON...TRAILING A DEGREE OR THREE BEHIND YESTERDAY AS WELL. CONVECTION HAS BEEN SLOWER TO DEVELOP BUT SIMILAR TO YESTERDAY OTHERWISE WITH DISTRIBUTION AND STORM MOVEMENT. SHOULD HAVE SOME SUPPORT FOR STORMS IN VALLEYS AFTER CURRENT MOUNTAIN DEVELOPMENT. LOCALLY HEAVY RAINFALL STILL A CONCERN ALONG WITH ISOLATED WET MICROBURST ACTIVITY. HEAT STILL AN ISSUE INTO NEXT WEEK AS HEIGHT AND THICKNESSES KEEP TEMPERATURES 6 TO 8 DEGREES ABOVE CLIMO. NO BIG MECHANISM TO IMPORT MOISTURE SO WHILE THERE IS ENOUGH IN PLACE NOW WE MAY SEE THAT SLOWLY DWINDLE OVER THE NEXT WEEK OR SO. MEDIUM RANGE MODELS KEEP HIGH PRESSURE IN CONTROL WITH ABOVE AVERAGE TEMPERATURES AND LESS THAN OPTIMAL CONDITIONS FOR WIDESPREAD RAINFALL. && .AVIATION...SCT-BKN CLOUDS AT 6-10K FT AGL TIL 06Z FRIDAY...THEN SLOWLY DECREASING CLOUDS THROUGH 14Z FRIDAY. ISOLATED TO SCATTERED TSRA/SHRA THROUGH 03Z FRIDAY...WITH TSRA/SHRA DIMINISHING BETWEEN 03Z-06Z FRIDAY. EXPECT BKN-OVC CEILINGS AT 4-7K FT AGL NEAR TSRA/SHRA...WITH MVFR CIGS/VSBYS NEAR THE STRONGER STORMS. SURFACE WIND GENERALLY LESS THAN 10 KTS...EXCEPT STRONG AND GUSTY NEAR THUNDERSTORMS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE EASTERN TWO-THIRDS OF THE FORECAST AREA THROUGH THE UPCOMING WEEKEND. NORMAL DIURNAL WIND TRENDS ARE FORECASTED... EXCEPT FOR STRONG AND GUSTY WINDS NEAR THUNDERSTORMS. A GRADUAL LOWERING OF DAYTIME HIGH TEMPERATURES IS EXPECTED THE NEXT COUPLE OF DAYS...ALTHOUGH READINGS WILL REMAIN MUCH ABOVE NORMAL THROUGH THE WEEKEND. && .CLIMATE...THE AUGUST CLIMATE REPORT HAS BEEN POSTED LATER TODAY ON OUR WEBSITE WITH MAIN HIGHLIGHT BEING TUCSON RECORDING 2ND HOTTEST AUGUST AND METEOROLOGICAL SUMMER. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. WEATHER.GOV/TUCSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1109 AM MST THU SEP 1 2011 AZZ503>515-021815- 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- 1109 AM MST THU SEP 1 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA. .DAY ONE...THIS AFTERNOON AND TONIGHT ANOTHER DAY WITH TEMPERATURES WELL ABOVE SEASONAL NORMALS. SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE OFF OF THE HIGHER TERRAIN AND INTO SOME VALLEY LOCATIONS TODAY. SOME STORMS WILL GENERATE LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS. PLEASE NOTE THAT EVEN MODERATE RAINFALL OVER THE RECENT BURN AREAS COULD RESULT IN FLASH FLOODING. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY HOT AFTERNOONS WILL CONTINUE. THERE WILL BE SUFFICIENT MOISTURE FOR A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. PLEASE NOTE THAT EVEN MODERATE RAINFALL OVER THE RECENT BURN AREAS COULD RESULT IN FLASH FLOODING. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. AZZ501-502-021815- WESTERN PIMA COUNTY-TOHONO O'ODHAM NATION- 1109 AM MST THU SEP 1 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA. .DAY ONE...THIS AFTERNOON AND TONIGHT ANOTHER DAY WITH TEMPERATURES WELL ABOVE SEASONAL NORMALS. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATER IN THE AFTERNOON AND EVENING HOURS...ESPECIALLY IN EASTERN AREAS. SOME STORMS MAY GENERATE STRONG GUSTY WINDS AND LOCALLY HEAVY RAINFALL. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY HOT AFTERNOONS WILL CONTINUE. A FEW SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE MAINLY DURING AFTERNOON AND EVENING HOURS. .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
413 PM MST THU SEP 1 2011
AZZ507-513-020000-
DRAGOON/MULE/HUACHUCA AND SANTA RITA MOUNTAINS INCLUDING
BISBEE/CANELO HILLS/MADERA CANYON AZ-UPPER SAN PEDRO RIVER VALLEY
INCLUDING SIERRA VISTA/BENSON AZ-
413 PM MST THU SEP 1 2011
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN COCHISE COUNTY UNTIL
500 PM MST...
AT 410 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR SIERRA VISTA...MOVING WEST AT 10 MPH.
WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM.
AREAS AFFECTED BY THIS STORM INCLUDE...SIERRA VISTA...HUACHUCA
CITY...NICKSVILLE...RAMSEY CANYON PRESERVE AND FORT HUACHUCA.
THIS STORM 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 3144 11040 3166 11036 3164 11014 3155 11012
3143 11013
TIME...MOT...LOC 2313Z 079DEG 9KT 3153 11026
BFThe Tucson radar (KEMX), 49 km away, was scanning. The volume nearest the first event began at 23:42 UTC.
1 thunderstorm wind. Local standard time, as filed.
Strong thunderstorm winds resulted in several downed trees along Fry Blvd. in Sierra Vista. Some of the trees were blocking the driving lanes on Fry Blvd.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2011Every state in 2011This day in weather historyWarnings in Arizona, September 2011
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: 347551.