Flash Flood and Damaging Wind in Arizona, August 10, 2001

Name: Flash Flood and Damaging Wind in Arizona, August 10, 2001
Start: 2001-08-10T17:03
End: 2001-08-10T18:00
Location: Arizona

August 10, 2001 · NWS TWC · 2 events in 1 county or zone

27 inches of rain in less than 20 minutes. 12 inches of rain in 30 minutes and that the washes were filling rapidly.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $10,000
Crop damage: None recorded
Events: 2

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.

What happened

The episode as NWS TWC wrote it up.

A spotter, located 10 miles south of Safford, reported 1.27 inches of rain in less than 20 minutes. Another spotter reported 1.12 inches of rain in 30 minutes and that the washes were filling rapidly. At the Safford airport, water had overflowed the runway with the storm water up to the wheels of the small aircrafts. The aiport rain gage registered 1.68 inches of rain in 30 minutes.

What forecasters said that day

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 10, 2:20 PM MST, 2 hours 43 minutes earlier.

Area forecast discussion, Aug 10, 2:20 PM MST, 2 hours 43 minutes before

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
220 PM MST FRI AUG 10 2001

.SYNOPSIS...AMPLE MOISTURE AND AN UPPER LEVEL DISTURBANCE MOVING
ACROSS NORTHERN ARIZONA WILL PROVIDE SCATTERED SHOWERS AND
THUNDERSTORMS TO MUCH OF SOUTHEAST ARIZONA TONIGHT. LIGHT WINDS
ALOFT IN COMBINATION WITH THE AMPLE MOISTURE WILL LEAD TO LOCALLY
HEAVY RAINFALL. HIGH PRESSURE ALOFT WILL BECOME CENTERED NEAR THE
FOUR CORNERS DURING THE WEEKEND. THIS FEATURE WILL BRING A NORTHEAST
TO EAST UPPER LEVEL WIND FLOW TO SOUTHEAST ARIZONA. THIS FLOW WILL
LEAD TO AN INCREASING CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS INTO EARLY NEXT WEEK.

.DISCUSSION...SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP AT THIS
TIME ACROSS MAINLY THE CENTRAL CWA...EAST OF A DUDLEYVILLE...TO
TUCSON...TO NOGALES LINE. SOUNDINGS FROM THIS MORNING INDICATE AN
EXTREMELY MOIST BUT MARGINALLY UNSTABLE ATMOSPHERE WITH PRECIPITABLE
WATER VALUES NEAR 2 INCHES. THE MAIN CONCERN THIS EVENING/TONIGHT IS
FOR HEAVY RAIN AND FLASH FLOODING. A SHORT WAVE TROUGH OVER NRN AZ
IS EXPECTED TO INCREASE ATMOSPHERIC LIFT TONIGHT. AM CONCERNED ABOUT
DEVELOPMENT ON THE RIM AND MOUNTAINS EAST OF TUCSON. ORGANIZATION
APPEARS LOOSE AT THIS TIME...HOWEVER EVENING SHIFT WILL NEED TO
MONITOR FOR CONSOLIDATION AND ADDITIONAL DEVELOPMENT. WILL MENTION
LOCALLY HEAVY RAINS IN ALL EXCEPT WRN ZONES WHERE ISOLATED
THUNDERSTORMS SHOULD PREVAIL. APPEARS SATURDAY WILL BE A DOWN-DAY AS
HIGH PRESSURE OVER NWRN AZ REPOSITIONS TOWARD THE FOUR CORNERS.
GENERIC LOW-GRADE MONSOON POPS TO RULE. ELY FLOW PROGGED TO INCREASE
SUN. THIS SCENARIO WILL PROVIDE AN INCREASED CHANCE OF SHOWERS AND
THUNDERSTORMS INTO EARLY NEXT WEEK. NO CHANGES TO THE EXTENDED
PERIOD.  BF

.TWC...NONE.

In the hours before

Special weather statement, Aug 10, 11:45 AM MST, 5 hours 18 minutes before

AZZ019-029>035-110700-

SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1145 AM MST FRI AUG 10 2001

.SYNOPSIS...THERE HAS BEEN LITTLE CHANGE IN THE WEATHER PATTERN
SINCE YESTERDAY. UPPER LEVEL HIGH PRESSURE REMAINS OVER NORTHWEST
ARIZONA...WITH A WEAKENING TROUGH OF LOW PRESSURE OVER NEW MEXICO
AND AN UPPER LEVEL DISTURBANCE PASSING ALONG THE ARIZONA-UTAH
BORDER. EXTENSIVE CLOUD COVER WILL KEEP INSTABILITY LIMITED...BUT
THE ATMOSPHERE WILL REMAIN VERY MOIST OVER THE REGION.

.DISCUSSION...A MESOSCALE CONVECTIVE SYSTEM WHICH DEVELOPED OVER THE
WESTERN MOGOLLON RIM LATE LAST NIGHT MOVED SOUTH ACROSS WESTERN
PINAL AND CENTRAL PIMA COUNTIES THIS MORNING. THE CLOUD COVER FROM
THIS COMPLEX SPREAD ACROSS ALL BUT THE FAR WESTERN AND EASTERN
PORTIONS OF THE AREA...BUT WAS THINNING OUT JUST BEFORE NOON.
SOUNDINGS FROM THIS MORNING INDICATE AN EXTREMELY MOIST BUT
MARGINALLY UNSTABLE ATMOSPHERE WITH PRECIPITABLE WATERS NEAR 2
INCHES. THE LACK OF INSTABILITY WILL LIMIT THE STRENGTH OF STORM
UPDRAFTS AND KEEP THE RISK OF SEVERE STORMS TO A MINIMUM. THE RISK
IS SLIGHTLY HIGHER OVER GRAHAM AND COCHISE COUNTIES WHERE A
TEMPERATURE CONTRAST HAS DEVELOPED BETWEEN THE CLOUDY SKIES NEAR
TUCSON AND CLEAR SKIES FURTHER EAST.

THE RISK FOR FLASH FLOODING...HOWEVER...IS CONSIDERABLY HIGHER THAN
CLIMATOLOGY ALONG THE RIM AND EAST OF TUCSON. AN UPPER LEVEL
DISTURBANCE CURRENTLY CROSSING NORTHERN ARIZONA IS EXPECTED TO
INCREASE ATMOSPHERIC LIFT TONIGHT. THIS DISTURBANCE HAS ALREADY
BEGUN TO IGNITE THUNDERSTORMS ON THE RIM AND MOUNTAINS EAST OF
TUCSON...WITH THE HELP OF A LITTLE MORE SUNSHINE. ALTHOUGH THEY
SHOULD REMAIN DISORGANIZED...ANY OF THESE STORMS COULD PRODUCE 2
INCHES OF RAIN PER HOUR. WE WILL CLOSELY MONITOR THE RIM THIS
AFTERNOON FOR POSSIBLE ORGANIZATION. IF STORMS UP THERE CONSOLIDATE
INTO A THUNDERSTORM COMPLEX AND START TO SHIFT SOUTH...A FLASH FLOOD
WATCH MAY BECOME NECESSARY. OTHER STORMS SHOULD REDEVELOP LATE THIS
AFTERNOON FROM TUCSON WEST. THEIR SLOW MOVEMENT WILL INCREASE THE
THREAT OF FLASH FLOODING SLIGHTLY ABOVE CLIMATOLOGY...BUT THE MORE
STABLE ATMOSPHERE WILL LIMIT THEIR STRENGTH AND KEEP ADDITIONAL
HEAVY RAINS ISOLATED.

STORM MOTION WILL BE GENERALLY SOUTHWEST AT 5 MPH. HOWEVER...SOME
CELL MERGERS AND COLLISIONS COULD OCCUR WHICH WOULD MAKE SOME STORMS
APPEAR STATIONARY.

PYTLAK

The radar

The Tucson radar (KEMX), 142 km away, was scanning. The volume nearest the first event began at 00:01 UTC.

Open the radar archive at this moment

Event by event

1 thunderstorm wind, 1 flash flood. Local standard time, as filed.

Thunderstorm Wind, Graham

When: August 10, 5:03 PM MST
Where: Graham County, Safford Arpt
Measured: 69 kt (79 mph)
Property damage: $10,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 32.850, -109.633

Damaging winds from a severe thunderstorm ripped off an awning from a mobile home and a large flourescent sign at an automobile dealership in Safford. Several 4 inch diameter tree branches were also broken in the Safford area. The 79 mph peak wind gust was reported at the Safford airport where several shingles were ripped off the two buildings.

Flash Flood, Graham

When: August 10, 5:20 PM MST to 6:00 PM MST
Where: Graham County, (E74)safford Arpt
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 32.933, -109.887 (the zone’s center; the record gives no point)

What these are

Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Arizona in 2001 Every state in 2001 This day in weather history Warnings in Arizona, August 2001

Sources

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: 5259907, 5259908.