Flash Flood and Debris Flow in Arizona, August 29, 2013

Name: Flash Flood and Debris Flow in Arizona, August 29, 2013
Start: 2013-08-29T17:00
End: 2013-08-29T18:40
Location: Arizona

August 29, 2013 · NWS TWC · 2 events in 2 counties and zones

A prominent ridge was in place over the center United States, with very moist air in place over southern Arizona. Precipitable water values were near 2 inches.

Where it happened

Every event with a place to put it. 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: $21,000
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 prominent ridge was in place over the center United States, with very moist air in place over southern Arizona. Precipitable water values were near 2 inches. Weak upper level flow caused storms to move slowly. Some storms produced 2 to 3 inches of rainfall, creating flash flooding.

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 29, 2:00 PM MST, 3 hours earlier.

Area forecast discussion, Aug 29, 2:00 PM MST, 3 hours before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST THU AUG 29 2013

.SYNOPSIS...DEEP MOISTURE IN COMBINATION WITH A SERIES OF IMPULSES
FROM THE SOUTH WILL BRING A BETTER CHANCE OF SHOWERS AND
THUNDERSTORMS AS WELL AS COOLER DAYTIME HIGHS THROUGH FRIDAY.
THEREAFTER...EXPECT A RETURN TO MORE TYPICAL MONSOON ACTIVITY AND
HOTTER TEMPERATURES SATURDAY INTO NEXT WEEK.

&&

.DISCUSSION...THIS MORNINGS KTWC SOUNDING WAS VERY MOIST WITH A
PRECIPITABLE WATER VALUE OF 1.95 INCHES...AN INCREASE OF 0.51 INCHES
IN 24 HOURS. THE SOUNDING ALSO SHOWED SIGNIFICANT COOLING FROM
AROUND 625MB TO THE SURFACE. THAT SAID...EXPECTING HIGH TEMPERATURES
TO BE SIGNIFICANTLY COOLER THAN YESTERDAY.

IR AND VISIBLE SATELLITE IMAGERY SHOWS EXTENSIVE MOSTLY MID LEVEL
CLOUDINESS ASSOCIATED WITH THE INVERTED TROUGH COVERING MUCH OF
NORTHERN MEXICO...THE SOUTHEAST HALF OF ARIZONA AND THE WESTERN
2/3RDS OF NEW MEXICO. RADAR MOSAIC IS DETECTING ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS AT THIS TIME ACROSS
PORTIONS OF SOUTHEAST ARIZONA...WITH MOST OF THE ACTIVITY EXTENDING
WEST TO EAST ACROSS THE ENTIRE LENGTH OF PIMA COUNTY INTO COCHISE
COUNTY...WITH ADDITIONAL SHOWERS AND STORMS OVER NORTHEAST SONORA...
NORTHWEST CHIHUAHUA AND SOUTHERN NEW MEXICO ALL MOVING GENERALLY TO
THE NORTH.

AS THE DAY PROGRESSES...SHOWER AND THUNDERSTORM ACTIVITY WILL
CONTINUE TO INCREASE...BECOMING SCATTERED...TO NUMEROUS AT TIMES FOR
THE REMAINDER OF THIS AFTERNOON AND INTO THE EVENING HOURS...WITH A
SLIGHT DOWNSWING IN THE ACTIVITY OVERNIGHT INTO EARLY FRIDAY.
LOCALIZED FLOODING WILL BE THE MAIN CONCERN THROUGH THIS EVENING
WITH SUCH A 'JUICY' AIRMASS IN PLACE. EXPECTING RAINFALL AMOUNTS TO
AVERAGE AROUND A THIRD OF AN INCH UP TO AROUND THREE QUARTERS OF AN
INCH WITH MOST OF THE STORMS...BUT A FEW WILL BE CAPABLE OF
PRODUCING AMOUNTS WELL IN EXCESS OF 1.5 INCHES. THE STORMS ARE
MOVING AT A DECENT PACE...WHICH SHOULD MITIGATE ANY SERIOUS FLOODING
ISSUES...BUT LOCALIZED FLOODING PROBLEMS NOT OUT OF THE QUESTION FOR
LATE THIS AFTERNOON AND INTO THE EVENING HOURS WITH THE STRONGEST
STORMS.

MODELS CONTINUE TO SHOW THE INVERTED TROUGH LIFTING TO THE NORTH AND
NORTHWEST THROUGH THIS EVENING WITH SHOWERS AND THUNDERSTORMS
LINGERING THROUGH THE OVERNIGHT HOURS...BUT NOT AS NUMEROUS. ANOTHER
UPSWING IN ACTIVITY EXPECTED AGAIN ON FRIDAY...ESPECIALLY DURING THE
AFTERNOON HOURS...BUT THE COVERAGE IS NOT EXPECTED TO BE AS NUMEROUS
ON FRIDAY COMPARED TO THIS AFTERNOON AND EVENING.

BY THIS WEEKEND THE CENTER OF HIGH PRESSURE...WHICH CURRENTLY
RESIDES OVER ARKANSAS WILL RETROGRADE TO NEW MEXICO FOR INCREASING
HIGH TEMPERATURES AS THE AIRMASS DRIES OUT (RELATIVELY SPEAKING)
FROM THE NEAR 2 INCH PW'S CURRENTLY...TO AROUND 0.6 - 0.75 FOR AREAS
RIGHT ALONG THE NEW MEXICO BORDER TO AROUND 1.75 INCHES FOR THE FAR
WESTERN DESERTS OF PIMA COUNTY BY WEDNESDAY. THAT SAID...AFTER
SUNDAY RAIN CHANCES SHOULD FALL BACK DOWN TO MORE TYPICAL
VALUES...WITH ISOLATED TO LOW END SCATTERED ACTIVITY FOR
DESERTS/VALLEYS AND GOOD CHANCES FOR MOUNTAIN TOPS.

HIGHS ABOUT 3 TO 5 DEGS BELOW NORMAL FOR FRIDAY...THEN NEAR NORMAL
FOR SATURDAY. THEREAFTER...HIGHS ABOVE NORMAL WITH THE WARMEST DAY
OCCURRING ON THURSDAY WHEN HIGHS WILL BE ABOUT 4 TO 6 DEGS ABOVE
NORMAL. LOWS WILL RANGE FROM 3 TO 5 DEGS THROUGH THE PERIOD.

&&

.AVIATION...SCT-BKN CLOUDS AT 4-8K FT AGL AND BKN-OVC CLOUDS AT
10-14K FT AGL THRU 30/14Z...THEN SCT-BKN CLOUDS AT 5-9K FT AGL.
NUMEROUS TSRA/SHRA WILL OCCUR THRU THE LATE EVENING HOURS TONIGHT...
WITH SCATTERED TSRA/SHRA OVERNIGHT AND FRIDAY. THE STRONGER TSRA
WILL PRODUCE IFR CIGS/VSBYS AND WIND GUSTS TO NEAR 40 KTS.
OTHERWISE...SELY/SLY SURFACE WIND AT 5-15 KTS THRU FRIDAY AFTERNOON
OR 30/19Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE
EXPECTED INTO FRIDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS
PERSISTING INTO NEXT WEEK. STRONG...GUSTY AND ERRATIC WINDS WILL
OCCUR WITH THE STRONGER THUNDERSTORMS. 20-FOOT WINDS WILL BE SOUTH
TO SOUTHEAST AT 5 TO 15 MPH THROUGH FRIDAY MORNING. THEREAFTER...
NORMAL DIURNAL WIND TRENDS WILL RETURN TO SOUTHERN ARIZONA THIS
WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...ZELL

The radar

The Tucson radar (KEMX), 78 km away, was scanning. The volume nearest the first event began at 00:03 UTC.

Open the radar archive at this moment

Event by event

1 flash flood, 1 debris flow. Local standard time, as filed.

Flash Flood, Cochise

When: August 29, 5:00 PM MST to 6:00 PM MST
Where: Cochise County, 5.48 mi NW of Cochise Co Arpt to 8.29 mi WNW of Willcox
Cause: Heavy Rain
Property damage: $20,000
Reported by: Newspaper
Coordinates: 32.296, -109.953

Two to three inches of rain in less than an hour caused flash flooding northwest of Willcox. The home of a family of four was flooded. As they attempted to escape in their sport utility vehicle, water was nearly waste high. They drove toward Willcox but became stranded in flood waters along Old Stewart Road and needed to be rescued. The next day, another vehicle became stranded in standing water in the same location. The man was able to swim to safety. No injuries were reported in either incident.

Debris Flow, Greenlee

When: August 29, 6:40 PM MST
Where: Greenlee County, 0.36 mi NNE of Clifton to 0.33 mi N of Clifton
Cause: Heavy Rain
Property damage: $1,000
Reported by: Newspaper
Coordinates: 33.055, -109.299

Brief heavy rain caused mud to slide downhill, temporarily closing Highway 191 in Clifton near the old train depot. Debris was up to four feet deep across the roadway.

What these are

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.
Debris Flow: A fast-moving slurry of mud, rock and debris, usually on a slope soaked by heavy rain or stripped by a fire.

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

The same day elsewhere

Every storm in Arizona in 2013 Every state in 2013 This day in weather history Warnings in Arizona, August 2013

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: 475122, 475127.