Arizona, 2012Flash Flood and Heavy Rain in Arizona, September 4, 2012
September 4, 2012 · NWS TWC · 2 events in 1 county or zone
75 inches of precipitable water and weak upper level winds remained across southern Arizona. Thunderstorms developed early in the morning over saturated areas that had received rain the prior afternoon and evening, resulting in flash flooding.
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
- Deaths
- 0
- Injuries
- 1
- Property damage
- $16,000
- 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.
Abundant moisture of 1.75 inches of precipitable water and weak upper level winds remained across southern Arizona. Thunderstorms developed early in the morning over saturated areas that had received rain the prior afternoon and evening, resulting in 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 Sep 4, 1:45 AM MST, 5 hours 45 minutes earlier.
Area forecast discussion, Sep 4, 1:45 AM MST, 5 hours 45 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
145 AM MST TUE SEP 4 2012
.SYNOPSIS...DEEPER MOISTURE WILL CONTINUE TO PROVIDE AN UPSWING IN
THUNDERSTORM ACTIVITY ACROSS THE AREA THROUGH THURSDAY.
&&
.DISCUSSION...WATER VAPOR IMAGERY AND 04/00Z UPPER-AIR PLOTS
CONTINUE TO SHOW A RIDGE OVER CENTRAL TEXAS WITH A TROUGH OVER THE
PACIFIC NORTHWEST AND MOIST SOUTHWEST FLOW OVER THE DESERT SOUTHWEST
BETWEEN THESE TWO SYSTEMS. THE LATEST IR SATELLITE IMAGERY AND RADAR
MOSAIC SHOWS ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS
CONTINUING ACROSS MAINLY CENTRAL AND SOUTHERN PORTIONS OF THE
FORECAST AREA AND DRIFTING TO THE SOUTH AND WEST.
THE SATELLITE DERIVED BLENDED TOTAL PRECIPITABLE WATER PRODUCT
CONTINUES TO INDICATE HIGH VALUES ACROSS MUCH OF THE SOUTHWEST WITH
READINGS WELL IN EXCESS OF 2 INCHES OVER THE NORTHERN GULF OF
CALIFORNIA AND INTO SOUTH CENTRAL SONORA. OVER SOUTHERN AND CENTRAL
ARIZONA VALUES ARE GENERALLY AROUND 1.6 INCHES WITH LOWER VALUES
FARTHER NORTHWEST THROUGH THE EAST...BUT EVEN THEN OVER THE ONE INCH
MARK.
MODELS INDICATE THE MOISTURE WILL CONTINUE TO LINGER ACROSS THE AREA
AS THE HIGH RECONSOLIDATES FARTHER WEST AND EXTENDS FROM EASTERN
ARIZONA INTO WEST TEXAS TODAY. MEANWHILE...AN INVERTED TROUGH OVER
NORTH CENTRAL MEXICO WILL CONTINUE TO MOVE IN A WESTERLY OR
NORTHWESTERLY DIRECTION TOWARD OR THROUGH SOUTHERN SONORA AND
NORTHERN BAJA THROUGH LATE THURSDAY. AS A RESULT...EXPECTING TO SEE
AN INCREASE IN ACTIVITY TODAY THROUGH THURSDAY...ESPECIALLY ALONG
THE INTERNATIONAL BORDER. BY LATE IN THE WEEK AND INTO THE WEEKEND
THE HIGH SHOULD BE OVER NORTHERN ARIZONA OR WESTERN NEW MEXICO. WE
WILL LIKELY SEE A DECREASE IN RAIN CHANCES BEGINNING ON FRIDAY AND
CONTINUING INTO EARLY NEXT WEEK...BUT STILL AT LEAST ISOLATED
COVERAGE FOR DESERTS/VALLEYS AND LOW END SCATTERED COVERAGE FOR THE
HIGHER ELEVATIONS.
HIGH TEMPERATURES GENERALLY AROUND 2 TO 4 DEGS BELOW NORMAL TODAY
THROUGH FRIDAY...THEN NEAR NORMAL ON SATURDAY. THEREAFTER...NEAR OR
SLIGHTLY ABOVE NORMAL SUNDAY AND MONDAY. LOWS WILL BE ABOUT 3 TO 4
DEGS ABOVE NORMAL EACH DAY.
&&
.AVIATION...ISOLD TSRA/SHRA CONTINUING THROUGH THE OVERNIGHT HOURS.
EXPECT SCT TSRA TO REDEVELOP ONCE AGAIN THIS AFTERNOON...GENERALLY
AROUND 04/19Z. CLOUDS SCT-BKN 10-12K FT THROUGH AROUND 18Z...THEN
SCT 8-10K FT WITH CEILINGS AT AROUND 12-15K FT. CEILINGS LOWER NEAR
THUNDERSTORMS. NORMAL DIURNAL WIND TRENDS EXCEPT FOR STRONG ERRATIC
THUNDERSTORM OUTFLOWS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS THROUGH THE WEEK. ERRATIC AND GUSTY WINDS
CAN BE EXPECTED NEAR ANY THUNDERSTORMS THAT DEVELOP.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/TUCSON
MOLLERE
Hazardous weather outlook, Sep 3, 11:20 AM MST, 20 hours 10 minutes before
HAZARDOUS WEATHER OUTLOOK...CORRECTION
NATIONAL WEATHER SERVICE TUCSON AZ
1120 AM MST MON SEP 3 2012
CORRECTION TO ADD SECOND PARAGRAPH IN DAY TWO THRU SEVEN SECTION
AZZ503-507-508-513-040600-
UPPER SANTA CRUZ RIVER VALLEY/ALTAR VALLEY-
UPPER SAN PEDRO RIVER VALLEY-
EASTERN COCHISE COUNTY BELOW 5000 FEET-
DRAGOON AND MULE AND HUACHUCA AND SANTA RITA MOUNTAINS-
1120 AM MST MON SEP 3 2012
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA.
.DAY ONE...TODAY AND TONIGHT
MOISTURE VALUES HAVE INCREASED IN THE PAST 24 HOURS AND COMBINED
WITH A WEAK UPPER LEVEL DISTURBANCE MOVING NORTH ACROSS NORTHERN
SONORA MEXICO...EXPECTED WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS THIS AFTERNOON AND EVENING. SOME OF THE STRONGER
STORMS WILL PRODUCE HEAVY RAIN AND WIND GUSTS TO 50 MPH. LOCALIZED
RAINFALL TOTALS OF ONE TO TWO INCHES WILL INCREASE THE CHANCES FOR
FLASH FLOODING TO OCCUR.
.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
DEEPER MOISTURE WILL MOVE ACROSS THE AREA TUESDAY AND WEDNESDAY.
THUS EXPECT TYPICAL SUMMER THUNDERSTORM ACTIVITY. MAIN THREAT FROM
STORMS WILL BE HEAVY RAIN AND WIND GUSTS TO 45 MPH. THERE WILL BE
FLASH FLOODING CONCERNS BOTH TUESDAY AND WEDNESDAY.
SOME DRIER AIR PUSHES IN THURSDAY INTO THE WEEKEND...BUT ENOUGH
MOISTURE WILL BE AROUND FOR A CHANCE OF STORMS EACH AFTERNOON AND
EVENING.
.SPOTTER INFORMATION STATEMENT...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
AZZ502-515-040600-
TOHONO O'ODHAM NATION-BABOQUIVARI MOUNTAINS-
1120 AM MST MON SEP 3 2012
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA.
.DAY ONE...TODAY AND TONIGHT
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE DEVELOPING THIS AFTERNOON
AND CONTINUING INTO THE EVENING HOURS. AS HAS BEEN THE CASE FOR
THE PAST COUPLE OF DAYS...SOME OF THESE STORMS WILL CAPABLE OF
PRODUCING HEAVY RAIN AND WIND GUSTS TO 50 MPH. ISOLATED AREAS OVER
THE PAST COUPLE OF EVENINGS HAVE RECEIVED UP TO TWO INCHES OF
RAIN...SO ANY ADDITIONAL RAINFALL WILL BRING ABOUT FLASH FLOODING
ISSUES.
.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
DEEPER MOISTURE WILL MOVE ACROSS THE AREA TUESDAY AND WEDNESDAY.
THUS EXPECT TYPICAL SUMMER THUNDERSTORM ACTIVITY. MAIN THREAT FROM
STORMS WILL BE HEAVY RAIN AND WIND GUSTS TO 45 MPH. THERE WILL BE
FLASH FLOODING CONCERNS BOTH TUESDAY AND WEDNESDAY.
SOME DRIER AIR PUSHES IN THURSDAY INTO THE WEEKEND...BUT ENOUGH
MOISTURE WILL BE AROUND FOR A CHANCE OF STORMS EACH AFTERNOON AND
EVENING.
.SPOTTER INFORMATION STATEMENT...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
AZZ504>506-514-040600-
TUCSON METRO AREA-SOUTH CENTRAL PINAL COUNTY-
SOUTHEAST PINAL COUNTY-CATALINA AND RINCON MOUNTAINS-
1120 AM MST MON SEP 3 2012
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA.
.DAY ONE...TODAY AND TONIGHT
ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
DEVELOPING THIS AFTERNOON AND CONTINUING INTO THE EVENING HOURS.
MAIN THREAT FROM STORMS WILL BE WIND GUSTS TO 50 MPH AND BRIEF
HEAVY RAIN WHICH MAY CAUSE MINOR FLOODING ISSUES.
.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
DEEPER MOISTURE WILL MOVE ACROSS THE AREA TUESDAY AND WEDNESDAY.
THUS EXPECT TYPICAL SUMMER THUNDERSTORM ACTIVITY. MAIN THREAT FROM
STORMS WILL BE HEAVY RAIN AND WIND GUSTS TO 45 MPH. THERE WILL BE
FLASH FLOODING CONCERNS BOTH TUESDAY AND WEDNESDAY.
SOME DRIER AIR PUSHES IN THURSDAY INTO THE WEEKEND...BUT ENOUGH
MOISTURE WILL BE AROUND FOR A CHANCE OF STORMS EACH AFTERNOON AND
EVENING.
.SPOTTER INFORMATION STATEMENT...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
AZZ501-040600-
WESTERN PIMA COUNTY-
1120 AM MST MON SEP 3 2012
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA.
.DAY ONE...TODAY AND TONIGHT
THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS THIS AFTERNOON...THEN A
BETTER CHANCE TONIGHT AS STORMS IN CENTRAL PIMA COUNTY PUSH WEST
AS FAR AS STATE HIGHWAY 86. MAIN THREAT FROM STORMS INITIALLY WILL
BE BLOWING DUST FROM THUNDERSTORM OUTFLOW TO THE EAST...THEY
LOCALLY HEAVY RAIN AND WIND GUSTS TO 45 MPH AS STORMS PUSH WEST
ACROSS THE AREA.
.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
DEEPER MOISTURE WILL MOVE ACROSS THE AREA TUESDAY AND WEDNESDAY.
THUS EXPECT TYPICAL SUMMER THUNDERSTORM ACTIVITY. MAIN THREAT FROM
STORMS WILL BE HEAVY RAIN AND WIND GUSTS TO 45 MPH. THERE WILL BE
FLASH FLOODING CONCERNS BOTH TUESDAY AND WEDNESDAY.
SOME DRIER AIR PUSHES IN THURSDAY INTO THE WEEKEND...BUT ENOUGH
MOISTURE WILL BE AROUND FOR A CHANCE OF STORMS EACH AFTERNOON AND
EVENING.
.SPOTTER INFORMATION STATEMENT...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
AZZ509>512-040600-
UPPER GILA RIVER VALLEY-
WHITE MOUNTAINS OF GRAHAM AND GREENLEE COUNTIES-
GALIURO AND PINALENO MOUNTAINS-CHIRICAHUA MOUNTAINS-
1120 AM MST MON SEP 3 2012
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA.
.DAY ONE...TODAY AND TONIGHT
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING. LOCALLY HEAVY RAIN AND WIND GUSTS TO 45 MPH ARE MAIN
CONCERNS WITH STORMS.
.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
DEEPER MOISTURE WILL MOVE ACROSS THE AREA TUESDAY AND WEDNESDAY.
THUS EXPECT TYPICAL SUMMER THUNDERSTORM ACTIVITY. MAIN THREAT FROM
STORMS WILL BE HEAVY RAIN AND WIND GUSTS TO 45 MPH. THERE WILL BE
FLASH FLOODING CONCERNS BOTH TUESDAY AND WEDNESDAY.
SOME DRIER AIR PUSHES IN THURSDAY INTO THE WEEKEND...BUT ENOUGH
MOISTURE WILL BE AROUND FOR A CHANCE OF STORMS EACH AFTERNOON AND
EVENING.
.SPOTTER INFORMATION STATEMENT...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
WEATHER.GOV/TUCSON
Heavy Rain, Pima
- When
- September 4, 7:30 AM MST to 7:55 AM MST
- Where
- Pima County, 1.41 mi ESE of Continental to 1.13 mi NW of Continental
- Injuries
- 0 direct, 1 indirect
- Property damage
- $15,000
- Reported by
- Newspaper
- Coordinates
- 31.842, -110.958
The second heavy rain of the morning overwhelmed a roof drain system on Continental School in Green Valley. Ceiling tiles collapsed from the weight of the rain and carpets were damaged. In addition, a motorist lost control of a vehicle in heavy rain along Interstate 19 near Green Valley. The vehicle left the roadway and crashed into a small tree, injuring the driver.
Flash Flood, Pima
- When
- September 4, 8:30 AM MST to 9:30 AM MST
- Where
- Pima County, 1.81 mi W of Continental to 2.51 mi ESE of San Xavier
- Cause
- Heavy Rain
- Property damage
- $500
- Reported by
- Newspaper
- Coordinates
- 31.845, -111.010
During the morning hours, brief but heavy rain fell on saturated ground, causing washes to quickly fill and flow across roads. Portions of Camino Del Sol and Mission Roads were closed due to flooding in and near Green Valley.
- Heavy Rain
- Rainfall totals unusual for the place and season that did not produce a flood.
- 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.
- Tornado and Hail in Wisconsin, September 4 to 5, 2012$501,000 · EF2 · 25 events
- Hail and Damaging Winds in Minnesota, September 4 to 5, 2012$745,000 · 2.5 in hail · 20 events
- Hail and Damaging Winds in Wisconsin, September 4 to 5, 2012$155,000 · 56 kt wind · 27 events
- Hail and Damaging Winds in Kansas, September 4, 2012$285,000 · 61 kt wind · 11 events
- Flash Flooding and Damaging Wind in Arizona, September 4 to 5, 20121 injured · $280,000 · 70 kt wind · 3 events
- Damaging Winds in Oklahoma, September 4, 2012$405,000 · 70 kt wind · 3 events
- Hail and Damaging Winds in Iowa, September 4 to 5, 2012$183,000 · 64 kt wind · 17 events
- High Wind in Alaska, September 4 to 5, 2012$200,000 · 113 kt wind · 1 event
- Damaging Winds in Minnesota, September 4, 2012$100,000 · 61 kt wind · 4 events
- Flash Flood in Arizona, September 4, 2012$100,000 · 1 event
- Hail and Damaging Winds in Nebraska, September 4, 2012$75,000 · 56 kt wind · 4 events
- Tornado and Damaging Wind in New Jersey, September 4, 2012$32,000 · EF0 · 5 events
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: 413884, 413883.