Alert archive / Arizona / Flash Flood Warnings in 2007

Flash Flood Warning 31, NWS Tucson, AZ

July 31, 2007Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 31, 2007, 4:02 PM MST for Pima County, Arizona. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 31, 2007, 4:02 PM MST (23:02 UTC)
Expired: Jul 31, 2007, 7:00 PM MST
In force: 3 hr
Issued by: NWS Tucson, AZ
Area: Counties, with a storm outline in the text
Flood severity: None

County Pima County, AZ

The radar

The Phoenix radar (KIWA), 118 km from the middle of the area, began a volume at 23:04 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 11.0 hours before the alert went out and 118 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 231 J/kg
Mixed-layer CIN: -54 J/kg
Mixed-layer LCL: 1229 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 64 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS55 KTWC 312307
FFWTWC
AZC019-010200-
/X.NEW.KTWC.FF.W.0031.070731T2302Z-070801T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
405 PM MST TUE JUL 31 2007

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL PIMA COUNTY IN SOUTH CENTRAL ARIZONA...

* UNTIL 700 PM MST

* AT 400 PM MST...SURFACE REPORTS INDICATED ONGOING FLASH FLOODING   
  OVER NORTHERN PORTIONS OF THE TOHONO OODHAM NATION. THE HARDEST    
  HIT AREA WAS NEAR THE VILLAGE OF HICKIWAN...WHERE HICKIWAN WASH    
  ROSE OVER 7 FEET IN AN HOUR AND A HALF. THE AREA RECEIVED OVER 3   
  INCHES OF RAIN EARLIER THIS AFTERNOON BASED ON DOPPLER RADAR       
  ESTIMATES. IN ADDITION...1 TO 2 INCHES OF RAIN FELL EARLIER        
  BETWEEN VENTANA AND ANEGAM IN NORTH CENTRAL PORTIONS OF THE        
  NATION...WITH ANOTHER 1 TO 2 INCHES JUST WEST OF SILVERBELL. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO VENTANA... 
  SANTA ROSA...AND SAN SIMON VILLAGE.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

THIS WARNING REPLACES THE PREVIOUSLY ISSUED FLASH FLOOD WARNING FOR 
NORTHERN SECTIONS OF THE TOHONO OODHAM NATION.

LAT...LON 3218 11254 3217 11224 3227 11150 3251 11151
      3250 11254

$$
PYTLAK

WEATHER.GOV/TUCSON

1 follow-up statement

000 
WGUS75 KTWC 010158
FFSTWC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
654 PM MST TUE JUL 31 2007

AZC019-010204-
/X.EXP.KTWC.FF.W.0031.000000T0000Z-070801T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PIMA AZ-
654 PM MST TUE JUL 31 2007

...THE FLASH FLOOD WARNING WILL EXPIRE AT 700 PM MST FOR NORTH
CENTRAL PIMA COUNTY...

AT 624 PM MST RAINFALL HAD ENDED OVER THE TOHONO OODHAM NATION. 
HOWEVER...BETWEEN 1 AND 2 INCHES OF RAIN ALSO FELL IN UPPER REACHES 
OF CHILDS WASH NORTHEAST OF AJO...BETWEEN VENTANA AND ANEGAM ALONG 
SANTA ROSA WASH...AND JUST NORTHWEST OF SILVERBELL. 

RUNOFF FROM EARLIER RAINFALL WILL KEEP WASHES FLOWING AND PONDING 
NEAR LOW WATER CROSSINGS.

LAT...LON 3218 11254 3217 11224 3227 11150 3251 11151
      3250 11254

$$

WEATHER.GOV/TUCSON
CS

What forecasters said that day

The local office's own words before this flash flood warning went out, 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 this flash flood warning went out at Jul 31, 1:35 PM MST, 2 hours 27 minutes earlier.

Area forecast discussion, Jul 31, 1:35 PM MST, 2 hours 27 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
135 PM MST TUE JUL 31 2007

.SYNOPSIS...COPIOUS MOISTURE AND WEAK DISTURBANCES ALOFT WILL KEEP
THE REGION IN AN ACTIVE MONSOON PATTERN THROUGH THE WEEK. EARLY NEXT
WEEK THE MEDIUM RANGE FORECAST MODELS INDICATE A DRYING TREND
RESULTING IN A LOWER CHANCE FOR THUNDERSTORMS.

&&

.DISCUSSION...THUNDERSTORM DEVELOPMENT HAS BEGUN TODAY SPARKED BY
COPIOUS MOISTURE AND WEAK DISTURBANCES WHICH HAVE PROVIDED THE
DYNAMICS NEEDED FOR THE EARLY START. HEAVY RAIN IS THE MAIN THREAT
LEADING TO SMALL STREAM AND FLASH FLOODING...ALTHOUGH THERE IS AN
OFF CHANCE OF A WET MICROBURST. SO FAR RAINFALL RATES ON THE
MOUNTAINS HAVE BEEN UP TO 2 INCHES PER HOUR AND UP TO 1 INCH PER
HOUR IN THE VALLEYS. THIS IS RIGHT IN LINE WITH HPC/S QPFERD.

THE TWO WEAK CIRCULATIONS...ONE LOCATED SOUTH OF DOUGLAS MOVING
NORTH AND THE OTHER JUST EAST OF HANNAGAN MEADOW WILL CONTINUE TO
PROVIDE DIFFLUENCE ALOFT FOR GREATER UPWARD MOTION. THE DRY PUNCH
ALOFT SOUTH OF DOUGLAS HAS BEGUN TO INITIATE CONVECTION AS IT MOVES
INTO THE DIFFLUENCE ZONE. ON WATER VAPOR IMAGERY ONE CAN SEE THE
LINE OF CONVECTION ALONG THIS ZONE. AS THESE FEATURES MOVE OVER
SOUTHERN ARIZONA TONIGHT THEY SHOULD PROVIDE ENOUGH DYNAMICS FOR
NOCTURNAL CONVECTION ALLOWING THUNDERSTORM DEVELOPMENT TO CONTINUE
THROUGH THE NIGHT.

FOR THE REMAINDER OF THE WEEK...MOISTURE REMAINS IN PLACE THROUGH
THE WEEKEND AS SOUTHEAST FLOW ALOFT CONTINUES OVER ARIZONA. THE HIGH
PRESSURE CENTER WILL BEGIN A JOURNEY EASTWARD ON SUNDAY AS A LOW
PRESSURE SYSTEM ENTERS THE PACIFIC NORTHWEST. THE MEDIUM RANGE
MODELS FORECAST THIS LOW TO BRING A DRIER SOUTHWEST FLOW TO ARIZONA
LATE ON MONDAY REDUCING THE AVAILABLE MOISTURE FOR THUNDERSTORM
DEVELOPMENT. ALTHOUGH THE STRENGTH OF THIS SYSTEM VARIES WITH THE
MODELS THEY ALL AGREE THAT A TROUGH WILL MOVE INTO THE WESTERN U.S.

&&

.AVIATION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
CONTINUE THIS AFTERNOON AND EVENING. THERE WILL BE A SLIGHT CHANCE
FOR THUNDERSTORMS OVERNIGHT AS WELL. CEILINGS OF BKN050-070CB AGL
ARE EXPECTED. OTHERWISE...EXPECT SKIES MAINLY SCT-BKN120 BKN-OVC250.
HEAVY DOWNPOURS MAY AFFECT TAF SITES. AVIATION DISCUSSION NOT
UPDATED FOR TAF AND TWEB AMENDMENTS.

&&

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

&&

EVANS
WEATHER.GOV/TUCSON

Hazardous weather outlook, Jul 31, 9:25 AM MST, 6 hours 37 minutes before

HAZARDOUS WEATHER OUTLOOK...CORRECTION
NATIONAL WEATHER SERVICE TUCSON AZ
925 AM MST TUE JUL 31 2007

AZZ019-029>035-010700-
NORTHERN GREENLEE COUNTY-SOUTHEAST PINAL COUNTY-
UPPER GILA RIVER VALLEY-WESTERN PIMA COUNTY-TOHONO OODHAM NATION-
TUCSON METRO/MARANA/GREEN VALLEY-SANTA CRUZ COUNTY-COCHISE COUNTY-
925 AM MST TUE JUL 31 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
ARIZONA AND SOUTHEAST ARIZONA.

.DAY ONE...TODAY AND TONIGHT

SOUTHEAST ARIZONA IS EXPECTED TO REMAIN IN A RATHER ACTIVE MONSOON
PATTERN TODAY AND TONIGHT WITH SCATTERED THUNDERSTORMS THIS
AFTERNOON AND EVENING. GIVEN THE EXCESSIVE RAINFALL ACROSS MUCH OF
THE AREA THE PAST SEVERAL DAYS IT WILL NOT TAKE MUCH ADDITIONAL
RAINFALL TO CAUSE MORE FLASH FLOODING AND SMALL STREAM FLOODING. IN
ADDITION TO POSSIBLE FLOODING...SOME OF THE STRONGER THUNDERSTORMS
WILL PRODUCE GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A CONTINUATION OF THE FAVORABLE MONSOON PATTERN IS EXPECTED INTO
THIS WEEKEND AS EASTERLY FLOW AROUND THE UPPER LEVEL HIGH TO OUR
NORTH CONTINUES. AS A RESULT...THE RISK FOR STRONG THUNDERSTORMS
WITH HEAVY RAIN AND FLASH FLOODING WILL CONTINUE.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

In the hours before

Local storm report, Jul 31, 2:47 PM MST, 1 hour 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
247 PM MST TUE JUL 31 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0246 PM     FLASH FLOOD      2 NNE TUCSON            32.26N 110.93W
07/31/2007                   PIMA               AZ   TRAINED SPOTTER

            STREET FLOODING AT 1ST AND GLENN AVENUES

&&

PYTLAK

Local storm report, Jul 31, 2:53 PM MST, 1 hour 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
253 PM MST TUE JUL 31 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0225 PM     TSTM WND GST     DAVIS-MONTHAN AIR FORCE 32.18N 110.87W
07/31/2007  E58 MPH          PIMA               AZ   TRAINED SPOTTER

&&

EVANS

Local storm report, Jul 31, 2:56 PM MST, 1 hour 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
256 PM MST TUE JUL 31 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0245 PM     FLASH FLOOD      HICKIWAN                32.36N 112.49W
07/31/2007                   PIMA               AZ   COUNTY OFFICIAL

            3 FT RISE ON HICKIWAN WASH IN ONE HOUR.

&&

PYTLAK

Local storm report, Jul 31, 3:10 PM MST, 52 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
310 PM MST TUE JUL 31 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0310 PM     FLASH FLOOD      TUCSON                  32.24N 110.94W
07/31/2007                   PIMA               AZ   BROADCAST MEDIA

            NUMEROUS STREETS FLOODED IN DOWNTOWN TUCSON

&&

PYTLAK

Local storm report, Jul 31, 3:37 PM MST, 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
337 PM MST TUE JUL 31 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0300 PM     FLASH FLOOD      SABINO CANYON           32.34N 110.81W
07/31/2007                   PIMA               AZ   PARK/FOREST SRVC

            3.5 FT RISE ON SABINO CREEK IN ONE HOUR

&&

PYTLAK

The office that day

Everything else NWS Tucson, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 30, 5:37 PM MST	Dust Storm Warning	TWC		2 hr
Jul 30, 7:58 PM MST	Areal Flood Advisory	TWC	Pima	92 min
Jul 30, 8:10 PM MST	Flash Flood Warning	TWC	Pima	95 min
Jul 30, 9:48 PM MST	Areal Flood Advisory	TWC	Cochise, Pima, Santa Cruz	117 min
Jul 31, 11:28 AM MST	Areal Flood Advisory	TWC	Pima	3 hr
Jul 31, 1:02 PM MST	Areal Flood Advisory	TWC	Pinal	118 min
Jul 31, 1:08 PM MST	Areal Flood Advisory	TWC	Pima	97 min
Jul 31, 1:47 PM MST	Flash Flood Warning	TWC	Pima	118 min
Jul 31, 2:14 PM MST	Severe Thunderstorm Warning	TWC	Pima	46 min
Jul 31, 2:19 PM MST	Flash Flood Warning	TWC	Pima	116 min
Jul 31, 2:33 PM MST	Areal Flood Warning	TWC	Pima	8 hr
Jul 31, 3:16 PM MST	Areal Flood Advisory	TWC	Pinal	89 min
Jul 31, 3:29 PM MST	Flash Flood Warning	TWC	Pima	3 hr
Jul 31, 3:43 PM MST	Areal Flood Advisory	TWC	Cochise, Pima, Santa Cruz	92 min
Jul 31, 3:52 PM MST	Flash Flood Warning	TWC	Graham	113 min

Nearby

Flash Flood Warnings in Arizona, 2007 Every flash flood warning in 2007

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.