Alert archive / Arizona / Flash Flood Warnings in 1997

Flash Flood Warning 37, NWS Tucson, AZ

August 21, 1997Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 21, 1997, 3:51 PM MST for Pima County, Arizona. It was in force for 59 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 21, 1997, 3:51 PM MST (22:51 UTC)
Expired
Aug 21, 1997, 4:50 PM MST
In force
59 min
Issued by
NWS Tucson, AZ
Area
Whole counties

County Pima County, AZ

The radar

The Tucson radar (KEMX), 112 km from the middle of the area, began a volume at 22:52 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.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 10.9 hours before the alert went out and 84 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-pSkew-T log-p diagram, Tuscon, AZ at 12:00Z on 1997-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 123 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 12:00Z on 1997-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
123 J/kg
Mixed-layer CIN
-263 J/kg
Mixed-layer LCL
2231 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
81 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 
TTAA00 KTUS 212253
FFWTUS
AZC019-212350-

BULLETIN
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
351 PM MST THU AUG 21 1997

THE NATIONAL WEATHER SERVICE IN TUCSON AZ HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 450 PM MST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN SOUTHERN ARIZONA

   ...EASTERN PIMA COUNTY INCLUDING THE EASTERN PORTION OF THE
TUCON METRO AREA...
 
AT 350 PM TUCSON DOPPLER RADAR INDICATED A STRONG THUNDERSTORM WITH
HEAVY RAIN IN THE FAR EASTERN PORTION OF THE TUCSON METRO
AREA...NEAR THE SAGUARO NATIONAL MONUMENT. THIS THUNDERSTORM HAS
RAINFALL RATES IN EXCESS OF 1 INCH PER HOUR. HEAVY RAIN IS ALSO
FALLING IN THE VAIL AND COLOSSAL CAVE AREAS.

MOTORISTS ARE URGED TO USE CAUTION jAS WASHES AND DIPS WILL
RAPIDLY FILL WITH WATER. DON'T DRIVE INTO AREAS WHERE WATER COVERS
THE ROAD!
 
HOLBROOK

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 Aug 21, 2:30 PM MST, 1 hour 21 minutes earlier.

Area forecast discussion, Aug 21, 2:30 PM MST, 1 hour 21 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST THU AUG 21 1997

TEMPS HEATG UP NICELY THIS AFTN. STG TO SVR TS ALRDY STARTG TO
FIRE IN THE FAVORABLE AREAS. XPCT AN ACTIVE LATE AFTN AND EVE FOR
SE AZ. 18Z TUS SNDG CONTS TO SHOW A CAPE ARND 1400 J/KG SO ONLY
NEED OUTFLOW BNDRIES TO GET THINGS GOING IN THE LWR VLYS. STG
VERTICAL SHEAR EVIDENT IN THIS MRNGS SNDGS MAKE SVR DWN BURST
WNDS PSBL WITH THE STGR CELLS. COORD WITH SPC CONCERNG A WK
INVERTED TROF MOVG INTO SRN AZ THIS EVE. THIS FEATURE MAY BE THE
TRIGGER FOR LARGE OUTBREAK TNGT. WATCH BOX HAS BEEN ISSUED BY SPC
THRU 22/04Z.

H5 HI RMNS IN A FAVORABLE POSTN FRI/SAT AS OTHER INVERTED TROFS
MOV INTO THE RGN FM SONORA. WL HAVE TO WATCH FOR PSBL SURGES THRU
SAT. FRI MAY END UP BEING A DOWN DAY FOR TS AFT TNGTS ACTIVITY.
FOR NOW WL GO WITH THE USUAL MONSOON FCST.

POTENT TROF MOVG THRU THE PAC NW THIS WEEKEND TO FLATTEN RDG AND
PUSH HI CNTR TO FAR SE AZ. RDG TO REBOUND BY DAY 5. AGREE WITH
PHX THAT BROADBUSH FCST THE BEST WAY TO GO. TUS 5343. OKULSKI

TUS...SEVERE THUNDERSTORM WATCH FOR ZNS 26>30 THRU 22/04Z.

In the hours before

Special weather statement, Aug 21, 11:41 AM MST, 4 hours 10 minutes before
AZZ019-026>030-212300-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1145 AM MST THU AUG 21 1997...THIS PRODUCT IS NOT UPDATED

                AREAL    PROBABILITY   RAIN GREATER THAN   STORM
              COVERAGE    OF SEVERE     1.00       2.00    MOTION

COCHISE          50          45          70         40      W 10
GRAHAM           45          40          40         25      W 10
GREENLEE         40          35          30         15     SW 10
TUCSON/ERN PIMA  40          40          50         30      W 10
TOHONO OODHAM   30          40          40         25      W 10
WESTERN PIMA     20          30          30         20      W 10
SOUTHEAST PINAL  30          35          50         30      W 10
SANTA CRUZ       50          45          75         50      W 10

SYNOPSIS...MOISTURE WILL CONTINUE TO INCREASE OVER SOUTHERN
ARIZONA TODAY. THE AIR MASS WILL BECOME VERY MOIST AND UNSTABLE
BY THE LATE AFTERNOON WITH SCATTERED STRONG THUNDERSTORM
DEVELOPMENT OVER MUCH OF SOUTHEAST ARIZONA EXPECTED. SOME OF THE
STORMS MAY CONTINUE UNTIL AFTER MIDNIGHT TONIGHT. THE VERY MOIST
AND UNSTABLE AIR MASS WILL MAKE HEAVY RAINFALL LIKELY...AND
SEVERE WIND POSSIBLE.
*****************************************************************
KEY...
AREAL COVERAGE - PERCENT OF COUNTY OR AREA THAT WILL EXPERIENCE
                  THUNDERSTORMS
PROB OF SEVERE - THE PROBABILITY THAT ANY ONE OF THE STORMS WILL
                  REACH SEVERE LEVELS (DAMAGING WIND AND/OR
                  LARGE HAIL)
RAIN GRTR THAN - THE PROBABILITY THAT ANY ONE OF THE STORMS WILL
                  PRODUCE RAIN EXCEEDING 1 INCH OR 2 INCHES IN
                  ANY LOCATION
STORM MOTION   - GENERAL DIRECTION TO WHICH THE STORMS WILL
                  LIKELY MOVE AND SPEED IN MPH

NOTE...
VALID TIME IS FROM 12 NOON TO 12 MIDNIGHT OF THE DAY OF ISSUANCE

THIS PRODUCT IS NOT TO BE USED IN PLACE OF SEVERE THUNDERSTORM OR
FLASH FLOOD WARNINGS OR WATCHES. THIS PRODUCT IS ONLY USED FOR
OUTLOOK PURPOSES.

END/OKULSKI

Nearby

Flash Flood Warnings in Arizona, 1997Every flash flood warning in 1997

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.