Alert archive / Arizona / Flash Flood Warnings in 1997

Flash Flood Warning 58, NWS Tucson, AZ

September 21, 1997Cochise County, Graham County, Arizona

NWS Tucson, AZ issued this flash flood warning at Sep 21, 1997, 2:28 PM MST for Cochise County, Graham County, Arizona. It was in force for 62 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: Sep 21, 1997, 2:28 PM MST (21:28 UTC)
Expired: Sep 21, 1997, 3:30 PM MST
In force: 62 min
Issued by: NWS Tucson, AZ
Area: Whole counties

Counties Cochise County, AZ, Graham County, AZ

The radar

The Tucson radar (KEMX), 95 km from the middle of the area, began a volume at 21:31 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, 9.5 hours before the alert went out and 105 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: 393 J/kg
Mixed-layer CIN: -206 J/kg
Mixed-layer LCL: 1697 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 113 m²/s²
0-3 km storm-relative helicity: 193 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KTUS 212135 COR
FFWTUS
AZC003-009-212230-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING...CORRECTED TIME
NATIONAL WEATHER SERVICE TUCSON AZ
228 PM MST SUN SEP 21 1997

THE NATIONAL WEATHER SERVICE IN TUCSON AZ HAS EXTENDED THE
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING EFFECTIVE UNTIL 330 PM
MST AND EXPENDED TO INCLUDE SOUTHWESTERN GRAHAM COUNTY.
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN SOUTHEASTERN ARIZONA

   ...WESTERN COCHISE COUNTY
   ...SOUTHWESTERN GRAHAM COUNTY

AT 228 PM MST...DOPPLER RADAR INDICATED A LINE SEVERE THUNDERSTORM
WITH EXTREMELY HEAVY RAINFALL EXTENDING FROM SOUTHWEST GRAHAM COUNTY
TO THE MEXICAN BORDER. THE STRONGER STORMS IN THIS LINE ARE CAPABLE
OF PRODUCING VERY LARGE HAIL AND RAINFALL RATES IN EXCESS OF TWO
INCHES PER HOUR. STORM MOVEMENT WAS TO THE NORTHEAST AT 20 MPH.

&

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 Sep 21, 2:21 PM MST, 7 minutes earlier.

Area forecast discussion, Sep 21, 2:21 PM MST, 7 minutes before

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST SUN SEP 21 1997

MON...UPPER HIGH MOVES TO SE WY. WITH W-SWLY FLOW MID-UPPER LEVELS
OVER SERN AZ TO DRY CONSIDERABLY. WATER VAPOR DOES SHOW LOTS OF DRY
AIR UPSTREAM.  BUT 850 MB DEW POINTS STILL IN THE 10-14 DEGREE C
RANGE FROM TUS EWD. WILL SHOW ZERO POPS IN THE WEST...INCREASING TO
SCATTERED IN ERN ZONES. HURRICANE NORA SHOULD BE HOLDING ITS
INTENSITY AND CROSSING NORTH OF THE 20N LINE.
TUE...HURRICANE NORA FORECAST TO CROSS THE SRN TIP OF BAJA WITH
DECREASING STRENGTH. THE DEEPENING TROUGH FORECAST BY THE ETA LENDS
MORE CONFIDENCE TO THE NORTHWARD TRACK. MAIN MOISTURE FIELD FROM NORA
FORECAST TO STILL BE SOUTH OF ARIZONA. THE AVN IS EVEN DRYING OUT THE
LOW LEVELS.  WILL GO WITH ISOLATED TSTMS.
TUS 3320.

TUS...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 21, 2:08 AM MST	Severe Thunderstorm Warning	TWC	Pima	42 min
Sep 21, 4:03 AM MST	Severe Thunderstorm Warning	TWC	Pima, Pinal	67 min
Sep 21, 4:39 AM MST	Severe Thunderstorm Warning	TWC	Graham	61 min
Sep 21, 7:35 AM MST	Severe Thunderstorm Warning	TWC	Cochise, Pima	30 min
Sep 21, 12:56 PM MST	Flash Flood Warning	TWC	Cochise	94 min
Sep 21, 12:56 PM MST	Severe Thunderstorm Warning	TWC	Cochise	94 min
Sep 21, 2:16 PM MST	Flash Flood Warning	TWC	Cochise	64 min
Sep 21, 2:16 PM MST	Severe Thunderstorm Warning	TWC	Cochise	64 min
Sep 21, 2:28 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Graham	62 min
Sep 21, 3:33 PM MST	Flash Flood Warning	TWC	Cochise	62 min

Nearby

Flash Flood Warnings in Arizona, 1997 Every 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.