Alert archive / Arizona / Flash Flood Warnings in 1991

Flash Flood Warning 2, NWS Tucson, AZ

September 1, 1991Pima County, Santa Cruz County, Arizona

NWS Tucson, AZ issued this flash flood warning at Sep 1, 1991, 4:40 PM MST for Pima County, Santa Cruz County, Arizona. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Sep 1, 1991, 4:40 PM MST (23:40 UTC)
Expired
Sep 1, 1991, 6:45 PM MST
In force
2 hr
Issued by
NWS Tucson, AZ
Area
Whole counties

Counties Pima County, AZ, Santa Cruz County, AZ

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 11.7 hours before the alert went out and 56 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 1991-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 128 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 12:00Z on 1991-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 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
128 J/kg
Mixed-layer CIN
-119 J/kg
Mixed-layer LCL
2199 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
-28 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 012340
FFWTUS
AZC019-023-020145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
FLASH FLOOD WARNING 
NATIONAL WEATHER SERVICE TUCSON AZ
440 PM MST SUN SEP 1 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING 
EFFECTIVE UNTIL 645 PM MST FOR PEOPLE IN THE FOLLOWING 
COUNTIES

   IN THE SOUTHEAST PART OF ARIZONA
      CENTRAL PIMA...WESTERN SANTA CRUZ

AT 420 PM MST TUCSON RADAR INDICATED PERSISTENT STRONG
THUNDERSTORMS ACROSS CENTRAL PIMA AND WESTERN SANTA CRUZ COUNTIES.
THESE STORMS APPEAR TO BE AFFECTING THE COMMUNITIES OF SELLS...
TOPAWA...SAN MIGUEL...SASABE...ARIVACA AND NOGALES.  THOUGH THESE
STORMS MAY NOT DIRECTLY BE OVER THE COMMUNITIES MENTIONED RUNOFF
FROM SURROUNDING MOUNTAINS COULD CAUSE FLOODING IN AREAS NOT
RECEIVING RAIN DIRECTLY.

STAY OUT OF WASHES AND LOW LYING AREAS.  FLASH FLOODS CAN OCCUR
WITH LITTLE OR NO ADVANCE WARNING.

IF YOU ARE IN THE WARNED COUNTY IN AN AREA SUBJECT TO FL1OODING
MOVE TO HIGHER GROUND.

DO NOT ATTEMPT TO DRIVE OVER ROADS COVERED BY FLOOD WATERS OR
ACROSS FLOODED HIGHWAY DIPS.

 NORDQUIST

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.

In the hours before

Special weather statement, Sep 1, 12:18 PM MST, 4 hours 22 minutes before
AZZ007-012300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
1217 PM MST SUN SEP 01 1991

...THUNDERSTORMS DEVELOPING IN SOUTHCENTRAL ARIZONA...

AT 1210 PM MST TUCSON WEATHER RADAR AND BUREAU OF LAND MANAGEMENT
LIGHTNING DETECTION EQUIPMENT INDICATED THUNDERSTORMS DEVELOPING IN
SOUTHCENTRAL ARIZONA.  AT THIS TIME THE STRONGEST STORMS ARE LOCATED
IN CENTRAL PIMA COUNTY ALONG STATE ROUTE 86 BETWEEN TUCSON AND AJO
AND JUST SOUTH OF INTERSTATE 8 BETWEEN CASA GRANDE AND GILA BEND.

SOME OF THESE STORMS ARE MOVING SLOWLY TO THE NORTH WHILE OTHERS
ARE NEARLY STATIONARY.

SINCE THESE STORMS SHOW LITTLE MOVEMENT.  LOCALIZED AREAS OF HEAVY
RAINFALL MAY OCCUR...POSSIBLY LEADING TO FLOODING OF NORMALLY DRY
WASHES AND ROADWAY DIPS.  STRONG GUSTY WINDS ACCOMPANIED BY AREAS OF
DENSE BLOWING DUST...AND NUMEROUS DEADLY CLOUD TO GROUND LIGHTNING
STRIKES ARE ALSO POSSIBLE.

THOSE TRAVELLING SHOULD BE AWARE OF RAPIDLY CHANGING CONDITIONS...
AND USE EXTRA CAUTION WHILE IN THE AFFECTED AREAS THE REMAINDER OF
THIS AFTERNOON AND EVENING.

GANSHEIMER/NWS TUS

Nearby

Flash Flood Warnings in Arizona, 1991Every flash flood warning in 1991

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.