Alert archive / Arizona / Flash Flood Warnings in 1990

Flash Flood Warning 5, NWS Tucson, AZ

July 20, 1990Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 20, 1990, 5:45 AM MST for Pima County, Arizona. It was in force for 75 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1990, 5:45 AM MST (12:45 UTC)
Expired
Jul 20, 1990, 7:00 AM MST
In force
75 min
Issued by
NWS Tucson, AZ
Area
Whole counties

County Pima County, AZ

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 0.8 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 1990-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 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 1990-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -88 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1260 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
-88 m²/s²
0-3 km storm-relative helicity
-72 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 201245
FFWTUS
AZC019-201400-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
FLASH FLOOD WARNING 
NATIONAL WEATHER SERVICE TUCSON AZ
545 AM MST FRI JUL 20 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING 
EFFECTIVE UNTIL 700 AM MST FOR PEOPLE IN THE FOLLOWING COUNTY

   IN THE SOUTH CENTRAL PART OF ARIZONA
      EASTERN PIMA

AT 535 AM REPORTS FROM MULTIPLE SOURCES INCLUDING THE PIMA COUNTY
SHERIFFS OFFICE AND PIMA COUNTY FLOOD CONTROL GAUGES INDICATED THAT
MANY ROADWAYS IN THE TUCSON METRO AREA ARE BEING FLOODED.  WITH THE
MORNING RUSH HOUR FAST APPROACHING MOTORISTS ARE ASKED TO BE
EXTREMELY CAREFUL THIS MORNING.

DO NOT ATTEMPT TO DRIVE OVER ROADS COVERECD 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, Jul 20, 2:46 AM MST, 2 hours 59 minutes before
AZZ009-010-201230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
240 PM MST FRI JUL 20 1990

...FLASH FLOOD WATCH FOR SOUTHEAST ARIZONA...

AT 230 AM VISUAL OBSERVATIONS AND RADAR INDICATED STRONG THUNDERSTORMS
MOVING INTO THE TUCSON METRO AREA.  PIMA COUNTY FLOOD CONTROL GAUGES
DO INDICATE PERIODS OF HEAVY RAIN WITH THESE STORMS AND FREQUENT
CLOUD TO GROUND LIGHTNING IS OCCURRING.

PERSONS IN THE AREA OF THE THUNDERSTORMS SHOULD USE EXTREME CAUTION.
STAY OUT OF NORMALLY DRY WASHES...CREEKS...AND ROADWAY DIPS...
ESPECIALLY THE TANQUE VERDE AND PANTANO CREEKS AS WELL AS THE
RILLITO RIVER.

NORDQUIST

Nearby

Flash Flood Warnings in Arizona, 1990Every flash flood warning in 1990

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.