Alert archive / Arizona / Flash Flood Warnings in 1990

Flash Flood Warning 22, NWS Phoenix, AZ

July 21, 1990Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 21, 1990, 8:56 PM MST for Maricopa County, Arizona. It was in force for 79 min.

The area

The counties it named.

The facts

Issued
Jul 21, 1990, 8:56 PM MST (03:56 UTC)
Expired
Jul 21, 1990, 10:15 PM MST
In force
79 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Maricopa 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 00:00Z, 3.9 hours before the alert went out and 198 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 00:00Z on 1990-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1254 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 00:00Z on 1990-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
1254 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
2112 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
16 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 KPHX 220356
FFWPHX
AZC013-220600-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
856 PM MST SAT JUL 21 1990
 
THE NATIONAL WEATHER SERVICE IN PHOENIX ARIZONA HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 1100 PM MST
FOR THE FOLLOWING LOCATIONS......
 
IN SOUTH CENTRAL ARIZONA
 
   ...NORTHERN MARICOPA COUNTY
 
AT 845 PM MST THE LATEST PHOENIX WEATHER RADAR WAS DETECTING
THUNDERSTORMS WITH VERY HEAVY RAIN OVER MUCH OF NORTHERN MARICOPA
COUNTY. THE HEAVIEST RAINFALL WAS APPARANTLY OCCURING BETWEEN
AGUILA AND MORRISTOWN AS WELL AS NEAR BEARDSLEY. THE THUNDERSTORMS
WERE MOVING SOUTH AT ABOUT 10 TO 15 MPH.
 
MANY ROADS IN NORTHERN MARICOPA COUNTY...INCLUDING THE GREATER
PHOENIX AREA ARE FLOODED. IN ADDITION...THE PREVIOUS THUNDERSTORMS
HAVE CAUSED CONSIDERABLE DAMAGE WITH MUCH DEBRIS COVERING MANY ROAD.
THEREFORE...TRAVELLING THIS EVENING IS DISCOURAGED THROUGHOUT
NORTHERN MARICOPA COUNTY.
 
FLASH FLOODING IS ALREADY HAPPENING OR ABOUT TO HAPPEN. MOVE AWAY
FROM STREAMS OR WASHES. HEAD FOR HIGHER GROUND. ON THE HIGHWAY...SLOW
DOWN AND KEEP A SHARP LOOKOUT AHEAD FOR FLOODING.
 
URBAN FLOODING IS OVERFLOW OF CITY STREETS AND DRAINAGE SYSTEMS...
ENOUGH TO FLOOD RESIDENCES AND BUSINESSES AND CLOSE CITY STREETS.
POSTPONE ANY UNNECESSARY DRIVING UNTIL THE STORM IS OVER.
 
MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES. DONT TRY TO CROSS
FLOODING WASHES OR STREAMS. NEVER DRIVE ONTOW A BRIDGE COVERED BY
WATER. STAY OFF FLOODED CITY STREETS. OUTSIDE THE CITY...STAY ON MAIN
HIGHWAYS. AVOID SECONDARY ROADS AND FARM ROADS...ESPECIALLY AT NIGHT.

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 21, 3:24 PM MST, 5 hours 32 minutes before
AZC005-009-025-220030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
323 PM MST SAT JUL 21 1990

AT 315 PM MST THERE WERE WIDELY SCATTERED THUNDERSTORMS RUMBLING
THROUGHOUT MUCH OF THE CENTRAL MOUNTAIN AREAS OF ARIZONA. THESE
THUNDERSTORMS WERE IN A BROKEN LINE FROM CENTRAL YAVAPAI COUNTY EAST
SOUTHEASTWARD THROUGH COCONINO COUNTY AND ON INTO NORTHERN GRAHAM
COUNTY.

LATEST RADAR REPORTS SHOWED THAT THE THUNDERSTORMS WITH THE HEAVIEST
RAINS WERE LOCATED NEAR MAYER...THE KOHLS RANCH AREA OF THE RIM AND
ANOTHER OVER EXTREME NORTHERN GRAHAM COUNTY NORTHEAST OF ASH CREEK.

MOTORISTS IN THESE AREAS SHOULD AVOID TRAVELLING THROUGH LOW SPOTS AND
HIGHWAY DIPS WITH WATlER RUNNING THROUGH THEM. IN ADDITION...HIKERS
SHOULD STAY OUT OF NARROW STEEP WALLED CANYONS IF THUNDERSTORMS ARE IN
THE AREA.

THE SHOWERS AND THUNDERSTORMS WERE GENERALLY MOVING SOUTHEASTWARD AT
ABOUT 10 TO 15 MPH.

ESTLE
Special weather statement, Jul 21, 4:27 PM MST, 4 hours 29 minutes before
AZZ004-005-006-008-010-220130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
425 PM MST SAT JUL 21 1990

AT 410 PM PHOENIX WEATHER RADAR CONTINUED TO SHOW DEVELOPING
THUNDERSTORMS FROM YAVAPAI COUNTY EAST SOUTHEAST ACROSS GILA COUNTY
AND ON INTO EXTREME SOUTHERN APACHE...NAVAJO AND NORTHERN GRAHAM COUNT

THE HEAVIEST RAIN WAS OCCURING ALONG THE RIM JUST WEST OF PINE...IN
EXTREME SOUTHERN APACHE AND NAVAJO COUNTIES NORTH OF ASH CREEK...AND
SOUTHWEST OF CIBECUE.

THE THUNDERSTORMS WERE BEGINNING TO SHOW SIGNS OF MOVING MORE TOWARDS
THE SOUTH SOUTHWEST AT ABOUT 15 TO 20 MPH.

SOME OF THE RAIN FROM THESE THUNDERSTORMS COULD CAUSE WASHES TO BEGIN
RUNNING SOMEWHAT. MOTORISTS SHOULD THEREFORE PROCEED WITH CAUTION AND
SHOULD AVOID CROSSING FLOODED ROADWAY DIPS.

THE THUNDERSTORMS...AS THEY CONTINUE TO DEVELOP AND MOVE SOUTHWARD
COULD EVENTUALLY AFFECT THE EASTERN PORTIONS OF THE PHOENIX METRO
AREA LATER THIS SATURDAY EVENING. THE MOST LIKELY EVENT WOULD BE LOTS
OF WIND AND BLOWING DUST. IF YOU NEED TO TRAVEL AROUND THE PHOENIX ARE
WELL AS ALL OF THE EASTERN RIM AND THE SOUTHEAST THIS EVENING...IT WOU
A GOOD IDEA TO KEEP A CLOSE CHECK ON THE LATEST WEATHER DEVELOPMENTS.

ESTLE
Special weather statement, Jul 21, 4:31 PM MST, 4 hours 25 minutes before
AZZ004-005-006-008-010-220130-

SPECIAL WEATHER STATEMENT...CORRECTION
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
425 PM MST SAT JUL 21 1990

AT 410 PM PHOENIX WEATHER RADAR CONTINUED TO SHOW DEVELOPING
THUNDERSTORMS FROM YAVAPAI COUNTY EAST SOUTHEAST ACROSS GILA COUNTY
AND ON INTO EXTREME SOUTHERN APACHE...NAVAJO AND NORTHERN GRAHAM
COUNTIES.

THE HEAVIEST RAIN WAS OCCURING ALONG THE RIM JUST WEST OF PINE...IN
EXTREME SOUTHERN APACHE AND NAVAJO COUNTIES NORTH OF ASH CREEK...AND
SOUTHWEST OF CIBECUE.

THE THUNDERSTORMS WERE BEGINNING TO SHOW SIGNS OF MOVING MORE TOWARDS
THE SOUTH SOUTHWEST AT ABOUT 15 TO 20 MPH.

SOME OF THE RAIN FROM THESE THUNDERSTORMS COULD CAUSE WASHES TO BEGIN
RUNNING SOMEWHAT. MOTORISTS SHOULD THEREFORE PROCEED WITH CAUTION AND
SHOULD AVOID CROSSING FLOODED ROADWAY DIPS.

THE THUNDERSTORMS...AS THEY CONTINUE TO DEVELOP AND MOVE SOUTHWARD
COULD EVENTUALLY AFFECT THE EASTERN PORTIONS OF THE PHOENIX METRO
AREA LATER THIS SATURDAY EVENING. THE MOST LIKELY EVENT WOULD BE LOTS
OF WIND AND BLOWING DUST. IF YOU NEED TO TRAVEL AROUND THE PHOENIX
AREA AS WELL AS ALL OF THE EASTERN RIM AND THE SOUTHEAST THIS EVENING.
IT WOULD BE A GOOD IDEA TO KEEP A CLOSE CHECK ON THE LATEST WEATHER
DEVELOPMENTS.

ESTLE
Special weather statement, Jul 21, 5:23 PM MST, 3 hours 33 minutes before
AZC007-009-013-220215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
519 PM MST SAT JUL 21 1990

AT 510 PM MST WEATHER SERVICE RADAR SHOWED SEVERAL LARGE THUNDERSTORMS
IN THE VICNITY OF THE SALT AND VERDE RECREATIONAL LAKES. THE STRONGEST
STORM WAS JUST NORTHEAST OF BARTLETT RESERVOIR AND THIS EXTENDED WEST
TO NEAR THE TOWN OF CAREFREE. ANOTHER THUNDERSTORM WAS NEAR ROOSEVELT
LAKE. THESE STORMS WERE MOVING SOUTH SOUTHWESTWARD AT ABOUT 15 TO 20
MPH.

VERY HEAVY RAIN IS LIKELY WITH THESE THUNDERSTORMS...ALONG WITH STRONG
WINDS. BOATERS OUT ON THE LAKES SHOULD THINK ABOUT COMING ASHORE AND
TAKING COVER UNTIL THE STORM PASSES. THE THUNDERSTORM ACTIVITY SHOULD
MOVE SOUTH OF THE RECREATIONAL LAKES BY ABOUT 630 OR 7 PM MST.

FURTHER EAST...ANOTHER LARGE THUNDERSTORM WAS OVER FAR EASTERN GILA
COUNTY SOUTH OF WHITE RIVER. THIS THUNDERSTORM IS LIKELY GIVING VERY
HEAVY RAINFALL IN THE UPPER SALT RIVER CANYON. MOTORISTS SHOULD AVOID
DRIVING THROUGH ANY FLOODED HIGHWAY DIPS THAT MAY BE ENCOUNTERED.

ESTLE

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.