Alert archive / Arizona / Flash Flood Warnings in 1990

Flash Flood Warning 42, NWS Phoenix, AZ

August 12, 1990Mohave County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 12, 1990, 4:07 AM MST for Mohave County, Arizona. It was in force for 95 min.

The area

The counties it named.

The facts

Issued
Aug 12, 1990, 4:07 AM MST (11:07 UTC)
Expired
Aug 12, 1990, 5:42 AM MST
In force
95 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Mohave 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

Mercury/Desert R, NV (KDRA), launched 00:00Z, 11.1 hours before the alert went out and 226 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, Mercury/Desert R, NV at 00:00Z on 1990-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Mercury/Desert R, NV at 00:00Z on 1990-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 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
0 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
-25 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 121118
FFWPHX
AZC015-121415-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
407 AM MST SUN AUG 12 1990
 
THE NATIONAL WEATHER SERVICE IN PHOENIX ARIZONA HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  700 AM MST
FOR THE FOLLOWING LOCATIONS......
 
IN NORTHWEST ARIZONA
 
   ...SOUTHWESTERN MOHAVE COUNTY... WHICH INCLUDES THE HIGHWAYS
CONNECTING BULLHEAD CITY.
 
A FEW THUNDERSTORMS WHICH DEVELOPED OVER SOUTHERN NEVADA AND NORTHWEST
ARIZONA MERGED OVER BULLHEAD CITY AFTER 330 AM.   VERY HEAVY RAIN LEAD
TO FLOODING OF WASHES AND SOME CITY STREETS.  HIGHWAY 95 ACROSS THE
SOUTHERN END OF TOWN WAS CLOSED IN 3 LOCATIONS DUE TO HEAVY
RUNOFF.
 
HEAVY RAIN WILL PERSIST AROUND THE BULLHEAD CITY AREA UNTIL 4AM.
WASHES AND URBAN FLOODING WILL TAKE AN HOUR OR SO TO SUBSIDE.
 
MOTORISTS PLANNING TRAVEL IN AND OUT OF BULLHEAD CITY SHOULD POSTPONE
PLANS FOR A FEW HOURS UNTIL THE STORM IS OVER.
 
THE FLASH FLOOD WARNING FOR THE BULLHEAD CITY AREA IS IN EFFECT UNTIL
7 AM.
 
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 ONTO A BRIDGE COVERED BY
WATER. STAY OFF FLOODED CITY STREETS. OUTSIDE THE CITY...STAY ON MAIN
HIGHWAYS. AVOID SECONDnARY ROADS AND FARM ROADS...ESPECIALLY AT NIGHT.
 
VASQUEZ

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, Aug 12, 4:02 AM MST, 5 minutes before
AZZALL-121300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
400 PM MST SUN AUG 12 1990

... NEW THUNDERSTORMS DEVELOPING IN THE BULLHEAD CITY AREA...

A FEW THUNDERSTORMS RANDOMLY DEVELOPED OVER SOUTHERN NEVADA AND
FAR NORTHWEST ARIZONA THROUGH THE NIGHT.  THUNDERSTORMS OVER THESE
AREAS HAVE BEEN PRODUCING BRIEF HEAVY RAINS.

AFTER 330 AM A NEW AREA OF THUNDERSTORMS DEVELOPED IN THE BULLHEAD
CITY AREA.  THESE STORMS WERE DRIFTING SLOWLY SOUTHWARD AND EXPECTED
TO PRODUCE BRIEF HEAVY RAINS AND STRONG WINDS.

THESE THUNDERSTORMS ARE EXPECTED TO PERSIST FOR AN HOUR OR SO THEN
DISSIPATE.  THE AIRMASS OVER NORTHWEST ARIZONA IS VERY MOIST AND
UNSTABLE AND THUNDERSTORM REDEeVELOPMENT CAN TAKE PLACE AT ANYTIME.

VASQUEZ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 6:19 PM MSTFlash Flood WarningPSRYuma116 min
Aug 11, 6:19 PM MSTSevere Thunderstorm WarningPSRYuma116 min
Aug 11, 6:26 PM MSTFlash Flood WarningPSRMaricopa64 min
Aug 11, 6:26 PM MSTSevere Thunderstorm WarningPSRMaricopa64 min
Aug 11, 6:55 PM MSTFlash Flood WarningPSRLa Paz2 hr
Aug 11, 6:55 PM MSTSevere Thunderstorm WarningPSRLa Paz2 hr
Aug 11, 7:08 PM MSTFlash Flood WarningPSRYuma2 hr
Aug 11, 7:08 PM MSTSevere Thunderstorm WarningPSRYuma2 hr
Aug 11, 7:27 PM MSTFlash Flood WarningPSRMaricopa63 min
Aug 11, 7:27 PM MSTSevere Thunderstorm WarningPSRMaricopa63 min
Aug 11, 8:23 PM MSTFlash Flood WarningPSRMaricopa67 min
Aug 11, 8:23 PM MSTSevere Thunderstorm WarningPSRMaricopa67 min
Aug 11, 9:15 PM MSTSevere Thunderstorm WarningPSRLa Paz60 min

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.