Alert archive / Oklahoma / Flash Flood Warnings in 1990

Flash Flood Warning 51, NWS Norman, OK

September 21, 19904 counties in Oklahoma

NWS Norman, OK issued this flash flood warning at Sep 21, 1990, 12:19 AM CDT for 4 counties in Oklahoma. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Sep 21, 1990, 12:19 AM CDT (05:19 UTC)
Expired
Sep 21, 1990, 3:15 AM CDT
In force
3 hr
Issued by
NWS Norman, OK
Area
Whole counties

Counties Canadian County, OK, Cleveland County, OK, Lincoln County, OK, Oklahoma County, OK

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

Norman, OK (KOUN), launched 00:00Z, 5.3 hours before the alert went out and 31 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, Norman, OK at 00:00Z on 1990-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 308 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, Norman, OK at 00:00Z on 1990-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 square meters per square second.193958Sfc1 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
308 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
851 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
101 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 20, 11:46 PM CDT, 33 minutes before
OKZ0-011-015-016-210500-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
1130 PM CDT THU SEP 20 1990

...THUNDERSTORMS WITH VERY HEAVY RAIN AND GUSTY WINDS ARE MOVING
THROUGH CENTRAL OKLAHOMA...

AT 1130 PM AN AREA OF THUNDERSTORMS WITH VERY HEAVY RAIN AND GUSTY WINDS
EXTENDED FROM EASTERN CANADIAN AND NORTHEASTERN GRADY COUNTIES ACROSS
MOST OF OKLAHOMA COUNTY AND NORTHERN PORTIONS OF CLEVELAND AND MCCLAIN
COUNTIES. HEAVY RAINS HAVE BEEN REPORTED DURING THE PAST HOUR AT YUKON
MOORE MUSTANG AND THE OKLAHOMA CITY AREA ALONG WITH STREET FLOODING.

THE THUNDERSTORMS WILL CONTINUE TO MOVE NORTHEASTWARD AT 20 MPH AND WILL
SPREAD INTO LINCOLN AND NORTHERN POTTAWATOMIE COUNTIES! DURING THE NEXT
HOUR. MOTORISTS SHOULD BE VERY CAUTIOUS AND BE ALERT FOR POOR VISIBILITIES
AND FLOODED STREETS WHILE DRIVING THROUGH THIS AREA DURING THE NEXT 1 TO
2 HOURS. BRIEF STRONG AND GUSTY WINDS MAY ALSO ACCOMPANY THESE STORMS.

The office that day

Everything else NWS Norman, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 21, 12:19 AM CDTFlash Flood WarningOUNGrady3 hr
Sep 21, 2:27 AM CDTFlash Flood WarningOUNCoal, Pontotoc4 hr

Nearby

Flash Flood Warnings in Oklahoma, 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.