Alert archive / Oklahoma / Flash Flood Warnings in 1990

Flash Flood Warning 45, NWS Norman, OK

May 19, 1990Oklahoma County, Oklahoma

NWS Norman, OK issued this flash flood warning at May 19, 1990, 11:52 PM CDT for Oklahoma County, Oklahoma. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
May 19, 1990, 11:52 PM CDT (04:52 UTC)
Expired
May 20, 1990, 3:00 AM CDT
In force
3 hr
Issued by
NWS Norman, OK
Area
Whole counties

County 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, 4.9 hours before the alert went out and 37 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 1990-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3426 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 1990-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
3426 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1439 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.5
Supercell composite
5.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KOKC 200455 COR
FFWOKC
OKC109-200800-

BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
1152 PM CDT SAT MAY 19 1990

THE NATIONAL WEATHER SERVICE IN OKLAHOMA CITY HAS EXTENDED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  300 AM CDT
FOR THE FOLLOWING OKLAHOMA LOCATIONS...

IN CENTRAL OKLAHOMA

   ...OKLAHOMA COUNTY

AT 1152 PM RADAR CONTINUED TO INDICATE THUNDERSTORM DEVELOPMENT ACROSS
OKLAHOMA COUNTY. INDIVIDUAL THUNDERSTORMS WERE MOVING SLOWLY TOWARD
THE EAST. RAINFALL AMOUNTS OF 6 TO 8 INCHES HAVE OCCURRED ACROSS
PORTIONS OF OKLAHOMA COUNTY WITH REPORTS OF HOMES THREATENED BY RISING
WATER AND MANY ROADS CLOSED. VERY HEAVY RAINS WILL CONTINUE OVER THE
WARNING AREA FOR THE NEXT ONE TO TWO HOURS...FURTHER AGGRAVATING THE
FLOODING.


BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DANGERS OF FLOODS AND FLASH FLOODS.  IF FLASH FLOODING IS
OBSERVED...ACT QUICKLY.  MOVE UP TO ESCAPE FLOOD WEATERS.  DO
NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

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, May 19, 7:08 PM CDT, 4 hours 44 minutes before
OKZ016-200130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
708 PM CDT SAT MAY 19 1990

...STRONG THUNDERSTORMS DEVELOPING OVER THE OKLAHOMA CITY METRO AREA...

AT 705 PM RADAR INDICATED DEVELOPING THUNDERSTORMS OVER CLEVELAND COUNTY
IN THE VICINITY OF NORTH NORMAN AND MOORE. THESE STORMS HAVE DEVELOPED
RAPIDLY AND WERE MOVING EAST-NORTHEAST AT 20 MPH. HAIL AND STRONG
WINDS ARE LIKELY.  BOATERS ON LAKE THUNDERBIRD AND LAKE DRAPER SHOULD
REMAIN ALERT TO THE APPROACH OF THESE THUNDERSTORMS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT FOR THE METRO AREA.
AND THIS HAS SERVED TO LIMIT THE AMOUNT OF CONVERGENCE ALONG THE
FRONT AND OUTFLOW BOUNDARY. AS AFTERNOON HEATING CONTINUES AND
TEMPERATURES RISE WELL INTO THE 80S THUNDERSTORMS ARE EXPECTED TO
DEVELOP IN THE MODERATE RISK AREA AND INTENSIFY RAPIDLY TO SEVERE
LEVELS. THE THUNDERSTORMS WILL THEN MOVE NORTHEAST.

THE PRIMARY THREAT FROM THUNDERSTORMS THIS AFTERNOON WILL BE
LARGE HAIL. THE AMOUNT OF INSTABILITY PRESENT THIS AFTERNOON
SUGGESTS THAT SOME THUNDERSTORMS MAY PRODUCE BASEBALL-SIZED HAIL.
ISOLATED TORNADOES ARE ALSO POSSIBLE.

LAW ENFORCEMENT AND SPOTTER ORGANIZATIONS IN THE MODERATE RISK
ASREA SHOULD BE PREPARED FOR ACTIVATION AT ANY TIME THIS AFTERNOON.
Special weather statement, May 19, 7:11 PM CDT, 4 hours 41 minutes before
OKZ016-200130-

SPECIAL WEATHER STATEMENT...CORRECTION
NATIONAL WEATHER SERVICE OKLAHOMA CITY OK
708 PM CDT SAT MAY 19 1990

...STRONG THUNDERSTORMS DEVELOPING OVER THE OKLAHOMA CITY METRO AREA...

AT 705 PM RADAR INDICATED DEVELOPING THUNDERSTORMS OVER CLEVELAND COUNTY
IN THE VICINITY OF NORTH NORMAN AND MOORE. THESE STORMS HAVE DEVELOPED
RAPIDLY AND WERE MOVING EAST-NORTHEAST AT 20 MPH. HAIL AND STRONG
WINDS ARE LIKELY.  BOATERS ON LAKE THUNDWERBIRD AND LAKE DRAPER SHOULD
REMAIN ALERT TO THE APPROACH OF THESE THUNDERSTORMS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT FOR THE METRO AREA.
Special weather statement, May 19, 8:16 PM CDT, 3 hours 36 minutes before
TXZ020-200200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WICHITA FALLS TX
815 PM CDT SAT MAY 19 1990

...ACTIVE WEATHER REMAINS NORTH OF THE RED RIVER...

A STATIONARY FRONTAL BOUNDARY CUT THROUGH OKLAHOMA FROM TULSA TO NEAR
OKLAHOMA CITY TO SOUTHWEST OKLAHOMA.

THE DRY LINE/DEW POINT LINE THAT WAS JUST WEST OF WICHITA FALLS
AROUND 5PM HAD RETREATED TO WEST OF CHILDRESS AT SUNSET.

SEVERE THUNDERSTORMS WERE OCCURRING IN THE OKLAHOMA CITY AREA AND
EXTENDED NORTHEAST. MOVEMENT APPEARS TO BE SLOWLY TOWARDS THE NORTH.

A TORNADO WATCH REMAINS IN EFFECT FOR MUCH OF SOUTH CENTRAL...
CENTRAL AND EASTERN OKLAHOMA UNTIL MIDNIGHT.

LOCALLY... THE THREAT OF THUNDERSTORM DEVELOPMENT THIS NEVENING
APPEARS TO BE DIMINISHING.

AREA RESIDENTS SHOULD EXPECT THE NEXT GOOD CHANCE FOR THUNDERSTORMS
TO BE ON SUNDAY. ANOTHER HOT DAY IS FORECAST WITH THE DRY LINE/DEW
POINT LINE FORECAST TO MOVE EAST THROUGH THE REGION ON SUNDAY.

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 7:14 PM CDTSevere Thunderstorm WarningOUNLincoln, Payne46 min
May 19, 7:22 PM CDTSevere Thunderstorm WarningOUNCleveland, Oklahoma53 min
May 19, 7:32 PM CDTSevere Thunderstorm WarningOUNLincoln, Pottawatomie43 min
May 19, 7:35 PM CDTSevere Thunderstorm WarningOUNPayne40 min
May 19, 7:58 PM CDTSevere Thunderstorm WarningOUNLincoln47 min
May 19, 8:01 PM CDTSevere Thunderstorm WarningOUNLogan44 min
May 19, 8:11 PM CDTSevere Thunderstorm WarningOUNCleveland, Oklahoma, Pottawatomie49 min
May 19, 8:45 PM CDTSevere Thunderstorm WarningOUNLincoln45 min
May 19, 8:58 PM CDTSevere Thunderstorm WarningOUNLogan, Oklahoma47 min
May 19, 9:22 PM CDTSevere Thunderstorm WarningOUNPottawatomie, Seminole23 min
May 19, 9:28 PM CDTSevere Thunderstorm WarningOUNCanadian32 min
May 19, 9:39 PM CDTSevere Thunderstorm WarningOUNLincoln, Pottawatomie, Seminole66 min
May 19, 9:44 PM CDTSevere Thunderstorm WarningOUNCanadian, Oklahoma46 min
May 19, 10:03 PM CDTFlash Flood WarningOUNOklahoma117 min
May 19, 10:28 PM CDTSevere Thunderstorm WarningOUNCanadian, Oklahoma62 min
May 19, 10:41 PM CDTSevere Thunderstorm WarningOUNPottawatomie49 min
May 19, 11:30 PM CDTSevere Thunderstorm WarningOUNCanadian, Oklahoma60 min
May 20, 12:44 AM CDTSevere Thunderstorm WarningOUNOklahoma61 min
May 20, 12:49 AM CDTSevere Thunderstorm WarningOUNPottawatomie56 min
May 20, 1:33 AM CDTSevere Thunderstorm WarningOUNLincoln42 min
May 20, 1:49 AM CDTSevere Thunderstorm WarningOUNHughes, Seminole56 min

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.