Alert archive / Oklahoma / Flash Flood Warnings in 1990
Flash Flood Warning 11, NWS Norman, OK
NWS Norman, OK issued this flash flood warning at Apr 21, 1990, 5:42 PM CDT for Carter County, Johnston County, Murray County, Oklahoma. It was in force for 2 hr.
The area
The counties it named.
The facts
- Issued
- Apr 21, 1990, 5:42 PM CDT (22:42 UTC)
- Expired
- Apr 21, 1990, 7:45 PM CDT
- In force
- 2 hr
- Issued by
- NWS Norman, OK
- Area
- Whole counties
Counties Carter County, OK, Johnston County, OK, Murray 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 12:00Z, 10.7 hours before the alert went out and 103 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.
- Mixed-layer CAPE
- 369 J/kg
- Mixed-layer CIN
- -102 J/kg
- Mixed-layer LCL
- 789 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 86 m²/s²
- 0-3 km storm-relative helicity
- 85 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KOKC 212243 RRA FFWOKC OKC019-069-099-220045- BULLETIN - EBS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE OKLAHOMA CITY OK 542 PM CDT SAT APR 21 1990 THE NATIONAL WEATHER SERVICE IN OKLAHOMA CITY HAS ISSUED A FLASH FLOOD WARNING EFFECTIVE UNTIL 745 PM CDT FOR THE FOLLOWING OKLAHOMA LOCATIONS... IN SOUTHEAST OKLAHOMA ...EASTERN CARTER COUNTY...JOHNSTON COUNTY...SOUTHERN MURRAY COUNTY AT 542 PM RADAR INDICATED STRONG THUNDERSTORMS PRODUCING TORRENTIAL RAINFALL FROM GENE AUTRY...TO JUST SOUTH OF SULPHUR...TO NEAR TISHOMINGO. THE STORMS WERE DRIFTING VERY SLOWLY SOUTHWARD PRODUCING LOCALLY VERY HEAVY RAINFALL AMOUNTS. WATER 2 FEET DEEP HAS BEEN REPORTED IN TISHOMINGO FROM THESE STORMS. A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS IMMINENT. MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS THE ROADWAY. NEVER TRY TO CROSS A F(LOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.
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, Apr 21, 12:53 PM CDT, 4 hours 49 minutes before
OKZALL-221200- OKLAHOMA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE OKLAHOMA CITY OK 100 PM CDT SAT APR 21 1990 NO SEVERE THUNDERSTORMS ARE FORECAST IN OKLAHOMA THIS AFTERNOON OR TONIGHT. WIDELY SCATTERED THUNDERSTORMS MAY DEVELOP THIS AFTER NOON DUE TO HEATING AND AN ABUNDANCE OF LOW LEVEL MOISTURE...BUT THEY ARE NOT EXPECTED TO BECOME SEVERE. LOW CLOUDS AND FOG WHICH BLANKETED MUCH OF THE STATE EARLY THIS MORNING WERE BURNING OFF BY MIDDAY. HOWEVER DEWPOINTS REMAIN FAIRLY HIGH AND IF AFTERNOON TEMPERATURES RISE INTO THE LOW AND MID 80S WIDELY SCATTETED THUNDERSTORMS MAY DEVELOP IN MOST ANY SECTION OF THE STATE. THE WIND PATTERNS IN THE MID LEVELS OF THE ATMOSPHERE ARE RATHER WEAK AND UNFAVORABLE FOR THE OCCURENCE OF ORGANIZED SEVERE THUNDERSTORMS...HOWEVER ANY THUNDERSTORMS THAT FORM THIS AFTERNOON COULD PRODUCE BRIEF GUSTY WIND.
Special weather statement, Apr 21, 5:35 PM CDT, 7 minutes before
TXZ020-212330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WICHITA FALLS TX 535 PM CDT SAT APR 21 1990 ...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR JACK AND MONTAGUE COUNTIES UNTIL 9 PM CDT... AT 530 PM CDT THE WICHITA FALLS RADAR SHOWED VERY STRONG THUNDERSTORMS OVER SOUTHWEST MONTAGUE AND EXTREME NORTHEAST JACK COUNTIES. THESE STORMS AND PRODUCING VERY HEAVY RAINS AND COULD ALSO PRODUCE STRONG WINDS AND SMALL HAIL. THESE STORMS ARE MOVING ACROSS AREAS THAT HAVE RECEIVED VERY HEAVY RAINS DURING THE AFTERNOON. SOME MINOR FLOODING OF LOW-LYING FLOOD PRONE AREAS MAY BE EXPERIENCED. MOVEMENT WAS SLOWLY TO THE EAST AT LESS THAN 10 MPH.
The office that day
Everything else NWS Norman, OK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 1:58 PM CDT | Severe Thunderstorm Warning | OUN | Coal | 32 min |
| Apr 21, 2:28 PM CDT | Severe Thunderstorm Warning | OUN | Coal | 47 min |
| Apr 21, 2:33 PM CDT | Flash Flood Warning | OUN | Coal | 117 min |
| Apr 21, 3:18 PM CDT | Severe Thunderstorm Warning | OUN | Johnston | 42 min |
| Apr 21, 3:48 PM CDT | Flash Flood Warning | OUN | Johnston | 117 min |
| Apr 21, 4:48 PM CDT | Severe Thunderstorm Warning | OUN | Carter, Johnston, Marshall | 57 min |
| Apr 21, 5:56 PM CDT | Severe Thunderstorm Warning | OUN | Bryan, Johnston | 49 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.