Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 151, NWS Norman, OK
NWS Norman, OK issued this severe thunderstorm warning at Apr 21, 1990, 4:48 PM CDT for Carter County, Johnston County, Marshall County, Oklahoma. It was in force for 57 min. 2 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Apr 21, 1990, 4:48 PM CDT (21:48 UTC)
- Expired
- Apr 21, 1990, 5:45 PM CDT
- In force
- 57 min
- Issued by
- NWS Norman, OK
- Area
- Whole counties
Counties Carter County, OK, Johnston County, OK, Marshall County, OK
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Apr 21, 5:10 PM CDT | Hail 0.75 | Johnston, OK | |
| Apr 21, 5:50 PM CDT | Hail 1.75 | Johnston, OK |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Norman, OK (KOUN), launched 12:00Z, 9.8 hours before the alert went out and 122 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 212151 SVROKC OKC019-069-095-212245- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE OKLAHOMA CITY OK 448 PM CDT SAT APR 21 1990 THE NATIONAL WEATHER SERVICE IN OKLAHOMA CITY HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 545 PM CDT FOR THE FOLLOWING OKLAHOMA LOCATIONS... IN SOUTHEAST OKLAHOMA ...EASTERN CARTER COUNTY...SOUTHERN JOHNSTON COUNTY ...NORTHERN MARSHALL COUNTY AT 448 PM RADAR INDICATED SEVERE THUNDERSTORMS 3 MILES NORTHEAST OF GENE AUTRY AND NEAR TISHIMINGO. THE STORMS WERE MOVING SOUTH AT 10 MPH. LARGE HAIL...DAMAGING WINDS AND TORRENTIAL RAINFALL IS POSSIBLE WITH THESE STORMS. WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A STRONG BUILDING. DO NOT STAND BY WINDOWS. DON'T USE TELEPHONES OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM HAS PASSED. MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.
What forecasters said that day
The local office's own words before this severe thunderstorm 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, 3 hours 55 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.
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, 5:42 PM CDT | Flash Flood Warning | OUN | Carter, Johnston, Murray | 2 hr |
| Apr 21, 5:56 PM CDT | Severe Thunderstorm Warning | OUN | Bryan, Johnston | 49 min |
Nearby
Severe Thunderstorm Warnings in Oklahoma, 1990Every severe thunderstorm 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.