Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 241, NWS Norman, OK
NWS Norman, OK issued this severe thunderstorm warning at May 18, 1990, 8:35 PM CDT for Harper County, Oklahoma. It was in force for 55 min. 1 report 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
- May 18, 1990, 8:35 PM CDT (01:35 UTC)
- Expired
- May 18, 1990, 9:30 PM CDT
- In force
- 55 min
- Issued by
- NWS Norman, OK
- Area
- Whole counties
County Harper 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 |
|---|---|---|---|
| May 18, 8:42 PM CDT | Hail 1.75 | Harper, 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
Dodge City, (KDDC), launched 00:00Z, 1.6 hours before the alert went out and 111 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
- 1529 J/kg
- Mixed-layer CIN
- -73 J/kg
- Mixed-layer LCL
- 1260 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 275 m²/s²
- 0-3 km storm-relative helicity
- 444 m²/s²
- Significant tornado parameter
- 2.3
- Supercell composite
- 19.7
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 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, May 18, 7:28 PM CDT, 1 hour 7 minutes before
OKZ004-009-014-021-190200 SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OKLAHOMA CITY OK 728 PM CDT FRI MAY 18 1990 ...STRONG THUNDERSTORMS APPROACHING THE WESTERN OKLAHOMA BORDER... AT 726 PM RADAR INDICATED A SEVERE THUNDERSTORM NEAR WHEELER IN THE TEXAS PANHANDLE MOVING NORTHEAST AT 25 MPH. THIS THUNDERSTORM WILL MOVE INTO WESTERN OKLAHOMA...MOST LIKELY IN ROGER MILLS COUNTY NEAR REYDON...IN THE NEXT HOUR. HAIL...STRONG WINDS...AND TORRENTIAL RAINS ARE LIKELY WITH THIS STORM. RESIDENTS OF WESTERN OKLAHOMA SHOULD REMAIN ALERT THIS EVENING AS THUNDERSTORMS APPROACH. THE NATIONAL WEATHER SERVICE WILL CONTINUE TO MONITOR THE DEVELOPMENT OF THUNDERSTORMS AND ISSUE STATEMENTS AND WARNINGS AS NECESSARY. A TORNADO WATCH REMAINS IN EFFECT FOR PORTIONS OF WESTERN OKLAHOMA UNTIL 10 PM. UTAH AND IS FORECAST TO MOVE INTO WESTERN KANSAS EARLY TONIGHT. AS THE NORTHWARD FEED OF UNSTABLE AIR CONTINUES THIS AFTERNOON A DRY LINE WILL DEVELOP NORTH-SOUTH FROM THE TEXAS PANHANDLE INTO WESTERN KANSAS. THUNDERSTORMS ARE EXPECTED TO DEVELOP RAPIDLY LATE THIS AFTERNOON ALONG THE DRY LINE AS THE UPPER SYSTEM ARRIVES. THIS ACTIVITY IS EXPECTED TO MOVE EASTWARD ACROSS THE OKLAHOMA PANHANDLE INTO NORTHWEST OKLAHOMA THIS EVENING AND CONTINUE EASTWARD TONIGHT. THE UPPER SYSTEM MOVING INTO KANSAS TONIGHT WILL AFFECT MAINLY NORTHWESTERN OKLAHOMA THIS EVENING. FURTHER SOUTH THE EFFECTS OF THIS SYSTEM WILL NOT BE AS STRONG. HOWEVER WITH WESTERN AND CENTRAL OKLAHOMA DESTABILIZING THIS AFTERNOON... THUNDERSTORMS MAY REDEVELOP IN THESE AREAS WHERE BOUNDARIES LEFT OVER FROM THE ACTIVITY THIS MORNING PROVIDE A FOCUS. INSTABILITY AND WINDS ALOFT INDICATE THE LIKELIHOOD OF LARGE HAIL AND DAMAGING WINDS WITH SOME STORMS... AND THE POSSIBILITY OF TORNADOES ESPECIALLY IN THE MODERATE RISK AREA OF NORTHWEST OKLAHOMA. THE SEVERE WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND AS SEVERAL MORE SYSTEMS COME OUT OF THE SOUTHWEST INTO THE PLAINS. THERE IS A POSSIBLITY OF SIGNIFICANT SEVERE WEATHER... INCLUDING TORNADOES... IN THE STATE BOTH SATURDAY AND SUNDAY. RESIDENTS THROUGHOUT THE STATE ARE ADVISED TO REVIEW SEVERE WEATHER SAFETY RULES AND KEEP UP WITH THE LATEST WEATHER INFORMATION THROUGHOUT THE WEEKEND.
Special weather statement, May 18, 7:29 PM CDT, 1 hour 6 minutes before
OKZ004-009-014-021-190200 SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OKLAHOMA CITY OK 728 PM CDT FRI MAY 18 1990 ...STRONG THUNDERSTORMS APPROACHING THE WESTERN OKLAHOMA BORDER... AT 726 PM RADAR INDICATED A SEVERE THUNDERSTORM NEAR WHEELER IN THE TEXAS PANHANDLE MOVING NORTHEAST AT 25 MPH. THIS THUNDERSTORM WILL MOVE INTO WESTERN OKLAHOMA...MOST LIKELY IN ROGER MILLS COUNTY NEAR REYDON...IN THE NEXT HOUR. HAIL...STRONG WINDS...AND TORRENTIAL RAINS ARE LIKELY WITH THIS STORM. RESIDENTS OF WESTERN OKLAHOMA SHOULD REMAIN ALERT THIS EVENING AS THUNDERSTORMS APPROACH. THE NATIONAL WEATHER SERVICE WILL CONTINUE TO MONITOR THE DEVELOPMENT OF THUNDERSTORMS AND ISSUE STATEMENTS AND WARNINGS AS NECESSARY. A TORNADO WATCH REMAINS IN EFFECT FOR PORTIONS OF WESTERN OKLAHOMA UNTIL 10 PM.
The office that day
Everything else NWS Norman, OK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 18, 8:05 PM CDT | Severe Thunderstorm Warning | OUN | Roger Mills | 40 min |
| May 18, 8:44 PM CDT | Severe Thunderstorm Warning | OUN | Roger Mills | 46 min |
| May 18, 8:58 PM CDT | Tornado Warning | OUN | Harper | 32 min |
| May 19, 12:38 AM CDT | Severe Thunderstorm Warning | OUN | Pontotoc | 52 min |
| May 19, 6:25 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln | 50 min |
| May 19, 6:47 PM CDT | Severe Thunderstorm Warning | OUN | Payne | 28 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.