Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 431, NWS Norman, OK

August 18, 1997Coal County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Aug 18, 1997, 3:44 PM CDT for Coal County, Oklahoma. It was in force for 46 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
Aug 18, 1997, 3:44 PM CDT (20:44 UTC)
Expired
Aug 18, 1997, 4:30 PM CDT
In force
46 min
Issued by
NWS Norman, OK
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Coal County, OK

The radar

The Norman radar (KTLX), 122 km from the middle of the area, began a volume at 20:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 18, 4:25 PM CDTThunderstorm WindClarita, OKA three-foot diameter tree was uprooted.

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.

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 8.7 hours before the alert went out and 123 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 12:00Z on 1997-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1292 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 12:00Z on 1997-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 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
1292 J/kg
Mixed-layer CIN
-141 J/kg
Mixed-layer LCL
707 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
185 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 severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Norman, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 18, 3:30 PM CDT, 14 minutes earlier.

Area forecast discussion, Aug 18, 3:30 PM CDT, 14 minutes before
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In the hours before

Special weather statement, Aug 18, 12:27 PM CDT, 3 hours 17 minutes before
OKZ004>053-TXZ083>090-191100-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1230 PM CDT MON AUG 18 1997

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
OVERNIGHT OVER MOST OF CENTRAL AND WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS. LARGE HAIL AND VERY HEAVY RAIN ARE THE MAIN THREATS...

THE SLIGHT RISK AREA IS TO THE WEST OF A LINE FROM PONCA CITY TO
HOLDENVILLE TO DURANT.

A STATIONARY FRONT EXTENDS ACROSS SOUTHERN OKLAHOMA...WITH HOT AND HUMID
AIR TO THE SOUTH OF THIS FRONT OVER THE RED RIVER VALLEY OF OKLAHOMA AND
NORTH TEXAS. THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE FRONT AROUND
MID AFTERNOON AND LAST THROUGH SUNSET. INITIAL DEVELOPMENT WILL LIKELY
OCCUR IN THE AREA FROM VERNON TEXAS NORTHEAST TOWARD LAWTON AND ARDMORE.
THE ATMOSPHERE ACROSS THE RED RIVER VALLEY AREA IS EXPECTED TO BECOME
VERY UNSTABLE...AND ANY STORMS THAT DEVELOP MAY PRODUCE LARGE HAIL. THE
POTENTIAL ALSO EXISTS FOR ISOLATED FLASH FLOODING AS THE STORMS MOVE
VERY SLOWLY AND PERSIST OVER AREAS THAT SAW HEAVY RAIN LAST NIGHT.

A STORM SYSTEM IN THE UPPER LAYERS OF THE ATMOSPHERE IS MOVING ACROSS
THE SOUTHERN ROCKIES AND IS APPROACHING THE PANHANDLE REGION.
THUNDERSTORM DEVELOPMENT WILL ALSO OCCUR OVER WESTERN OKLAHOMA THIS
AFTERNOON AS THIS STORM APPROACHES. ALTHOUGH A FEW OF THE STORMS MAY
PRODUCE LARGE HAIL...THE MAIN THREAT WILL BE FOR FLASH FLOODING...
ESPECIALLY OVER NORTHWEST AND NORTH-CENTRAL OKLAHOMA OVERXNIGHT.

EMERGENCY MANAGEMENT OFFICIALS AND SPOTTER GROUPS IN THE SLIGHT RISK
AREA SHOULD MONITOR THE LATEST FORECASTS AND BE READY FOR ACTIVATION
THIS AFTERNOON THROUGH TONIGHT.
Special weather statement, Aug 18, 12:30 PM CDT, 3 hours 14 minutes before
OKZ004>053-TXZ083>090-191100-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1230 PM CDT MON AUG 18 1997

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
OVERNIGHT OVER MOST OF CENTRAL AND WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS. LARGE HAIL AND VERY HEAVY RAIN ARE THE MAIN THREATS...

THE SLIGHT RISK AREA IS TO THE WEST OF A LINE FROM PONCA CITY TO
HOLDENVILLE TO DURANT.

A STATIONARY FRONT EXTENDS ACROSS SOUTHERN OKLAHOMA...WITH HOT AND HUMID
AIR TO THE SOUTH OF THIS FRONT OVER THE RED RIVER VALLEY OF OKLAHOMA AND
NORTH TEXAS. THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE FRONT AROUND
MID AFTERNOON AND LAST THROUGH SUNSET. INITIAL DEVELOPMENT WILL LIKELY
OCCUR IN THE AREA FROM VERNON TEXAS NORTHEAST TOWARD LAWTON AND ARDMORE.
THE ATMOSPHERE ACROSS THE RED RIVER VALLEY AREA IS EXPECTED TO BECOME
VERY UNSTABLE...AND ANY STORMS THAT DEVELOP MAY PRODUCE LARGE HAIL. THE
POTENTIAL ALSO EXISTS FOR ISOLATED FLASH FLOODING AS THE STORMS MOVE
VERY SLOWLY AND PERSIST OVER AREAS THAT SAW HEAVY RAIN LAST NIGHT.

A STORM SYSTEM IN THE UPPER LAYERS OF THE ATMOSPHERE IS MOVING ACROSS
THE SOUTHERN ROCKIES AND IS APPROACHING THE PANHANDLE REGION.
THUNDERSTORM DEVELOPMENT WILL ALSO OCCUR OVER WESTERN OKLAHOMA THIS
AFTERNOON AS THIS STORM APPROACHES. ALTHOUGH A FEW OF THE STORMS MAY
PRODUCE LARGE HAIL...THE MAIN THREAT WILL BE FOR FLASH FLOODING...
ESPECIALLY OVER NORTHWEST AND NORTH-CENTRAL OKLAHOMA OVERNIGHT.

EMERGENCY MANAGEMENT OFFICIALS AND SPOTTER GROUPS IN THE SLIGHT RISK
AREA SHOULD MONITOR THE LATEST FORECASTS AND BE READY FOR ACTIVATION
THIS AFTERNOON THROUGH TONIGHT.
Local storm report, Aug 18, 3:10 PM CDT, 34 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OKLAHOMA
0310 PM CDT MON AUG 18 1997

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0220 PM    SULPHUR                    OK   .75 INCH HAIL AT CHICKASAW
08/18/97   MURRAY                          NATIONAL RECREATION AREA.

0300 PM    SULPHUR                    OK   FLASH FLOODING
08/18/97   MURRAY                          POLICE DEPT. REPORTED CITY
                                           PARK IN SULPHUR CLOSED DUE
                                           HIGH WATER.

0240 PM   MILL CREEK                  OK   WIND DAMAGE.
08/18/97  JOHNSTON                         E.O.C. REPORTED SIDING BLOWN
.                                          OFF HOUSE IN MILL CREEK.

0320 PM   7 S FITTSTOWN               OK   .75 INCH HAIL.
08/18/97  PONTOTOC

J
Local storm report, Aug 18, 3:42 PM CDT, 2 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OKLAHOMA
0310 PM CDT MON AUG 18 1997

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0220 PM    SULPHUR                    OK   .75 INCH HAIL AT CHICKASAW
08/18/97   MURRAY                          NATIONAL RECREATION AREA.

0300 PM    SULPHUR                    OK   FLASH FLOODING
08/18/97   MURRAY                          POLICE DEPT. REPORTED CITY
                                           PARK IN SULPHUR CLOSED DUE
                                           HIGH WATER.

0240 PM   MILL CREEK                  OK   WIND DAMAGE.
08/18/97  JOHNSTON                         E.O.C. REPORTE:D SIDING BLOWN
.                                          OFF HOUSE IN MILL CREEK.

0320 PM   7 S FITTSTOWN               OK   .75 INCH HAIL.
08/18/97  PONTOTOC

J

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 11:26 PM CDTSevere Thunderstorm WarningOUNSeminole64 min
Aug 18, 9:00 AM CDTFlash Flood WarningOUNKay3 hr
Aug 18, 2:03 PM CDTSevere Thunderstorm WarningOUNMurray, Pontotoc42 min
Aug 18, 2:25 PM CDTFlash Flood WarningOUNMurray3 hr
Aug 18, 2:43 PM CDTSevere Thunderstorm WarningOUNJohnston, Pontotoc47 min
Aug 18, 4:55 PM CDTSevere Thunderstorm WarningOUNJefferson, Stephens50 min
Aug 18, 5:33 PM CDTSevere Thunderstorm WarningOUNCanadian, Kingfisher42 min
Aug 18, 5:57 PM CDTSevere Thunderstorm WarningOUNGreer, Harmon48 min
Aug 18, 6:30 PM CDTSevere Thunderstorm WarningOUNGrady30 min
Aug 17, 7:00 PM CDTSevere Thunderstorm WarningOUNArcher, Wichita30 min
Aug 17, 7:27 PM CDTSevere Thunderstorm WarningOUNArcher48 min
Aug 17, 7:37 PM CDTSevere Thunderstorm WarningOUNFoard, Wilbarger53 min
Aug 17, 7:43 PM CDTTornado WarningOUNArcher32 min
Aug 17, 7:57 PM CDTSevere Thunderstorm WarningOUNKnox48 min
Aug 17, 8:14 PM CDTSevere Thunderstorm WarningOUNArcher46 min
Aug 17, 8:41 PM CDTSevere Thunderstorm WarningOUNKnox49 min
Aug 17, 9:30 PM CDTSevere Thunderstorm WarningOUNBaylor, Knox60 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 1997Every severe thunderstorm warning in 1997

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; radar from the NEXRAD Level II archive.