Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 430, NWS Norman, OK

August 18, 1997Johnston County, Pontotoc County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Aug 18, 1997, 2:43 PM CDT for Johnston County, Pontotoc County, Oklahoma. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Aug 18, 1997, 2:43 PM CDT (19:43 UTC)
Expired: Aug 18, 1997, 3:30 PM CDT
In force: 47 min
Issued by: NWS Norman, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Johnston County, OK, Pontotoc County, OK

The radar

The Norman radar (KTLX), 108 km from the middle of the area, began a volume at 19:45 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.

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 7.7 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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

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

000 
TTAA00 KOKC 181942 RRA
SVROKC
OKC069-123-182030-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORMAN OK
243 PM CDT MON AUG 18 1997

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 330 PM CDT FOR PEOPLE IN
THE FOLLOWING COUNTIES

IN SOUTHEASTERN OKLAHOMA
     NORTHERN JOHNSTON AND SOUTHERN PONTOTOC

INCLUDING THE FOLLOWING LOCATIONS
     MILL CREEK...ROFF AND STONEWALL

AT 243 PM CDT DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 8
MILES NORTHEAST OF MILL CREEK ALONG THE JOHNSTON/PONTOTOC COUNTY LINE.
HAIL TO NICKEL SIZE AND TORRENTIAL RAIN IS LIKELY.

MOVEMENT IS SLOWLY EAST AT 5 TO 10 MPH.

MOVE TO AN INTERIOR ROOM AfWAY FROM WINDOWS AND ELECTRICAL
APPLIANCES.  HEAVY RAINS MAY QUICKLY FLOOD ROADWAYS -- DO NOT
DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

CHURCHILL

LAT...LON 3443  9651 3438  9685 3451  9681 3467  9687
          3466  9650

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 11:26 PM CDT	Severe Thunderstorm Warning	OUN	Seminole	64 min
Aug 18, 9:00 AM CDT	Flash Flood Warning	OUN	Kay	3 hr
Aug 18, 2:03 PM CDT	Severe Thunderstorm Warning	OUN	Murray, Pontotoc	42 min
Aug 18, 2:25 PM CDT	Flash Flood Warning	OUN	Murray	3 hr
Aug 18, 3:44 PM CDT	Severe Thunderstorm Warning	OUN	Coal	46 min
Aug 18, 4:55 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson, Stephens	50 min
Aug 18, 5:33 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Kingfisher	42 min
Aug 18, 5:57 PM CDT	Severe Thunderstorm Warning	OUN	Greer, Harmon	48 min
Aug 18, 6:30 PM CDT	Severe Thunderstorm Warning	OUN	Grady	30 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 1997 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.