Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 287, NWS Tulsa, OK

July 20, 1997Osage County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Jul 20, 1997, 6:32 PM CDT for Osage County, Oklahoma. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 20, 1997, 6:32 PM CDT (23:32 UTC)
Expired
Jul 20, 1997, 7:15 PM CDT
In force
43 min
Issued by
NWS Tulsa, OK
Area
Whole counties

County Osage County, OK

The radar

The Tulsa radar (KINX), 90 km from the middle of the area, began a volume at 23:34 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, 11.5 hours before the alert went out and 181 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 1997-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1861 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 1997-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 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
1861 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
1021 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
23 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 KTUL 202331 RRA
SVRTUL
OKC113-210015-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
632 PM CDT SUN JUL 20 1997
 
THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  715 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTHEAST OKLAHOMA
 
   ...SOUTHEASTERN OSAGE COUNTY
 
AT 630 PM...RADAR INDICATED A SEVERE THUNDERSTORM CENTERED NEAR DOWNTOWN
TULSA MOVING NORTHWEST AT AROUND 10 MPH. PARTS OF THE TULSA METROPOLITAN
AREA IN EXTREME SOUTHEAST OSAGE COUNTY INCLUDING AREAS NORTHEAST OF
SAND SPRINGS WILL BE AFFECTED BY THIS STORM.
 
HAIL TO THE SIZE OF QUARTERS AND WIND GUSTS TO 70 MPH CAN BE EXPECTED
IN THE WARNED AREA.
 
KEEP TUNED TO THIS STATION FOR THE LATEST WEATHER BULLETINS.

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 Tulsa, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 20, 5:40 PM CDT, 52 minutes earlier.

Area forecast discussion, Jul 20, 5:40 PM CDT, 52 minutes before
FPUS3 KTUL 202240
AFDTUL

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
540 PM CDT SUN JUL 20 1997

UPDATED ZNS TO ADD MENTION OF SCT TSRA...MAINLY ALONG WK SFC
CONVERGENCE AREA IN TULSA AREA. /13
.TUL...
OK...NONE.
AR...NONE.

In the hours before

Special weather statement, Jul 20, 1:00 PM CDT, 5 hours 32 minutes before
ARZ001-002-010-011-019-029-OKZ054>076-211200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
100 PM CDT SUN JUL 20 1997

NO SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON OR TONIGHT.

SATELLITE OBSERVATIONS AND THE MORNING WEATHER BALLOON DATA
CONTINUE TO INDICATE A MINIMAL THREAT FOR SEVERE THUNDERSTORMS
ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.  MOST OF ANY
SIGNIFICANT UPPER LEVEL SUPPORT WAS IN THE FORM OF A WEAK
DISTURBANCE ACROSS CENTRAL KANSAS.  AT THE SURFACE...OUTFLOW
BOUNDARIES FROM MORNING THUNDERSTORMS OVER SOUTHERN KANSAS HAVE
MOVED SOUTHEASTWARD INTO EASTERN OKLAHOMA.

AS AFTERNOON TEMPERATURES RISE INTO THE LOWER 90S...WIDELY
SCATTERED THUNDERSTORMS WILL FORM ACROSS THE REGION.  ALTHOUGH THE
THUNDERSTORMS ARE EXPECTED TO REMAIN BELOW SEVERE LIMITS...THE
LINGERING OUTFLOW BOUNDARIES COULD FOCUS A FEW ISOLATED STRONG
THUNDERSTORMS WHICH MAY BRIEFLY PRODUCE SMALL HAIL...VERY HEAVY
RAINS...AND GUSTY DOWNBURST WINDS.  THE THUNDERSTORMS SHOULD
DIMINISH WITH THE LOSS OF DAYTIME HEATING AROUND SUNSET.

WITH THE LACK OF SIGNIFICANT UPPER LEVEL SUPPORT AND LITTLE FOCUS
EXPECTED AT THE SURFACE...MOST OF ANY THUNDERSTORMS LATE TONIGHT
AND INTO EARLY MONDAY SHOULD REMAIN NORTH OF EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 5:50 PM CDTSevere Thunderstorm WarningTSATulsa25 min
Jul 20, 6:08 PM CDTFlash Flood WarningTSATulsa2 hr
Jul 20, 6:14 PM CDTSevere Thunderstorm WarningTSATulsa31 min
Jul 20, 6:39 PM CDTSevere Thunderstorm WarningTSATulsa51 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.