Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 288, NWS Tulsa, OK

July 20, 1997Tulsa County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Jul 20, 1997, 6:39 PM CDT for Tulsa County, Oklahoma. It was in force for 51 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
Jul 20, 1997, 6:39 PM CDT (23:39 UTC)
Expired
Jul 20, 1997, 7:30 PM CDT
In force
51 min
Issued by
NWS Tulsa, OK
Area
Whole counties

County Tulsa County, OK

The radar

The Tulsa radar (KINX), 34 km from the middle of the area, began a volume at 23:39 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
Jul 20, 7:05 PM CDTThunderstorm Wind 52Owasso, OKA severe thunderstorm moved slowly north northwest through Tulsa County and produced large hail and damaging winds. Thunderstorm winds up to 70 miles an hour downed trees, power lines, and fences in Broken Arrow, mainly between 71st and 101st Streets South and

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, 11.7 hours before the alert went out and 166 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 202339 RRA
SVRTUL
OKC143-210030-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
639 PM CDT SUN JUL 20 1997
 
THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  730 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTHEAST OKLAHOMA
 
   ...CENTRAL AND NORTHERN TULSA COUNTY
 
AT 637PM...RADAR CONTINUED TO SHOW A SEVERE THUNDERSTORM DRIFTING
NORTHWARD INTO CENTRAL AND NORTHERN TULSA COUTNY AND EXTENDING JUST INTO
THE SOUTHEAST CORNER OF OSAGE COUNTY. THE STRONGEST PART OF THE STORM
WAS LOCATED NORTH OF 11TH STREET SOUTH NEAR LEWIS AVENUE. THE STORM WILL
DRIFT INTO THE OWASSO AND POSSIBLY THE SPEERY AREAS BY 7PM.
 
WINDS AS HIGH AS 70 MPH AND HAIL AS LARGE AS QUARTERS HAS BEEN REPORTED
WITH THIS STORM.
 
DURING THE STORM MOVE INDOORS AND STAY AWAY FROM WINDOWS.
TO PROTECT YOURSELF FROM LIGHTNING DO NOT USE THE TELEPHONE
OR HAND HELD ELECTRICAL APPLIANCES...UNLESS IN AN EMERGENCY.
MOTORISTS SHOULD BE ALERT FOR WATER ON ROADWAYS AND NEVER
DRIVE ONTO A FLOODED ROAD.
 
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, 59 minutes earlier.

Area forecast discussion, Jul 20, 5:40 PM CDT, 59 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 39 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, 6:32 PM CDTSevere Thunderstorm WarningTSAOsage43 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.