Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 78, NWS Tulsa, OK

April 11, 1997McIntosh County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Apr 11, 1997, 5:22 AM CDT for McIntosh County, Oklahoma. It was in force for 53 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: Apr 11, 1997, 5:22 AM CDT (10:22 UTC)
Expired: Apr 11, 1997, 6:15 AM CDT
In force: 53 min
Issued by: NWS Tulsa, OK
Area: Whole counties

County McIntosh County, OK

The radar

The Tulsa radar (KINX), 90 km from the middle of the area, began a volume at 10:24 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

Time	Report	Where	Remark
Apr 11, 5:43 AM CDT	Thunderstorm Wind 52	Eufaula, OK	A severe thunderstorm produced 60 mile an hour winds in Eufaula.

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 00:00Z, 10.4 hours before the alert went out and 158 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1196 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 191 m²/s²
0-3 km storm-relative helicity: 287 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KTUL 111023 RRA
SVRTUL
OKC091-111115-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
522 AM CDT FRI APR 11 1997
 
THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  615 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN EAST CENTRAL OKLAHOMA
 
   ...MCINTOSH COUNTY
 
AT 520 AM RADAR SHOWED A LINE OF SEVERE THUNDERSTORMS FROM HITCHITA TO
RAIFORD. THESE STORMS WERE MOVING EAST AT 40 MPH AND WILL MOVE THROUGH
THE CHECOTAH AND EUFAULA AREAS BY 6AM.
 
HAIL TO THE SIZE OF DIMES AND WIND GUSTS TO 60 MPH CAN BE EXPECTED
IN THE WARNED AREA.
 
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 Apr 11, 4:13 AM CDT, 1 hour 9 minutes earlier.

Area forecast discussion, Apr 11, 4:13 AM CDT, 1 hour 9 minutes before

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
410 AM CDT FRI APR 11 1997

SEVERAL PROBLEMS TO CONTEND WITH THIS MORNING. THREAT OF SVR SHOULD
BE CONFINED TO SE OK TODAY BEFORE FRONTAL/OUTFLOW BOUNDARY PASSAGE.
WEAK INSTABILITY WILL BE A LIMITING FACTOR. ANOTHER REAL PROBLEM IS
THREAT OF HEAVY RAINFALL. 00Z RAOBS SHOWED PLENTY OF H8 MOISTURE
LIFTING OVER FRONTAL ZONE. TSRA HAS BEEN NOTED AS FAR NORTH AS ICT
WHERE SFC TEMPS ARE IN THE MID 30S. WITH ELEVATED INSTABILITY AND
H5 S/W NOT PROGGED TO MOVE THROUGH UNTIL AFTER 00Z...SLOW MOVEMENT
OF FRONT WILL RESULT. MODEL QPF MAY BE TOO LOW WITH THIS SCENARIO.
88D RAINFALL ESTIMATES BECOME QUESTIONABLE BEHIND FRONT WHERE
TOTALS ARE GOING OVER 3 INCHES. BELIEVE MELTING SNOW AT 5-10 KFT IS
CAUSING SOME BRIGHT-BANDING SIMILAR TO A COUPLE DAYS AGO. MESONETS
STILL SHOWS HEFTY ACCUMULATIONS BEHIND FRONT THOUGH WITH ALMOST AN
INCH IN 3 HOURS. SATELLITE IMAGES COMING IN AFTER ECLIPSE SHOWS
WARMING TOPS WITH ACTIVITY PUSHING INTO THE COLD AIR IN SE KS BUT
MORE ACTIVITY SEEN ON 88D AND IR PIX TO THE WEST. WILL GO WITH FFA
FOR ABOUT NRN 1/2. MODELS AGREE THAT BEST VERTICAL MOTION DUE TO
ISENTROPIC LIFT AND UPPER DIVERGENCE WILL TRACK OVER NRN ZONES AND
NOT AFFECT SE OK AND WC AR QUITE AS MUCH.

ANOTHER PROBLEM IS TEMPERATURES. BELIEVE THAT SWITCH TO NLY WINDS
TODAY WILL BE SOONER THAN MODELS ARE FCSTG AS DIABATIC EFFECT OF
TSRA WILL ENHANCE BUILDING PRESSURES AND COOLER TEMPERATURES AT THE
SFC. SFC DPS ARE FAIRLY LOW STILL AND WET BULB TEMPS AHEAD OF THE
FRONT ARE ONLY IN THE 50S. WILL TRY TO NOT GET TOO FANCY WITH
TIMING OF WIND SHIFT AND DROP IN TEMPS TODAY. TEMPS TONIGHT LOOK
TOO COLD ON THE AVN GUIDANCE WITH LOW CLOUDS AND STRONG NW WINDS
HELPING MECHANICAL MIXING OF BL. H8 TEMPS ARE VERY COLD FOR THIS
TIME OF YEAR...BUT HAVE DECIDED TO STICK WITH COMPROMISE FAN/FWC
MINS. WILL PROB HAVE TO GO WITH FREEZE WARNING FOR FAR NW ZONES FOR
TONIGHT. VERY UNPLEASANT SAT IN STORE FOR NW AR AND NE OK WITH
CLOUDS AND COLD NW WINDS. H8 TEMP TROUGH RIGHT OVER US AND AVN/ETA
KEEP US IN THE COOLER! ETA 2M TEMPS IN THE LOW 40S WHILE FAN MAX AT
TUL/SGF IS 38/35! WITH SOME HOPE FOR SOME SUNSHINE LATE IN THE
DAY... HAVE GONE ABOVE THE FAN FOR MAX TEMPS SAT...BUT MOST OF THE
DAY WILL BE A COOL ONE. THE COLDEST NIGHT COULD BE SAT NIGHT/SUN
MORNING WITH CLEAR SKIES AND WEAKENING WINDS.

FINAL PROBLEM WOULD BE ANY CHC OF MIXED PHASE PRECIPITATION LATE
TODAY AND EARLY TONIGHT.  ONLY REAL CHC OF THIS SHOULD BE OVER FAR
NW ZONES LATE TODAY. ETA MODEL IS THE MOST AGGRESSIVE WITH THE COLD
AIR TODAY AND SHOWS CRITICAL 1000-850 THICKNESSES DIVING INTO THE
NRN TX LATE TODAY BUT HOLDING JUST TO OUR WEST. BY THE TIME THE
SNOW/SLEET THRESHOLDS ARE MET HERE...MOST OF THE LIFT WILL BE WELL
OFF TO OUR NE WITH STG NWLY SFC WINDS IN PLACE. WILL MENTION
POSSIBILITY OF MIXED PRECIP IN FAR NW ZONES LATE TODAY.

NEW MRF IS NOT IN YET...BUT 10/12Z ECMWF RUN SUPPORTS THE HOPE OF
WARMING TEMPERATURES OFFERED BY THE OLD MRF RUN. WILL TRY TO LOOK
AT NEW RUN BEFORE SENDING OUT AFP. /26

1ST PD TEMPS SUBJECT TO CHANGE...
TUL 050/031 044/028 050 +200
FSM 058/038 050/030 055 +300
MLC 065/034 050/029 052 +200
BVO 043/026 043/025 049 +200
FYV 062/033 042/026 047 +400
IDB 069/042 055/032 057 8300
BYV 062/033 041/025 046 +400

.OK...FLASH FLOOD WATCH TODAY ZONES 54>71.
.AR...FLASH FLOOD WATCH TODAY ZONES 1/2/10/11.

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 11, 1:58 AM CDT	Flash Flood Warning	TSA	Osage	3 hr
Apr 11, 4:48 AM CDT	Flash Flood Warning	TSA	Osage	4 hr

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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.