Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 89, NWS Tulsa, OK
NWS Tulsa, OK issued this severe thunderstorm warning at Apr 20, 1997, 8:00 PM CDT for McIntosh County, Oklahoma. It was in force for 30 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 20, 1997, 8:00 PM CDT (01:00 UTC)
- Expired
- Apr 20, 1997, 8:30 PM CDT
- In force
- 30 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 01:04 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 20, 8:05 PM CDT | Hail 1 | Checotah, OK |
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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 20, 3:45 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Norman, OK (KOUN), launched 00:00Z, 1.0 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.
- Mixed-layer CAPE
- 490 J/kg
- Mixed-layer CIN
- -106 J/kg
- Mixed-layer LCL
- 2384 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- 14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KTUL 210101 RRA SVRTUL OKC091-210130- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE TULSA OK 800 PM CDT SUN APR 20 1997 THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 830 PM CDT FOR PEOPLE IN THE FOLLOWING LOCATION... IN EAST CENTRAL OKLAHOMA ...EASTERN MCINTOSH COUNTY AT 8 PM...RADAR SHOWED A SEVERE THUNDERSTORM JUST SOUTH OF CHECOTAH. THE STORM WAS MOVING EAST AT 30 MPH. HAIL TO THE SIZE OF DIMES AND WIND GUSTS TO 60 MPH CAN BE EXPECTED IN THE WARNED AREA. A TORNADO WATCH IS ALSO IN EFFECT FOR THE WARNED AREA. REMEMBER... SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING. REMAIN CALM BUT BE ALERT TO RAPIDLY CHANGING WEATHER CONDITIONS. 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 20, 3:36 PM CDT, 4 hours 24 minutes earlier.
Area forecast discussion, Apr 20, 3:36 PM CDT, 4 hours 24 minutes before
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
335 PM CDT SUN APR 20 1997
SFC LO CONTG TO DEEPEN THRU THE AFTN AND LTCD JUST NW EMP KS AT 20Z.
SFC FNT/TROF EXTNDG FRM LO DOWN TO OSAGE/PAWNEE CONTIES IN NWRN PART
OF FA...THEN ON TWRD S-CNTL OK. GUSTY SWLY SFC WNDS CONTG OUT AHD
OF BNDRY WITH DEWPTS IN THE 50S. AMS HAS CONTD TO BCM INCRSLY
UNSTBL..BUT MOISTR RMNS SHALLOW. MAIN THREAT OF BIG STMS THIS EVNG
STILL APPEARS TO BE SE KS/SW MO CLOSER TO SFC LO WHICH COULD THEN
AFFECT FAR NE OK AND NW AR. WL CARRY HIGHEST POPS THOSE LCTNS...BUT
WL CONT TO MAINTAIN AT LEAST LO POPS ACRS REMAINDER OF FA AHD OF
ADVANCING FNT/TROF. SFC LO WL CONT TO TRACK TO THE ESE OR SE ENDING
THREAT OF PRECIP MOST AREAS BY LATE EVNG. HWVR SRN PORTION OF FNT
COULD HANG UP OVR SRN ZNS.
THRU REMAINING PDS UNSETTLED WX WL CONT THRU MUCH OF THE WEEK
AS WL RMN BASICALLY IN A RATHER QUICK MOVG NWLY FLOW PTRN. PTRN
WL BE A LTL LESS AMPLIFIED ACRS THE COUNTRY...BUT WL STILL CONT TO
SEE SERIES OF S/WVS MOVG THRU THE PLNS WITH TIMING PBLMS BTWN
VARIOUS MDLS. FOR NOW WL TEND TO BROADBRUSH SLGT CHC/CHC POPS
THRU LATER PDS.
PRELIM NUMBERS: TUL 53/73/51/70 2233 BVO 49/73/48/70 1233
FSM 54/75/50/71 4233 FYV 49/68/47/68 5233
...04... MLC 54/77/51/71 3233 IDB 57/76/50/72 4233
BYV 47/68/45/68 5233
.TUL...
OK...NONE.
AR...NONE.In the hours before
Local storm report, Apr 20, 6:01 PM CDT, 1 hour 59 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
601 PM CDT SUN APR 20 1997
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0538 PM 2 SW WELCH OK .88 INCH HAIL
04/20/97 CRAIG
0550 PM NARCISSA OK .88 INCH HAIL
04/20/97 OTTAWA
0554 PM 3 S MIAMI OK 1 INCH HAIL
04/20/97 OTTAWALocal storm report, Apr 20, 7:06 PM CDT, 54 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
706 PM CDT SUN APR 20 1997
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0705 PM 2 E TULLAHASSEE OK 1 INCH HAIL
04/20/97 WAGONERSpecial weather statement, Apr 20, 7:28 PM CDT, 32 minutes before
OKZ054>076-ARZ001-002-010-011-019-029-211200- EASTERN OKLAHOMA/NORTHWEST ARKANSAS THUNDERSTORM OUTLOOK...UPDATED NATIONAL WEATHER SERVICE TULSA OK 730 PM CDT SUN APR 20 1997 NUMEROUS SEVERE THUNDERSTORMS ARE EXPECTED THIS EVENING IN SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. THE RISK OF SEVERE STORMS IS SOUTHEAST OF A LINE FROM JAY TO OKEMAH. SEVERE WEATHER WATCHES ARE IN EFFECT FOR THIS AREA UNTIL LATE EVENING. A LINE OF STRONG TO SEVERE THUNDERSTORMS HAS ALREADY DEVELOPED ACROSS EASTERN OKLAHOMA EARLY THIS EVENING. NUMEROUS SEVERE THUNDERSTORM WARNINGS WERE IN EFFECT AS OF 730 PM ALONG THIS LINE. THE STORMS HAVE DEVELOPED JUST AHEAD OF A COLD FRONT WHICH WAS MOVING INTO THE AREA. THE STORMS ARE EXPECTED TO REMAIN SEVERE THIS EVENING AS THEY MOVE ACROSS SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. THE GREATEST SEVERE WEATHER THREAT FROM THESE STORMS WILL BE LARGE HAIL AND DAMAGING WINDS. WIND PROFILES ARE A BIT MORE FAVORABLE FOR TORNADIC STORMS IN CARROLL AND MADISON COUNTIES OF NORTHWEST ARKANSAS. CURRENT RADAR INDICATIONS SUGGEST A WEAKNESS IN THE THUNDERSTORM LINE THAT IS APPROACHING EXTREME NORTHWEST ARKANSAS BUT SHOULD THE STORMS IN THIS PORTION OF THE LINE INTENSIFY...THE POTENTIAL WOULD EXIST FOR AN ISOLATED TORNADO IN CARROLL OR MADISON COUNTIES THIS EVENING. THE STORMS SHOULD BE EAST OF THE AREA BY MIDNIGHT AND THE SEVERE WEATHER THREAT WILL END BY THAT TIME. EMERGENCY MANAGEMENT AGENCIES AND SKYWARN G@ROUPS IN THE RISK AREA SHOULD ALREADY BE ACTIVATED.
Special weather statement, Apr 20, 7:30 PM CDT, 30 minutes before
OKZ054>076-ARZ001-002-010-011-019-029-211200- EASTERN OKLAHOMA/NORTHWEST ARKANSAS THUNDERSTORM OUTLOOK...UPDATED NATIONAL WEATHER SERVICE TULSA OK 730 PM CDT SUN APR 20 1997 NUMEROUS SEVERE THUNDERSTORMS ARE EXPECTED THIS EVENING IN SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. THE RISK OF SEVERE STORMS IS SOUTHEAST OF A LINE FROM JAY TO OKEMAH. SEVERE WEATHER WATCHES ARE IN EFFECT FOR THIS AREA UNTIL LATE EVENING. A LINE OF STRONG TO SEVERE THUNDERSTORMS HAS ALREADY DEVELOPED ACROSS EASTERN OKLAHOMA EARLY THIS EVENING. NUMEROUS SEVERE THUNDERSTORM WARNINGS WERE IN EFFECT AS OF 730 PM ALONG THIS LINE. THE STORMS HAVE DEVELOPED JUST AHEAD OF A COLD FRONT WHICH WAS MOVING INTO THE AREA. THE STORMS ARE EXPECTED TO REMAIN SEVERE THIS EVENING AS THEY MOVE ACROSS SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. THE GREATEST SEVERE WEATHER THREAT FROM THESE STORMS WILL BE LARGE HAIL AND DAMAGING WINDS. WIND PROFILES ARE A BIT MORE FAVORABLE FOR TORNADIC STORMS IN CARROLL AND MADISON COUNTIES OF NORTHWEST ARKANSAS. CURRENT RADAR INDICATIONS SUGGEST A WEAKNESS IN THE THUNDERSTORM LINE THAT IS APPROACHING EXTREME NORTHWEST ARKANSAS BUT SHOULD THE STORMS IN THIS PORTION OF THE LINE INTENSIFY...THE POTENTIAL WOULD EXIST FOR AN ISOLATED TORNADO IN CARROLL OR MADISON COUNTIES THIS EVENING. THE STORMS SHOULD BE EAST OF THE AREA BY MIDNIGHT AND THE SEVERE WEATHER THREAT WILL END BY THAT TIME. EMERGENCY MANAGEMENT AGENCIES AND SKYWARN GROUPS IN THE RISK AREA SHOULD ALREADY BE ACTIVATED.
The office that day
Everything else NWS Tulsa, OK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 7:01 PM CDT | Severe Thunderstorm Warning | TSA | Cherokee | 59 min |
| Apr 20, 7:09 PM CDT | Severe Thunderstorm Warning | TSA | McIntosh | 51 min |
| Apr 20, 7:26 PM CDT | Severe Thunderstorm Warning | TSA | Muskogee | 49 min |
| Apr 20, 8:13 PM CDT | Severe Thunderstorm Warning | TSA | Cherokee, Muskogee | 47 min |
| Apr 20, 8:54 PM CDT | Severe Thunderstorm Warning | TSA | Sequoyah | 51 min |
| Apr 20, 9:11 PM CDT | Severe Thunderstorm Warning | TSA | Muskogee | 34 min |
| Apr 20, 9:39 PM CDT | Severe Thunderstorm Warning | TSA | Sequoyah | 36 min |
| Apr 20, 10:13 PM CDT | Severe Thunderstorm Warning | TSA | LeFlore, Sequoyah | 47 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.