Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 92, NWS Tulsa, OK

April 20, 2000Crawford County, Arkansas; Adair County, Sequoyah County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Apr 20, 2000, 1:21 AM CDT for Crawford County, Arkansas; Adair County, Sequoyah County, Oklahoma. It was in force for 54 min. 1 report came from 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, with what was reported inside it.

The facts

Issued: Apr 20, 2000, 1:21 AM CDT (06:21 UTC)
Expired: Apr 20, 2000, 2:15 AM CDT
In force: 54 min
Issued by: NWS Tulsa, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Crawford County, AR, Adair County, OK, Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 35 km from the middle of the area, began a volume at 06:22 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, 1:56 AM CDT	Hail 0.75	Alma, AR

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, 12:30 AM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 6.4 hours before the alert went out and 155 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: 1428 J/kg
Mixed-layer CIN: -113 J/kg
Mixed-layer LCL: 1062 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 131 m²/s²
0-3 km storm-relative helicity: 247 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 12.7

Open this sounding in Storm Lab

The text

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

000 
WUUS54 KTSA 200622
SVRTUL
ARC033-OKC001-135-200715-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
121 AM CDT THU APR 20 2000

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN SEQUOYAH COUNTY IN EAST CENTRAL OKLAHOMA
  SOUTHERN ADAIR COUNTY IN NORTHEAST OKLAHOMA
  CRAWFORD COUNTY IN NORTHWEST ARKANSAS

* UNTIL 215 AM CDT

* AT 121 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SEVERE THUNDERSTORMS ALONG A LINE EXTENDING FROM 12 MILES NORTHWEST
  OF NATURAL DAM TO 4 MILES NORTHEAST OF BRUSHY TO 3 MILES SOUTHWEST
  OF GANS...MOVING EAST AT 40 MPH.

* SOME LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...LEE CREEK...
RUDY...FIGURE FIVE...DYER...CHESTER...NATURAL DAM...CEDARVILLE...
ALMA...VAN BUREN...MOUNTAINBURG...MULBERRY...MOFFETT...SHORT...
BRUSHY...ROLAND...MULDROW...GANS AND SALLISAW

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. TORNADOES CAN DEVELOP SUDDENLY
FROM SEVERE THUNDERSTORMS. BE ALERT FOR RAPIDLY CHANGING WEATHER
CONDITIONS.

CALL 1-800-722-2778 TO REPORT SEVERE WEATHER TO THE NATIONAL WEATHER
SERVICE.

LAT...LON 3577 9461 3559 9475 3529 9490 3545 9406
          3559 9401 3574 9397

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 19, 9:22 PM CDT, 3 hours 59 minutes earlier.

Area forecast discussion, Apr 19, 9:22 PM CDT, 3 hours 59 minutes before

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
922 PM CDT WED APR 19 2000

CAPPING INVERSION AND WEAK CONVERGENCE ALONG DRYLINE HAS KEPT
BOUNDARY-LAYER BASED CONVECTION FROM DEVELOPING ACROSS THE FORECAST
AREA SO FAR THIS EVENING. SURFACE OBSERVATIONS AND SATELLITE IMAGERY
SHOW THE DRYLINE EXTENDING FROM SOUTHEAST KANSAS ACROSS THE
NORTHWEST CORNER OF OSAGE COUNTY TO JUST NORTHWEST OF KOKC.  SURFACE
COLD FRONT WAS SURGING RAPIDLY SOUTHEAST ACROSS CENTRAL KANSAS AND
NORTHWEST OKLAHOMA.

EVENING UPPER AIR ANALYSIS INDICATED AN UPPER LEVEL SPEED MAX MOVING
NORTHEAST ACROSS TEXAS PANHANDLE. RAPID DEVELOPMENT OF CLOUDS IN
NORTHWEST OKLAHOMA SUGGESTS THAT LIFT ASSOCIATED WITH THE SPEED MAX
WAS SPREADING EAST.

STILL EXPECT AT LEAST SCATTERED SEVERE STORMS TO AFFECT THE FORECAST
AREA TONIGHT. CURRENT INDICATIONS ARE THAT CONVECTION MAY INITIALLY
FIRE TO THE WEST BETWEEN 10 AND 11 PM AS COLD FRONT CATCHES UP TO
DRYLINE AND STRONG INSTABILITY IS RELEASED. THE UPPER SPEED MAX WILL
PROVIDE THE LIFT/DYNAMICS TO KEEP THE STORMS GOING WELL INTO THE
NIGHT AS CONVECTION MOVES ACROSS THE AREA.

THERE ARE STILL SOME UNCERTAINTIES REGARDING COVERAGE OF STORMS
TONIGHT...SO I PREFER NOT TO ADJUST FIRST PERIOD OF FORECAST AT THIS
TIME. HOWEVER...IF STORMS DO INDEED FIRE ALONG THE COLD FRONT AS
EXPECTED...WILL THEN ISSUE AN UPDATE TO RAISE POPS TO CATEGORICAL IN
SOME AREAS WITH POTENTIAL FOR RAPIDLY MOVING SQUALL LINE.

FCSTID = 9

.TUL...
AR...NONE.
OK...NONE.

In the hours before

Local storm report, Apr 19, 11:28 PM CDT, 1 hour 53 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
1128 PM CDT WED APR 19 2000

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1120 PM    BEGGS                     OK    1 INCH HAIL
04/19/00   OKMULGEE                        PUBLIC REPORT OF
                                           QUARTER SIZED HAIL.

DRM

Local storm report, Apr 20, 12:11 AM CDT, 1 hour 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
1211 AM CDT THU APR 20 2000

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1156 PM    BIXBY                     OK    70 MPH TSTM GUST
04/19/00   TULSA                           60 TO 70 MPH WINDS
                                           REPORTED BY OFF DUTY
                                           NWS EMPLOYEE.
h

DRM

Local storm report, Apr 20, 12:39 AM CDT, 42 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
1239 AM CDT THU APR 20 2000

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1200 AM    2 N HASKELL               OK    1.75 INCH HAIL
04/20/00   MUSKOGEE                        PUBLIC REPORT OF
                                           GOLFBALL HAIL.

DRM

Local storm report, Apr 20, 12:51 AM CDT, 30 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
1251 AM CDT THU APR 20 2000

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....
(
1212 AM    OKAY                      OK    75 MPH TSTM GUST
04/20/00   WAGONER                         FIRE DEPT. REPORT

DRM

Special weather statement, Apr 20, 12:55 AM CDT, 26 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
1255 AM CDT THU APR 20 2000

OKZ054-055-059-200900-
A TORNADO WATCH IS NO LONGER IN EFFECT FOR THE FOLLOWING COUNTIES IN

EASTERN OKLAHOMA.
         PAWNEE              WASHINGTON OK       OSAGE

OKZ049-053-056>058-060>075-200900-
A TORNADO WATCH REMAINS IN EFFECT UNTIL 400 AM CDT THURSDAY FOR THE
FOLLOWING COUNTIES IN

EASTERN OKLAHOMA...
         ADAIR               CHEROKEE            CHOCTAW
         CRAIG               CREEK               DELAWARE
         HASKELL             LATIMER             MAYES
         MCINTOSH            MUSKOGEE            NOWATA
         OTTAWA              OKFUSKEE            OKMULGEE
         PITTSBURG           PUSHMATAHA          ROGERS
         SEQUOYAH            TULSA               WAGONER

Special weather statement, Apr 20, 1:18 AM CDT, 3 minutes before

ZCZC WRKWG2
TTAA00 KOKC DDHHMM

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
118 AM CDT THU APR 20 2000

OKZ056-060>061-064>066-200900-
A TORNADO WATCH IS NO LONGER IN EFFECT FOR THE FOLLOWING COUNTIES IN

EASTERN OKLAHOMA.
         CREEK               OKFUSKEE
         TULSA               OKMULGEE
         NOWATA              ROGERS

OKZ049-053-057-058-062-063-067>075-200900-
A TORNADO WATCH REMAINS IN EFFECT UNTIL 400 AM CDT THURSDAY FOR THE
FOLLOWING COUNTIES IN

EASTERN OKLAHOMA...
         ADAIR               CHEROKEE            CHOCTAW
         CRAIG               DELAWARE            HASKELL
 =        LATIMER             MAYES               MCINTOSH
         MUSKOGEE            OTTAWA              PITTSBURG
         PUSHMATAHA          SEQUOYAH            WAGONER

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 12:58 AM CDT	Severe Thunderstorm Warning	TSA	Benton, Washington	62 min
Apr 20, 1:37 AM CDT	Severe Thunderstorm Warning	TSA	Carroll, Madison	38 min
Apr 20, 2:00 AM CDT	Severe Thunderstorm Warning	TSA	Franklin	45 min
Apr 20, 2:14 AM CDT	Severe Thunderstorm Warning	TSA	Madison	31 min
Apr 19, 10:22 PM CDT	Severe Thunderstorm Warning	TSA	Osage, Pawnee	38 min
Apr 19, 10:33 PM CDT	Severe Thunderstorm Warning	TSA	Creek, Okfuskee	42 min
Apr 19, 11:02 PM CDT	Severe Thunderstorm Warning	TSA	Osage, Pawnee, Washington	58 min
Apr 19, 11:06 PM CDT	Severe Thunderstorm Warning	TSA	Okfuskee, Okmulgee	54 min
Apr 19, 11:14 PM CDT	Severe Thunderstorm Warning	TSA	Creek	46 min
Apr 19, 11:29 PM CDT	Severe Thunderstorm Warning	TSA	Okmulgee, Tulsa, Wagoner	61 min
Apr 19, 11:29 PM CDT	Severe Thunderstorm Warning	TSA	Muskogee	61 min
Apr 19, 11:37 PM CDT	Severe Thunderstorm Warning	TSA	Nowata	38 min
Apr 19, 11:46 PM CDT	Tornado Warning	TSA	Muskogee, Wagoner	44 min
Apr 19, 11:59 PM CDT	Severe Thunderstorm Warning	TSA	Rogers, Tulsa	46 min
Apr 19, 11:59 PM CDT	Severe Thunderstorm Warning	TSA	Creek	46 min
Apr 20, 12:01 AM CDT	Severe Thunderstorm Warning	TSA	Craig, Ottawa	59 min
Apr 20, 12:17 AM CDT	Severe Thunderstorm Warning	TSA	Cherokee, Mayes, Muskogee	58 min
Apr 20, 12:23 AM CDT	Severe Thunderstorm Warning	TSA	McIntosh, Pittsburg	52 min
Apr 20, 12:40 AM CDT	Severe Thunderstorm Warning	TSA	Haskell, Muskogee, Sequoyah	65 min
Apr 20, 12:44 AM CDT	Severe Thunderstorm Warning	TSA	Adair, Delaware	46 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2000 Severe Thunderstorm Warnings in Arkansas, 2000 Every severe thunderstorm warning in 2000

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.