Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 87, NWS Tulsa, OK

April 20, 2000Cherokee County, Mayes County, Muskogee County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Apr 20, 2000, 12:17 AM CDT for Cherokee County, Mayes County, Muskogee County, Oklahoma. It was in force for 58 min. 3 reports 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, 2000, 12:17 AM CDT (05:17 UTC)
Expired
Apr 20, 2000, 1:15 AM CDT
In force
58 min
Issued by
NWS Tulsa, OK
Area
Whole counties

Counties Cherokee County, OK, Mayes County, OK, Muskogee County, OK

What was reported inside it

TimeReportWhereRemark
Apr 20, 12:30 AM CDTThunderstorm Wind 52 ESalina, OK
Apr 20, 12:32 AM CDTThunderstorm WindMuskogee, OKThunderstorm winds blew down several trees.
Apr 20, 12:55 AM CDTThunderstorm WindTahlequah, OKThunderstorm winds blew down several large trees.

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.

IssuedProductOfficeLasted
Apr 19, 10:15 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 5.3 hours before the alert went out and 165 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, Springfield, MO at 00:00Z on 2000-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1428 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 00:00Z on 2000-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 square meters per square second.19395878Sfc1 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
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 200518
SVRTUL
OKC021-097-101-200615-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
1217 AM CDT THU APR 20 2000

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CHEROKEE COUNTY IN EAST CENTRAL OKLAHOMA
  MUSKOGEE COUNTY IN EAST CENTRAL OKLAHOMA
  SOUTHERN MAYES COUNTY IN NORTHEAST OKLAHOMA

* UNTIL 115 AM CDT

* AT 1217 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SEVERE THUNDERSTORMS ALONG A LINE EXTENDING FROM 2 MILES SOUTHWEST
  OF LOCUST GROVE TO 2 MILES EAST OF MUSKOGEE TO 3 MILES SOUTH OF
  OKTAHA...MOVING EAST AT 40 MPH.

* SOME LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...WEBBERS
FALLS...FORT GIBSON...BRAGGS...KEEFETON...OKTAHA...WARNER...
MUSKOGEE...ROSE...LOCUST GROVE...SCRAPER...PEGGS...HULBERT...
COOKSON...TAHLEQUAH AND OAKS

HAIL TO THE SIZE OF DIMES AND WIND GUSTS TO 60 MPH CAN BE EXPECTED IN
THE WARNED AREA.

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

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, 2 hours 55 minutes earlier.

Area forecast discussion, Apr 19, 9:22 PM CDT, 2 hours 55 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

Special weather statement, Apr 19, 9:45 PM CDT, 2 hours 32 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-201200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
945 PM CDT WED APR 19 2000

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED LATE TONIGHT THROUGH
EARLY THURSDAY MORNING ACROSS EASTERN OKLAHOMA AND NORTHWEST
ARKANSAS...

.SYNOPSIS...
SURFACE LOW PRESSURE WAS LOCATED OVER NORTHEAST NEBRASKA THIS
EVENING. THE DRYLINE EXTENDED SOUTH FROM THE LOW THROUGH EASTERN
KANSAS INTO CENTRAL OKLAHOMA. THE DRYLINE WAS RETREATING TO THE
WEST...AS A STRONG COLD FRONT WAS RAPIDLY ADVANCING SOUTHEAST ACROSS
NORTHWEST OKLAHOMA. THE INTERSECTION OF THE COLD FRONT AND THE
DRYLINE WILL RESULT IN SCATTERED SEVERE THUNDERSTORMS LATE THIS
EVENING ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS.

.PRIMARY HAZARD...
SEVERE THUNDERSTORMS ARE STILL EXPECTED TO DEVELOP ACROSS EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS LATE TONIGHT. THE MAIN THREAT FROM
THESE STORMS WILL BE LARGE HAIL...AND DAMAGING STRAIGHT LINE WINDS.
IN ADDITION...ISOLATED TORNADOES MAY ALSO DEVELOP DUE TO SUFFICIENT
SHEAR.

.DISCUSSION...
VERY WARM AIR ALOFT KEPT THUNDERSTORMS FROM FIRING UP MOST OF THE DAY
ACROSS OKLAHOMA AND ARKANSAS. THE CAP DID BREAK IN SOME LOCATIONS
THIS AFTERNOON AND EARLY EVENING...MAINLY ACROSS EASTERN KANSAS AND
WESTERN MISSOURI. SOME ELEVATED CONVECTION ALSO DEVELOPED ACROSS
NORTHWEST ARKANSAS. HOWEVER EVENING SOUNDINGS AT 7 PM REVEALED THE
ENVIRONMENT WAS TOO WARM AT MID LEVELS TO SUPPORT SURFACE BASED
THUNDERSTORMS...DESPITE INCREASING INSTABILITY.

STORMS ARE EXPECTED TO DEVELOP LATE TONIGHT ACROSS NORTH CENTRAL
OKLAHOMA...AS THE RETREATING DRYLINE MERGES WITH THE ADVANCING COLD
FRONT. THIS WILL PROVIDE THE LIFT NECESSARY TO INITIATE
THUNDERSTORMS. GIVEN THE UNSTABLE ENVIRONMENT THESE STORMS WILL MOVE
INTO...IT IS LIKELY THE STORMS WILL QUICKLY BECOME SEVERE.

.SPOTTER ACTIVATION...
SPOTTERS ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS SHOULD BE
PREPARED FOR ACTIVATION TONIGHT.  THE MOST LIKELY TIME FOR
ACTIVATION WILL BE BETWEEN 11 PM AND 1 AM IN EASTERN OKLAHOMA AND 2
AM AND 5 AM OVER NORTHWEST ARKAENSAS.
Local storm report, Apr 19, 11:28 PM CDT, 49 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, 6 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

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 19, 10:22 PM CDTSevere Thunderstorm WarningTSAOsage, Pawnee38 min
Apr 19, 10:33 PM CDTSevere Thunderstorm WarningTSACreek, Okfuskee42 min
Apr 19, 11:02 PM CDTSevere Thunderstorm WarningTSAOsage, Pawnee, Washington58 min
Apr 19, 11:06 PM CDTSevere Thunderstorm WarningTSAOkfuskee, Okmulgee54 min
Apr 19, 11:14 PM CDTSevere Thunderstorm WarningTSACreek46 min
Apr 19, 11:29 PM CDTSevere Thunderstorm WarningTSAOkmulgee, Tulsa, Wagoner61 min
Apr 19, 11:29 PM CDTSevere Thunderstorm WarningTSAMuskogee61 min
Apr 19, 11:37 PM CDTSevere Thunderstorm WarningTSANowata38 min
Apr 19, 11:46 PM CDTTornado WarningTSAMuskogee, Wagoner44 min
Apr 19, 11:59 PM CDTSevere Thunderstorm WarningTSARogers, Tulsa46 min
Apr 19, 11:59 PM CDTSevere Thunderstorm WarningTSACreek46 min
Apr 20, 12:01 AM CDTSevere Thunderstorm WarningTSACraig, Ottawa59 min
Apr 20, 12:23 AM CDTSevere Thunderstorm WarningTSAMcIntosh, Pittsburg52 min
Apr 20, 12:40 AM CDTSevere Thunderstorm WarningTSAHaskell, Muskogee, Sequoyah65 min
Apr 20, 12:44 AM CDTSevere Thunderstorm WarningTSAAdair, Delaware46 min
Apr 20, 1:21 AM CDTSevere Thunderstorm WarningTSAAdair, Sequoyah54 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2000Every 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.