Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 91, NWS Tulsa, OK

April 4, 1999Adair County, Sequoyah County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Apr 4, 1999, 7:10 PM CDT for Adair County, Sequoyah County, Oklahoma. It was in force for 35 min. 2 reports 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 4, 1999, 7:10 PM CDT (00:10 UTC)
Expired: Apr 4, 1999, 7:45 PM CDT
In force: 35 min
Issued by: NWS Tulsa, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Adair County, OK, Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 59 km from the middle of the area, began a volume at 00:09 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 4, 7:20 PM CDT	Hail 1	Marble City, OK
Apr 4, 7:48 PM CDT	Hail 1	Stilwell, 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 nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 0.2 hours before the alert went out and 161 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: 2947 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 201 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.

999 
WUUS54 KTSA 050011 RRA
SVRTUL
OKC001-135-050045-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
710 PM CDT SUN APR 4 1999

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ADAIR COUNTY IN EAST CENTRAL OKLAHOMA
  NORTHERN SEQUOYAH COUNTY IN EAST CENTRAL OKLAHOMA

* UNTIL 745 PM CDT

* AT 710 PM CDT A SEVERE THUNDERSTORM WAS LOCATED 3 MILES SOUTHWEST
  OF MARBLE CITY...MOVING NORTHEAST AT 45 MPH.

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...  MARBLE
  CITY...BRUSHY...SALLISAW...WESTVILLE...CHRISTIE...BARON...BUNCH AND
  STILWELL

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

THIS IS A DANGEROUS STORM. IF YOU ARE NEAR ITS PATH YOU SHOULD
PREPARE FOR VERY LARGE HAIL AND STRONG DAMAGING STRAIGHT LINE WINDS.
SEEK SHELTER IN A STURDY BUILDING AND STAY AWAY FROM WINDOWS

LAT...LON 3550 9498 3543 9478 3596 9447 3605 9473

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 4, 3:55 PM CDT, 3 hours 15 minutes earlier.

Area forecast discussion, Apr 4, 3:55 PM CDT, 3 hours 15 minutes before

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
355 PM CDT SUN APR 4 1999

PROBLEMS OF THE DAY:
WILL THERE BE SEVERE CONVECTION?
WILL THE CONVECTION BE SCATTERED OR NUMEROUS?
WHAT TYPE(S) OF SEVERE WEATHER WILL OCCUR?
TEMPERATURES

LOOKS LIKE A LONG NEXT 24 HOURS AHEAD OF US AS ANOTHER MAJOR SEVERE
WEATHER EVENT UNFOLDS ACROSS THE COUNTY WARNING AREA.

INGREDIENTS ALREADY COMING TOGETHER AS PLANNED LATE THIS AFTERNOON
WITH THE AVN MODEL LOOKING RIGHT ON TARGET SO WILL CONTINUE TO
UTILIZE THIS MODEL FOR THE DETAILS. DEEPER MOISTURE EVIDENT ON
VISIBLE SATELLITE IMAGERY IS SURGING NORTH INTO SOUTHEAST OKLAHOMA
NOW AND SHOULD OVERSPREAD THE AREA THIS EVENING. WARM FRONT ACROSS
TEXAS AND LOUISIANA WILL CONTINUE LIFTING NORTH OVERNIGHT AS WELL.

GOOD ACCAS FIELD PRESENT IN STRONG ISENTROPIC LIFT ACROSS NORTHERN
AND WESTERN OKLAHOMA AT THIS TIME WITH A FEW SHOWERS AND EVEN
ISOLATED EMBEDDED THUNDERSTORMS OCCURRING WITHIN THIS AREA.
CONVECTION SHOULD REALLY TAKE OFF THIS EVENING AS THE DEEPER MOISTURE
OVERSPREADS THIS AREA OF STRONG ISENTROPIC LIFT. ALREADY SEEING
STRONG STORMS APPROCHING FAR SOUTHEAST OKLAHOMA AT THIS TIME.

WE MAY SEE A TEMPORARY BREAK IN THE ACTION FOR A FEW HOURS LATER
TONIGHT OR AT LEAST SEE THE COVERAGE OF STORMS DIMINISH. HOWEVER AS
THE UPPER SYSTEM HEADS OUR WAY AND SURFACE LOW ORGANIZES TO OUR
WEST...A SHARPENING DRYLINE WILL BEGIN TO PUNCH OUT OF THE PANHANDLES
AND A SQUALL LINE WILL DEVELOP ALONG THIS FEATURE LATER TONIGHT. THE
SQUALL LINE SHOULD BE ENTERING OUR AREA BY AROUND 12Z GIVE OR TAKE A
COUPLE HOURS AND WILL THEN MARCH ACROSS THE AREA DURING THE DAY
MONDAY.

WIND PROFILES ARE QUITE IMPRESSIVE WITH THIS SYSTEM...MUCH MORE SO
THAN THEY WERE WITH THE SYSTEM YESTERDAY. SO SUPERCELLULAR STORMS AND
STORM ROTATION WILL BE A GOOD BET WITH ANY STORMS AHEAD OF THE SQUALL
LINE AND WITH ANY LEWPS EMBEDDED IN THE SQUALL LINE. INSTABILITY
LOOKS TO BE SLIGHTLY LESS THAN WITH THE PREVIOUS SYSTEM BUT STILL
MORE THAN SUFFICIENT GIVEN THE STRONG DYNAMICS.

SKIES SHOULD CLEAR RAPIDLY LATE MONDAY OR MONDAY EVENING AND THEN
TRANQUIL WEATHER WILL PREVAIL UNTIL THE NEXT MAJOR SYSTEM BEGINS
AFFECTING US LATER WEDNESDAY NIGHT. SINCE THE EFFECTS OF THIS SYSTEM
WILL NOT BE FELT UNTIL AFTER THE SUN HAS SET WEDNESDAY...WILL ONLY
INCLUDE POPS IN THE THURSDAY PORTION OF THE EXTENDED.

GUIDANCE TEMPERATURES TOO COOL TONIGHT BUT REASONABLE THEREAFTER. AVN
MOS POPS ARE FAR SUPERIOR TO THE NGM MOS AS THE NGM IS DOING A WOEFUL
JOB WITH THE MOISTURE RETURN. AVN POPS ARE TOO LOW MONDAY THOUGH.

FCSTID = 5
TUL   59  68  46  74 / 100 100   0   0
FSM   61  74  47  76 / 100 100  10   0
MLC   62  69  45  76 / 100 100   0   0
BVO   58  68  46  74 / 100 100   0   0
FYV   57  70  44  72 / 100 100  10   0
IDB   65  76  48  77 / 100 100  10   0
BYV   56  71  44  72 / 100 100  10   0
MIO   57  69  44  72 / 100 100   0   0
MKO   59  70  46  74 / 100 100   0   0
F10   59  68  46  74 / 100 100   0   0
HHW   64  76  47  77 / 100 100  10   0

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

PLATE

--------------------
EXPERIMENTAL OUTPUT:

HAZARDOUS WEATHER EXPECTED NEXT 24 HOURS: CHANCE SEVERE THUNDERSTORMS
NGM CONFIDENCE:  6 ON A SCALE OF 0 TO 10
ETA CONFIDENCE:  8 ON A SCALE OF 0 TO 10
AVN CONFIDENCE:  8 ON A SCALE OF 0 TO 10
FCST CONFIDENCE: 8 ON A SCALE OF 0 TO 10

In the hours before

Local storm report, Apr 4, 4:27 PM CDT, 2 hours 43 minutes before

PRELIMINARY LOCAL STORM REPORT...COR TIME ZONE
NATIONAL WEATHER SERVICE TULSA OK
427 PM CDT SUN APR 04 1999

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

0400 AM    ALMA                      AR   1 INCH HAIL
04/03/99   CRAWFORD                       SOME HAIL GREATER THAN 1
                                          INCH

0130 PM    ROGERS                    AR   WIND DAMAGE
04/03/99   BENTON                         NUMEROUS LARGE LIMBS
                                          BLOWN DOWN

Local storm report, Apr 4, 5:27 PM CDT, 1 hour 43 minutes before

PRELIMINARY LOCAL STORM REPORT...COR TIME ZONE
NATIONAL WEATHER SERVICE TULSA OK
527 PM CDT SUN APR 04 1999

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

0450 PM    FROGVILLE                 OK   1 INCH HAIL
04/04/99   CHOCTAW

Local storm report, Apr 4, 5:27 PM CDT, 1 hour 43 minutes before

PRELIMINARY LOCAL STORM REPORT...COR TIME ZONE
NATIONAL WEATHER SERVICE TULSA OK
527 PM CDT SUN APR 04 1999

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

0450 PM    FROGVILLE                 OK   1 INCH HAIL
04/04/99   CHOCTAW

Local storm report, Apr 4, 5:32 PM CDT, 1 hour 38 minutes before

PRELIMINARY LOCAL STORM REPORT...COR TIME ZONE
NATIONAL WEATHER SERVICE TULSA OK
427 PM CDT SUN APR 04 1999

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

0400 AM    ALMA                      AR   1 INCH HAIL
04/03/99   CRAWFORD                       SOME HAIL GREATER THAN 1
                                          INCH

0130 PM    ROGERS                    AR   WIND DAMAGE
04/03/99   BENTON                         NUMEROUS LARGE LIMBS
                                          BLOWN DOWN

Local storm report, Apr 4, 6:56 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
556 PM CST SUN APR 04 1999

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

0415 PM    CLOUDY                    OK   .75 INCH HAIL
04/04/99   PUSHMATAHA

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 4, 7:42 PM CDT	Severe Thunderstorm Warning	TSA	Adair	33 min
Apr 5, 7:30 AM CDT	Severe Thunderstorm Warning	TSA	Okfuskee	45 min
Apr 5, 8:01 AM CDT	Severe Thunderstorm Warning	TSA	McIntosh, Okmulgee	44 min
Apr 5, 10:51 AM CDT	Severe Thunderstorm Warning	TSA	Adair, Sequoyah	39 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 1999 Every severe thunderstorm warning in 1999

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.