Alert archive / Oklahoma / Tornado Warnings in 1999

Tornado Warning 61, NWS Tulsa, OK

May 11, 1999Mayes County, Oklahoma

NWS Tulsa, OK issued this tornado warning at May 11, 1999, 6:53 PM CDT for Mayes County, Oklahoma. It was in force for 37 min. 3 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: May 11, 1999, 6:53 PM CDT (23:53 UTC)
Expired: May 11, 1999, 7:30 PM CDT
In force: 37 min
Issued by: NWS Tulsa, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Mayes County, OK

The radar

The Tulsa radar (KINX), 20 km from the middle of the area, began a volume at 23:54 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
May 11, 7:07 PM CDT	Hail 0.88	Pryor, OK	There was a report of dime-sized hail 3 miles south of Pryor at 707 PM CDT, while there was a report of nickel-sized hail in Pryor at 713 PM CDT.
May 11, 7:14 PM CDT	Hail 1.75	Chouteau, OK
May 11, 7:15 PM CDT	Thunderstorm Wind	Chouteau, OK	Windows were blown out of a home northwest of Chouteau.

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
May 11, 6:15 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 11.9 hours before the alert went out and 157 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: 60 J/kg
Mixed-layer CIN: -204 J/kg
Mixed-layer LCL: 878 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 94 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 
WFUS54 KTSA 112356 RRA
TORTUL
OKC097-120030-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TULSA OK
653 PM CDT TUE MAY 11 1999

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* TORNADO WARNING FOR
  MAYES COUNTY IN NORTHEAST OKLAHOMA

* UNTIL 730 PM CDT

* AT 653 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH STRONG 
ROTATION 4 MILES WEST OF CHOUTEAU. A SECOND AREA OF ROTATION WAS 
LOCATED 2 MILES WEST OF PRYOR. THIS STORM WAS DRIFTING NORTHEAST AT 
5 MILES AN HOUR. THIS DANGEROUS STORM COULD PRODUCE A TORNADO AT ANY 
TIME.

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE... CHOUTEAU... 
LOCUST GROVE AND PRYOR

IF YOU ARE IN OR NEAR THE PATH OF THIS STORM...TAKE COVER NOW IF NO
UNDERGROUND SHELTER IS AVAILABLE MOVE TO AN INTERIOR ROOM ON THE
LOWEST FLOOR. MOBILE HOMES AND VEHICLES SHOULD BE ABANDONED FOR MORE
SUBSTANTIAL SHELTER. AVOID WINDOWS

IN ADDITION TO THE THREAT OF A TORNADO...LARGE HAIL AND DAMAGING
STRAIGHT LINE WINDS CAN BE EXPECTED WITH THIS STORM. GO TO A SAFE
PLACE NOW

LAT...LON 3626 9551 3609 9545 3615 9510 3636 9517

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at May 11, 3:45 PM CDT, 3 hours 8 minutes earlier.

Area forecast discussion, May 11, 3:45 PM CDT, 3 hours 8 minutes before

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
345 PM CDT TUE MAY 11 1999

PROBLEM(S) OF THE DAY:
WILL THERE BE SEVERE CONVECTION?
WILL THERE BE HEAVY RAINFALL?
POPS

CLOUDS HANGING TOUGH THIS AFTERNOON OVER MUCH OF THE FA...BUT
ABUNDANT SUNSHINE PREVAILED OVER FAR ERN OK AND PORTIONS OF NW
ARKANSAS. SURFACE FRONT HAS PORGRESSED AT A SNAILS PACE...WITH MID
AFTERNOON POSTIONING JUST EAST OF A KANSAS CITY TO OKLAHOMA CITY TO
WICHITA FALLS LINE. LOTS OF CLOUDS AND WARM AIR ALOFT HAS KEPT
CONVECTION IN CHECK THUS FAR. COULD STILL SEE SOME ACTIVITY FIRE
ALONG THE FRONT LATE THIS AFTERNOON...PARTICULARY IN AREAS NORTH AND
OF TUL. UPPER TROUGH STILL EXPECTED TO LIFT OUT TONIGHT BRINGING
ASSOCIATED S/W ENERGY ACROSS THE AREA. SURFACE FRONT SHOULD PROGRESS
EASTWARD IN RESPONSE TO UPPER SYSTEM LIFTING OUT. EXPECT SHOWERS AND
STORMS TO FIRE IN VICINITY OF FRONT AS THE COLDER AIR ALOFT WEAKENS
THE CAP. ACTIVITY MAY FORM INTO A COMPLEX OF STORMS AS ACTIVITY MOVES
ACROSS THE FA TONIGHT AND EARLY TOMORROW MORNING. ETA CONSISTENT WITH
PLACING ERN OK IN RIGHT ENTRANCE REGION OF H3 80 KT JET MAX. LOOKS
LIKE BEST LIFT WILL BE OVER NE OK AND NW ARKANSAS. THERE COULD ALSO
BE SOME HEAVY RAINS WITH SLOW MOVING FRONT. WILL NOT ISSUE FFA AT
THIS TIME AS MOST PRECIP IS EXPECTED OVER AREAS WHERE FFG VALUES ARE
THE HIGHEST.

FRONT EXPECTED TO BE THROUGH NW AR AND SE OK BY 12Z TOMORROW. WILL
LEAVE LOW POPS IN FOR MORNING TO COVER LINGERING ACTIVITY. DRIER AIR
ADVECTING IN BEHIND THE FRONT SHOULD RESULT IN A PARTLY CLOUDY SKY
OVER THE FA TOMORROW AFTERNOON AND NIGHT. STUCK PRETTY CLOSE TO
GUIDANCE(NGM MOS AVAILABLE) BUT OPTED FOR COOLER FAN NUMBERS IN LATER
PERIODS.

IN THE EXTENDED...WILL KEEP DRY AS MOST EXTENDED MODELS ARE
CONSISTENT WITH WEAK H5 RIDGING SETTING UP FRI AND SAT. LEE TROUGHING
WILL RESULT IN RETURN FLOW AT THE SURFACE BY FRIDAY. UPPER RIDGE
SHIFTS OFF TO THE EAST WITH SW FLOW SETTING UP AGAIN SUNDAY. THIS AND
A SURFACE DRYLINE/PACIFIC FRONT TO THE WEST OF FA WARRANTS CHANCE
POPS FOR SUNDAY.

FCSTID = 23
TUL   57  75  56  79 /  60  20   0   0
FSM   59  77  55  80 /  50  30   0   0
MLC   60  78  56  80 /  50  20   0   0
BVO   58  74  53  79 /  60  20   0   0
FYV   57  73  52  78 /  60  30   0   0
IDB   60  80  58  82 /  40  20   0   0
BYV   56  72  51  77 /  60  30   0   0
MIO   58  80  52  77 /  60  30   0   0
MKO   58  76  55  80 /  60  20   0   0
F10   57  75  56  79 /  60  20   0   0
HHW   60  80  58  82 /  40  20   0   0

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

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

HAZARDOUS WEATHER EXPECTED NEXT 24 HOURS: CHANCE SEVERE THUNDERSTORMS
NGM CONFIDENCE:  MODEL OUTPUT NOT AVAILABLE
ETA CONFIDENCE:  7 ON A SCALE OF 0 TO 10
AVN CONFIDENCE:  7 ON A SCALE OF 0 TO 10
FCST CONFIDENCE: 8 ON A SCALE OF 0 TO 10

In the hours before

Local storm report, May 11, 6:04 PM CDT, 49 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
604 PM CDT TUE MAY 11 1999

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

0601 PM    8 NW PRYOR                OK    .75 INCH HAIL
05/11/99   MAYES                           FIRE DEPT REPT OF DIME
                                           HAIL ON TURNPIKE AT
                                           MAYES/ROGERS CO. LINE

Local storm report, May 11, 6:12 PM CDT, 41 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
612 PM CDT TUE MAY 11 1999

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

0440 PM    2 W PRYOR                 OK    2.75 INCH HAIL
05/11/99   MAYES

Local storm report, May 11, 6:13 PM CDT, 40 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
613 PM CDT TUE MAY 11 1999

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

0610 PM    8 E CLAREMORE             OK    .75 INCH HAIL
05/11/99   ROGERS                          ON HWY 20...SPOTTER
                                           REPORT

Local storm report, May 11, 6:44 PM CDT, 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
612 PM CDT TUE MAY 11 1999

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

0440 PM  L  2 W PRYOR                 OK    2.75 INCH HAIL
05/11/99   MAYES

Local storm report, May 11, 6:45 PM CDT, 8 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED TIMES
NATIONAL WEATHER SERVICE TULSA OK
645 PM CDT TUE MAY 11 1999

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

0640 PM    2 W PRYOR                 OK    2.75 INCH HAIL
05/11/99   MAYES

Local storm report, May 11, 6:45 PM CDT, 8 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED TIMES
NATIONAL WEATHER SERVICE TULSA OK
645 PM CDT TUE MAY 11 1999

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

0640 PM    2 W PRYOR                 OK    2.75 INCH HAIL
05/11/99   MAYES

The office that day

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

Issued	Product	Office	Counties	Lasted
May 11, 5:40 PM CDT	Severe Thunderstorm Warning	TSA	Mayes, Rogers	35 min
May 11, 6:12 PM CDT	Severe Thunderstorm Warning	TSA	Mayes, Rogers	48 min
May 11, 6:27 PM CDT	Tornado Warning	TSA	Mayes, Rogers	33 min

Nearby

Tornado Warnings in Oklahoma, 1999 Every tornado warning in 1999 Tornadoes 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.