Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 206, NWS Tulsa, OK

May 11, 1999Mayes County, Rogers County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at May 11, 1999, 6:12 PM CDT for Mayes County, Rogers County, Oklahoma. It was in force for 48 min. 5 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: May 11, 1999, 6:12 PM CDT (23:12 UTC)
Expired: May 11, 1999, 7:00 PM CDT
In force: 48 min
Issued by: NWS Tulsa, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Mayes County, OK, Rogers County, OK

The radar

The Tulsa radar (KINX), 22 km from the middle of the area, began a volume at 23:14 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, 6:21 PM CDT	Hail 0.75	Pryor, OK	There were several reports of dime-sized hail near Pryor.
May 11, 6:26 PM CDT	Hail 2.75	Pryor, OK	At 627 PM CDT, there was a report of golfball-sized hail 5 miles west of Pryor. At 635 PM CDT, there was a report of quarter-size (1" diameter) hail 5 miles west of Pryor. At 640 PM CDT, there was a report of baseball-sized hail 2 miles west of Pryor.
May 11, 6:48 PM CDT	Hail 1	Pryor, OK	There were several reports of dime and quarter-sized hail southwest of Pryor.
May 11, 6:50 PM CDT	Hail 0.75	Inola, OK
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.

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 12:00Z, 11.2 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

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 May 11, 3:45 PM CDT, 2 hours 27 minutes earlier.

Area forecast discussion, May 11, 3:45 PM CDT, 2 hours 27 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

Special weather statement, May 11, 1:00 PM CDT, 5 hours 12 minutes before

ARZ001-002-010-011-019-020-029-OKZ049-053>076-121100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
100 PM CDT TUE MAY 11 1999

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED ACROSS EASTERN OKLAHOMA
   AND NORTHWEST ARKANSAS TONIGHT...

.SYNOPSIS...
A COLD FRONT WAS LOCATED FROM NORTHWEST OF BARTLESVILLE TO WEST OF
ARDMORE EARLY THIS AFTERNOON. THE FRONT WILL MOVE SLOWLY EAST THROUGH
TONIGHT AND WILL EXTEND FROM NORTHWEST ARKANSAS INTO SOUTHEAST OKLAHOMA
BY SUNRISE WEDNESDAY. AN UPPER LEVEL TROUGH OF LOW PRESSURE WAS LOCATED
ACROSS EASTERN NEW MEXICO AND WILL MOVE EAST INTO OKLAHOMA TONIGHT.
THE COLD FRONT WILL BE A FOCUS FOR THUNDERSTORM DEVELOPMENT LATE THIS
AFTERNOON OR THIS EVENING AS THE UPPER LEVEL TROUGH APPROACHES. A FEW
SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG OR AHEAD OF THE COLD
FRONT THROUGH TONIGHT.

.DISCUSSION...
A CAP OF WARM AIR ALOFT WILL INHIBIT THUNDERSTORM DEVELOPMENT FOR MOST
OF THE AFTERNOON HOURS. AS COLDER AIR ALOFT MOVES INTO THE AREA THIS
EVENING AND OVERNIGHT...THUNDERSTORMS WILL GRADUALLY BECOME MORE
NUMEROUS NEAR THE FRONT.

A MODERATELY UNSTABLE AIRMASS WILL LEAD TO A FEW SEVERE THUNDERSTORMS
THIS EVENING AND OVERNIGHT AS STRENGTHENING WINDS ALOFT ACT TO ORGANIZE
DEVELOPMENT. ALTHOUGH WIND FIELDS ARE NOT EXPECTED TO BE IDEAL FOR
SUPERCELLS...A FEW ROTATING THUNDERSTORMS WILL BE POSSIBLE ACROSS
EASTERN OKLAHOMA THIS EVENING. THE PRIMARY MODE OF SEVERE CONVECTION
OVERNIGHT IS EXPECTED TO BE BOW ECHO LINE SEGMENTS.

LARGE HAIL AND DAMAGING STRAIGHT LINE WINDS WILL BE POSSIBLE WITH
SEVERE THUNDERSTORMS TONIGHT. CONVECTION WILL LIKELY ORGANIZE INTO A
COMPLEX OF MULTICELL THUNDERSTORMS BY MIDNIGHT AND MOVE EAST ACROSS
THE AREA OVERNIGHT. LOCALLY HEAVY RAINS CAN BE EXPECTED AS
THUNDERSTORMS CONTINUE TO DEVELOP AND MOVE NORTHEAST ALONG THE SLOW
MOVING FRONT.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
EMERGENCY MANAGEMENT AGENCIES AND STORM SPOTTER GROUPS IN EASTERN
OKLAHOMA SHOULD BE PREPARED FOR ACTIVATION BY 7 PM.  STORM SPOTTER
ACTIVATION MAY BE NEEDED IN NORTHWEST ARKANSAS AFTER 10 PM.

Special weather statement, May 11, 1:00 PM CDT, 5 hours 12 minutes before

ARZ001-002-010-011-019-020-029-OKZ049-053>076-121100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
100 PM CDT TUE MAY 11 1999

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED ACROSS EASTERN OKLAHOMA
   AND NORTHWEST ARKANSAS TONIGHT...

.SYNOPSIS...
A COLD FRONT WAS LOCATED FROM NORTHWEST OF BARTLESVILLE TO WEST OF
ARDMORE EARLY THIS AFTERNOON. THE FRONT WILL MOVE SLOWLY EAST THROUGH
TONIGHT AND WILL EXTEND FROM NORTHWEST ARKANSAS INTO SOUTHEAST OKLAHOMA
BY SUNRISE WEDNESDAY. AN UPPER LEVEL TROUGH OF LOW PRESSURE WAS LOCATED
ACROSS EASTERN NEW MEXICO AND WILL MOVE EAST INTO OKLAHOMA TONIGHT.
THE COLD FRONT WILL BE A FOCUS FOR THUNDERSTORM DEVELOPMENT LATE THIS
AFTERNOON OR THIS EVENING AS THE UPPER LEVEL TROUGH APPROACHES. A FEW
SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG OR AHEAD OF THE COLD
FRONT THROUGH TONIGHT.

.DISCUSSION...
A CAP OF WARM AIR ALOFT WILL INHIBIT THUNDERSTORM DEVELOPMENT FOR MOST
OF THE AFTERNOON HOURS. AS COLDER AIR ALOFT MOVES INTO THE AREA THIS
EVENING AND OVERNIGHT...THUNDERSTORMS WILL GRADUALLY BECOME MORE
NUMEROUS NEAR THE FRONT.

A MODERATELY UNSTABLE AIRMASS WILL LEAD TO A FEW SEVERE THUNDERSTORMS
THIS EVENING AND OVERNIGHT AS STRENGTHENING WINDS ALOFT ACT TO ORGANIZE
DEVELOPMENT. ALTHOUGH WIND FIELDS ARE NOT EXPECTED TO BE IDEAL FOR
SUPERCELLS...A FEW ROTATING THUNDERSTORMS WILL BE POSSIBLE ACROSS
EASTERN OKLAHOMA THIS EVENING. THE PRIMARY MODE OF SEVERE CONVECTION
OVERNIGHT IS EXPECTED TO BE BOW ECHO LINE SEGMENTS.

LARGE HAIL AND DAMAGING STRAIGHT LINE WINDS WILL BE POSSIBLE WITH
SEVERE THUNDERSTORMS TONIGHT. CONVECTION WILL LIKELY ORGANIZE INTO A
COMPLEX OF MULTICELL THUNDERSTORMS BY MIDNIGHT AND MOVE EAST ACROSS
THE AREA OVERNIGHT. LOCALLY HEAVY RAINS CAN BE EXPECTED AS
THUNDERSTORMS CONTINUE TO DEVELOP AND MOVE NORTHEAST ALONG THE SLOW
MOVING FRONT.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
EMERGENCY MANAGEMENT AGENCIES AND STORM SPOTTER GROUPS IN EASTERN
OKLAHOMA SHOULD BE PREPARED FOR ACTIVATION BY 7 PM.  STORM SPOTTER
ACTIVATION MAY BE NEEDED IN NORTHWEST ARKANSAS AFTER 10 PM.

Local storm report, May 11, 6:04 PM CDT, 8 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, 6:04 PM CDT, 8 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, 0 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

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, 6:27 PM CDT	Tornado Warning	TSA	Mayes, Rogers	33 min
May 11, 6:53 PM CDT	Tornado Warning	TSA	Mayes	37 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.