Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 445, NWS Tulsa, OK

August 23, 1999LeFlore County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Aug 23, 1999, 7:48 PM CDT for LeFlore County, Oklahoma. It was in force for 42 min. No storm report in the archive falls 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.

The facts

Issued: Aug 23, 1999, 7:48 PM CDT (00:48 UTC)
Expired: Aug 23, 1999, 8:30 PM CDT
In force: 42 min
Issued by: NWS Tulsa, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

County LeFlore County, OK

The radar

The Western Arkansas radar (KSRX), 60 km from the middle of the area, began a volume at 00:48 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.

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 0.8 hours before the alert went out and 246 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: 397 J/kg
Mixed-layer CIN: -157 J/kg
Mixed-layer LCL: 1204 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 72 m²/s²
0-3 km storm-relative helicity: 117 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

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

172 
WUUS54 KTSA 240049 RRA
SVRTUL
OKC079-240130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
748 PM CDT MON AUG 23 1999

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN LE FLORE COUNTY IN SOUTHEAST OKLAHOMA

* UNTIL 830 PM CDT

* AT 748 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 4 MILES SOUTHEAST OF HODGEN...MOVING EAST AT 25
  MPH.

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...HODGEN

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

LAT...LON 3488 9466 3471 9472 3453 9414 3477 9406

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 Aug 23, 3:45 PM CDT, 4 hours 3 minutes earlier.

Area forecast discussion, Aug 23, 3:45 PM CDT, 4 hours 3 minutes before

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
345 PM CDT MON AUG 23 1999

PROBLEMS OF THE DAY:
WILL THERE BE CONVECTION?
WILL THERE BE SEVERE CONVECTION?
TEMPERATURES

PLAYING A WAITING GAME NOW TO SEE IF CONVECTION FIRES NEAR THE
SURFACE LOW CENTERED OVER OSAGE COUNTY AT 20Z. WARM FRONT EXTENDS
FROM THE SURFACE LOW TO NEAR CLAREMORE THEN SOUTH TO MUSKOGEE THAN
SOUTHEAST TO NORTHERN LE FLORE COUNTY. KINX-88D HAS SHOWN THE
PROGRESS OF THE WARM FRONT QUITE NICELY THIS AFTERNOON. THIS
BOUNDARY WILL ALSO NEED TO BE WATCHED FOR POTENTIAL CONVECTIVE
DEVELOPMENT. SURFACE TROF TRAILING FROM THE LOW THROUGH SOUTHEAST
PAWNEE COUNTY INTO CENTRAL OKLAHOMA IS YET ANOTHER BOUNDARY TO
MONITOR.

THE MAIN LIMITING FACTORS FOR THUNDERSTORM DEVELOPMENT ARE THE
RELATIVE LACK OF MOISTURE AND RATHER LIMITED LOW LEVEL CONVERGENCE...
ESPECIALLY ALONG THE SURFACE TROF WHERE WINDS ARE VEERED OUT AHEAD
OF THE TROF. ALSO MID LEVEL WIND SPEEDS ARE VERY LIGHT ALTHOUGH
DIRECTIONAL SHEAR IS FAIRLY DECENT.

CONDITIONS APPEAR TO BECOME BETTER FOR CONVECTION BETWEEN 00Z AND
06Z TO THE SOUTH AND EAST OF INTERSTATE 44 AS LOW LEVEL WINDS BACK
A BIT AND MID LEVEL WINDS INCREASE SOMEWHAT. THUS ANY CONVECTION
WHICH DOES FORM MAY NOT DISSIPATE WITH THE LOSS OF HEATING BUT MAY
CONTINUE THROUGH MUCH OF THE NIGHT. COLD FRONT STILL WELL TO THE
NORTH AND WILL NOT BE A MAJOR FACTOR IN ANY CONVECTIVE ACTIVITY
TONIGHT. THIS FRONT SHOULD REACH NEAR A FORT SMITH TO MCALESTER
LINE BY MORNING.

WILL GO WITH SLIGHT CHANCE POPS FROM INTERSTATE 44 NORTH AND WEST
THIS EVENING AND ALSO SLIGHT CHANCE IN FAR SOUTHEAST OKLAHOMA. WILL
GO WITH A LITTLE HIGHER POPS IN BETWEEN WHERE CONVECTIVE PARAMETERS
APPEAR MAXIMIZED AFTER 00Z. WILL MAINTAIN LOW POPS IN FAR SOUTHEAST
OKLAHOMA TUESDAY AS FRONT SLOWS TO A CRAWL IN THAT AREA.

MUCH DRIER AIR FILTERING IN BEHIND THE FRONT ENSURES A SUNNY AND
SLIGHTLY COOLER DAY IN ALL BUT FAR SOUTHEAST OKLAHOMA TUESDAY.
MINIMAL COLD ADVECTION WILL MEAN ONLY SLIGHTLY LOWER DAYTIME
MAXIMUMS BUT MUCH DRIER AIR WILL MAKE FOR PLEASANTLY COOLER NIGHTS.

LITTLE IN THE WAY OF CLOUD COVER EXPECTED TUESDAY NIGHT AND
WEDNESDAY AS CLOSED UPPER LOW WILL BE WELL TO THE EAST. A WARMING
TREND WILL COMMENCE WEDNESDAY WITH THE RETURN OF LIGHT
SOUTHEASTERLY WINDS.

THE EXTENDED CONTINUES TO LOOK HOT AND DRY AS UPPER RIDGE REMAINS IN
CONTROL. ANOTHER COLD FRONT MAY APPROACH THE AREA BY LATE SATURDAY
BUT AGAIN APPEARS TO BE MOISTURE STARVED. A BIT COOLER WEATHER MAY BE
IN STORE BY SUNDAY IF THIS FRONT DOES INDEED MAKE IT THIS FAR.

STAYED FAIRLY CLOSE TO GUIDANCE TEMPERATURES EXCEPT WENT COOLER FOR
MINIMUMS TUESDAY NIGHT WITH CLEAR SKIES...DRY AIR AND LIGHT WINDS.

FCSTID = 5
TUL   65  93  62  95 /  20   0   0   0
FSM   68  95  64  96 /  30  10   0   0
MLC   68  95  62  97 /  30  10   0   0
BVO   62  92  60  94 /  20   0   0   0
FYV   62  88  55  90 /  30   0   0   0
BYV   62  88  55  90 /  30   0   0   0
MIO   62  90  58  92 /  20   0   0   0
MKO   66  94  62  96 /  30   0   0   0
F10   66  94  62  96 /  30   0   0   0
HHW   70  98  65  98 /  20  20  10   0

.TUL...
AR...NONE.
OK...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: 9 ON A SCALE OF 0 TO 10

In the hours before

Local storm report, Aug 23, 6:08 PM CDT, 1 hour 40 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
608 PM CDT MON AUG 23 1999

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

0600 PM    COWETA                    OK    80 MPH TSTM GUST
08/23/99   WAGONER                         COWETA PD REPORTS
                                           NUMEROUS TREES AND
                                           POWER LINES DOWN IN
                                           COWETA...SPOTTER
                                           ESTIMATED WINDS TO 80
                                           MPH.

Local storm report, Aug 23, 6:08 PM CDT, 1 hour 40 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
608 PM CDT MON AUG 23 1999

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

0600 PM    COWETA                    OK    80 MPH TSTM GUST
08/23/99   WAGONER                         COWETA PD REPORTS
                                           NUMEROUS TREES AND
                                           POWER LINES DOWN IN
                                           COWETA...SPOTTER
                                           ESTIMATED WINDS TO 80
                                           MPH.

Local storm report, Aug 23, 7:27 PM CDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
727 PM CDT MON AUG 23 1999

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

0600 PM    COWETA                    OK    WIND DAMAGE
08/23/99   WAGONER                         1/4 OF ROOF BLOWN OF A
                                           HOUSE

0600 PM    COWETA                    OK    .88 INCH HAIL
08/23/99   WAGONER

0648 PM    7 NE NATURA               OK    70 MPH TSTM GUST
08/23/99   OKMULGEE

0648 PM    NATURA                    OK    .75 INCH HAIL
08/23/99   OKMULGEE

0651 PM    5 SW HASKELL              OK    70 MPH TSTM GUST
08/23/99   MUSKOGEE

0651 PM    HASKELL                   OK    .75 INCH HAIL
08/23/99   MUSKOGEE

0653 PM    7 E NATURA                OK    70 MPH TSTM GUST
08/23/99   OKMULGEE

Local storm report, Aug 23, 7:27 PM CDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
727 PM CDT MON AUG 23 1999

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

0600 PM    COWETA                    OK    WIND DAMAGE
08/23/99   WAGONER                         1/4 OF ROOF BLOWN OF A
                                           HOUSE

0600 PM    COWETA                    OK    .88 INCH HAIL
08/23/99   WAGONER

0648 PM    7 NE NATURA               OK    70 MPH TSTM GUST
08/23/99   OKMULGEE

0648 PM    NATURA                    OK    .75 INCH HAIL
08/23/99   OKMULGEE

0651 PM    5 SW HASKELL              OK    70 MPH TSTM GUST
08/23/99   MUSKOGEE

0651 PM    HASKELL                   OK    .75 INCH HAIL
08/23/99   MUSKOGEE

0653 PM    7 E NATURA                OK    70 MPH TSTM GUST
08/23/99   OKMULGEE

Local storm report, Aug 23, 7:48 PM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
748 PM CDT MON AUG 23 1999

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

0745 PM    1 NW PHAROAH              OK    .88 INCH HAIL
08/23/99   OKFUSKEE

0745 PM    PHAROAH                   OK    60 MPH TSTM GUST
08/23/99   OKFUSKEE

Local storm report, Aug 23, 7:48 PM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
748 PM CDT MON AUG 23 1999

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

0745 PM    1 NW PHAROAH              OK    .88 INCH HAIL
08/23/99   OKFUSKEE

0745 PM    PHAROAH                   OK    60 MPH TSTM GUST
08/23/99   OKFUSKEE

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 23, 7:36 PM CDT	Severe Thunderstorm Warning	TSA	Okfuskee	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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.