Severe Thunderstorm Warning 267, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OKLAHOMA
930 PM SAT AUG 24 2002

TRICKY FIRST PERIOD AS FAR AS POPS GO. SURFACE BOUNDARY THIS
EVENING EXTENDS FROM WEST CENTRAL TO SE OK. LOOKS LIKE THE MAIN
PLAYER FOR SRN ZONES TONIGHT MAY BE STORMS CURRENTLY ACROSS THE TX
PANHANDLE/NW OK THAT HAD DEVELOPED IN THE VICINITY OF THE BOUNDARY
AND ARE PUSHING TO THE EAST SOUTHEAST. OTHER STORMS...MORE ELEVATED
IN NATURE HAVE DEVELOPED ACROSS KANSAS AND MISSOURI THOUGH CURRENTLY
REMAIN NORTH OF THE FA. WILL LEAVE POPS AS THEY ARE GIVEN CURRENT
RADAR TRENDS AND PROXIMITY OF BOUNDARY. CURRENTLY ADVERTISED LOWS
LOOK REASONABLE. WILL NOT ISSUE AN UPDATE AT THIS TIME...THOUGH WILL
MONITOR TEMPERATURE AND CONVECTIVE TRENDS FOR POSSIBLE UPDATE
TOWARDS MIDNIGHT.

FORECAST ID= 23

.TSA...
AR...NONE.
OK...NONE.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
655 PM CDT SAT AUG 24 2002

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

0600 PM    PICHER                    OK   WIND DAMAGE
08/23/02   OTTAWA                         TREES BLOWN DOWN. REPORTED
                                          BY LAW ENFORCEMENT

0730 PM    PICHER                    OK   FLOOD
08/23/02   OTTAWA                         WATER OVER ROAD ON HIGHWAY
                                          69. REPORTED BY LAW
                                          ENFORCEMENT

0757 PM    FOYIL                     OK   65 MPH TSTM WIND GUST
08/23/02   ROGERS                         REPORTED BY LAW
                                          ENFORCEMENT

0810 PM    CLAREMORE                 OK   65 MPH TSTM WIND GUST
08/23/02   ROGERS                         REPORTED BY LAW
                                          ENFORCEMENT

0910 PM    BARTLESVILLE              OK   71 MPH TSTM WIND GUST
08/23/02   OSAGE                          RECORDED BY BVO ASOS
                                          AT FRANK PHILLIPS AIRPORT

1140 PM    CLEVELAND                 OK   WIND DAMAGE
08/23/02   PAWNEE                         TREES DAMAGED BY WINDS
                                          ESTIMATED UP TO 60 MPH.
                                          REPORTED BY LAW
                                          ENFORCEMENT

ARZ001-002-010-011-019-020-029-OKZ049-053>076-251200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TULSA OK
845 PM CDT SAT AUG 24 2002

...CHANCE OF SEVERE THUNDERSTORMS TONIGHT...

A STATIONARY SURFACE BOUNDARY EXTENDED FROM NEAR OKLAHOMA CITY TO
JUST NORTH OF MCALESTER TO SOUTH OF FORT SMITH. SCATTERED
THUNDERSTORMS WERE BEGINNING TO DEVELOP NEAR THE BOUNDARY ACROSS
WESTERN AND CENTRAL OKLAHOMA THIS EVENING. SCATTERED TO NUMEROUS
THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE BOUNDARY ACROSS
EASTERN OKLAHOMA LATER THIS EVENING AS LIFTING INCREASES AHEAD OF AN
UPPER LEVEL SYSTEM.

A FEW OF THE THUNDERSTORMS...ESPECIALLY IN AREAS SOUTH OF A LINE
FROM TULSA TO FORT SMITH...COULD BECOME SEVERE TONIGHT AND PRODUCE
LARGE HAIL AND DAMAGING WINDS. THE AIRMASS IS SLIGHTLY MORE STABLE
IN AREAS NORTH OF A TULSA TO FORT SMITH LINE...SO LESS INTENSE
THUNDERSTORMS ARE FORECAST IN THESE AREAS.

.SPOTTER ACTIVATION...
SPOTTER ACTIVATION MAY BE NEEDED BY MIDNIGHT ACROSS PARTS OF
EASTERN OKLAHOMA AND WESTERN ARKANSAS.

.DISCUSSION...
CONVECTIVE DEVELOPMENT IS EXPECTED BY MIDNIGHT AS WARM ADVECTION
LIFT INCREASES ALONG AND NORTH OF THE SURFACE BOUNDARY. ELEVATED
INSTABILITIES OF 2500 J/KG AND MID LEVEL NORTHWESTERLY WINDS
INCREASING TO OVER 30 KNOTS SUPPORT THE POTENTIAL FOR SEVERE
THUNDERSTORMS. MARGINALLY SEVERE HAIL WILL BE POSSIBLE WITH SOME OF
THE THUNDERSTORMS...BUT THE PRIMARY SEVERE WEATHER THREAT WILL BE
DAMAGING STRAIGHT LINE WINDS.

STRONG DIVERGENCE IN THE LEFT FRONT QUADRANT OF AN 80 KNOT UPPER JET
WILL MOVE ACROSS EXTREME NORTHERN OKLAHOMA AND THE NORTHWEST CORNER
OF ARKANSAS TONIGHT. THIS UPPER SUPPORT IS NORMALLY FAVORABLE FOR
SEVERE THUNDERSTORM DEVELOPMENT...BUT INSTABILITY IS LOWER IN THIS
AREA SINCE EARLIER CONVECTION HAD A STABILIZING EFFECT. ISOLATED
SEVERE THUNDERSTORMS WILL STILL BE POSSIBLE...BUT THE MORE ORGANIZED
ACTIVITY IS EXPECTED TO REMAIN FURTHER SOUTH NEAR THE SURFACE
BOUNDARY.

RISK TABLE
VALID THROUGH 1200 UTC SUNDAY

AREA 1...ALONG AND SOUTH OF A LINE FROM TULSA TO FORT SMITH
THUNDERSTORM PROBABILITY...90
SEVERE PROBABILITY IF STORMS OCCUR...50
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...30

AREA 2...NORTH OF A LINE FROM TULSA TO FORT SMITH
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...20
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...10

RISK AREAS DEFINE THE GREATEST RISK. PROBABILITIES ARE IN PERCENT.
SIGNIFICANT SEVERE IS DEFINED AS F1 OR GREATER WIND/TORNADO DAMAGE
AND/OR GOLFBALL SIZE HAIL OR LARGER.

.OTHER HAZARDS...
LOCALLY HEAVY RAINFALL IS POSSIBLE TONIGHT AND EARLY SUNDAY MORNING
AS SEVERAL ROUNDS OF THUNDERSTORMS AFFECT THE AREA.

RELATED GRAPHICAL INFORMATION CAN BE FOUND AT:
WWW.SRH.NOAA.GOV/TULSA