Severe Thunderstorm Warning 119, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
400 PM CDT FRI MAY 11 2001

NUMEROUS OUTFLOW BOUNDARIES ACROSS THE FORECAST AREA THIS AFTERNOON.
THUNDERSTORMS DEVELOPING IN UNCAPPED AIRMASS WITH WEAK WINDS ALOFT
LEADING TO CELL MERGERS PRODUCING LOCALLY VERY HEAVY RAINFALL RATES
AND ISOLATED SEVERE WEATHER. LOOKS LIKE THIS SCENARIO WILL CONTINUE
WELL INTO THE EVENING HOURS WITH NET PROPAGATION TO THE SOUTH AND
SOUTHWEST. SEVERE THUNDERSTORM WATCH IS BEING ISSUED FOR THE
SOUTHWEST PART OF THE FORECAST AREA AT THIS TIME.

MAIN SYNOPTIC SCALE FRONT HAS BECOME LOST IN THE MYRIAD OF OUTFLOWS
BUT THE DRIER AIR IS STILL BACK NEAR AN EMPORIA TO WICHITA LINE. NOT
TOO MUCH CHANCE FOR REDEVELOPMENT ALONG THIS BOUNDARY OVERNIGHT BUT
WILL LEAVE AT LEAST SLIGHT CHANCE POPS IN EVERYWHERE FOR AFTER 00Z.
WILL NEED TO ADD A REST OF THIS AFTERNOON PERIOD TO SOME OF THE
NORTHEAST OKLAHOMA ZONES DUE TO ONGOING CONVECTION.

SKIES SHOULD CLEAR LATER TONIGHT IN NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS BUT FRONT WILL HANG UP IN THE HILLS OF SOUTHEAST OKLAHOMA
AND WEST CENTRAL ARKANSAS. WILL KEEP POPS GOING SATURDAY IN THAT
AREA DUE TO THE POSSIBILITY OF LINGERING ACTIVITY BEYOND 12Z AND
ALSO THE POTENTIAL FOR REDEVELOPMENT SATURDAY AFTERNOON WHERE
RESIDUAL MOISTURE WILL LINGER.

SATURDAY NIGHT AND SUNDAY LOOK DRY WITH A WARMING TREND BEGINNING
SUNDAY AND CONTINUING INTO NEXT WEEK AS UPPER RIDGE BUILDS OVER THE
AREA. THE HEAT WILL BE ON IN THE MONDAY THROUGH WEDNESDAY TIMEFRAME
WITH AT LEAST LOWER 90S LIKELY EVERYWHERE EXCEPT IN THE OZARKS.
UNCERTAINTIES INCREASE BEYOND MIDWEEK BUT IT APPEARS THAT A SURFACE
FRONTAL BOUNDARY MAY MOVE DOWN NEAR OR INTO THE AREA AND STALL. THUS
WILL INCLUDE LOW POPS BEGINNING WEDNESDAY NIGHT (WILL BE WORDED AS
LATE WEDNESDAY IN ICWF) AND CONTINUING THROUGH FRIDAY. SLIGHTLY
COOLER WEATHER MAY ALSO BE SEEN LATE NEXT WEEK...ESPECIALLY IN THE
NORTHERN PART OF THE AREA.

STAYED CLOSE TO GUIDANCE TEMPERATURES THROUGH SATURDAY NIGHT BUT
WENT WARMER THAN GUIDANCE ON SUNDAY.

FCSTID = 5
TUL   58  82  59  87 /  30   0   0   0
FSM   60  83  54  87 /  50  20  10   0
MLC   61  83  57  86 /  70  20  10   0
BVO   55  82  55  88 /  20   0   0   0
FYV   55  79  50  82 /  30   0   0   0
BYV   55  79  50  82 /  20   0   0   0
MIO   55  80  53  85 /  20   0   0   0
MKO   60  83  56  87 /  40  10   0   0
F10   60  82  58  87 /  50  10   0   0
HHW   62  83  56  86 /  70  30  10   0

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

PLATE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
1206 PM CDT FRI MAY 11 2001

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

1120 AM    CENTERTON                 AR    .75 INCH HAIL
05/11/01   BENTON                          REPORTED BY SHERIFFS
                                           DEPT.

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 FRI MAY 11 2001

...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE OVER PORTIONS OF
EASTERN OKLAHOMA AND WEST CENTRAL ARKANSAS THIS AFTERNOON...

EARLY THIS AFTERNOON...ONE AREA OF THUNDERSTORMS WAS PUSHING SLOWLY
SOUTHWARD ACROSS NORTHWEST ARKANSAS AND EAST CENTRAL OKLAHOMA...
WHILE A SECOND AREA OF THUNDERSTORMS WAS MOVING SOUTHWARD INTO NORTH
CENTRAL OKLAHOMA.  AT THE SURFACE...A COLD FRONT EXTENDED FROM
NORTHWEST OKLAHOMA INTO WESTERN MISSOURI...WHILE AN OUTFLOW BOUNDARY
EXTENDED EASTWARD ACROSS NORTH CENTRAL AND NORTHEAST OKLAHOMA AND
THEN SOUTHEAST AHEAD OF THE STORMS IN NORTHWEST ARKANSAS.

BOTH AREAS OF THUNDERSTORMS ARE EXPECTED TO CONTINUE MOVING SOUTH
ACROSS EASTERN OKLAHOMA AND WEST CENTRAL ARKANSAS THROUGH THE
AFTERNOON.  WITH SOME AFTERNOON HEATING...THE ATMOSPHERE AHEAD OF
THE STORMS WILL BECOME MORE UNSTABLE AND A FEW OF THE STORMS MAY
BRIEFLY INTENSIFY TO SEVERE LEVELS.  THE STRONGEST STORMS WILL
PRODUCE HAIL UP TO ONE INCH IN DIAMETER AND VERY ISOLATED OUTFLOW
WINDS UP TO 60 MPH.  A POTENTIALLY MORE SIGNIFICANT THREAT COULD BE
LOCALLY HEAVY RAINFALL...AS BETWEEN 1 AND 2 INCHES OF RAIN COULD
FALL THIS AFTERNOON IN A FEW ISOLATED AREAS.

THE SEVERE WEATHER THREAT WILL COME TO AN END FROM NORTH TO SOUTH
ACROSS THE AREA AND SHOULD BE ENTIRELY OUT OF THE AREA THIS EVENING.

.SPOTTER ACTIVATION...
STORM SPOTTER GROUPS AND EMERGENCY MANAGERS SHOULD MONITOR THE
LATEST FORECASTS AND UPDATES...AND BE PREPARED FOR POSSIBLE
ACTIVATION THIS AFTERNOON.

.DISCUSSION...
THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP IN THE VICINITY OF
THE OUTFLOW BOUNDARY...LIKELY FORMING A LARGE BAND OF SHOWERS AND
THUNDERSTORMS ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS BY 3 PM.
DESPITE CAPE VALUES OVER 2000 J/KG IN THE AREA AHEAD OF THE
BOUNDARY...A VERY WEAK WIND FIELD ALOFT AND THE LARGE NUMBER OF
STORMS EXPECTED WILL LIKELY PREVENT THE DEVELOPMENT OF ANY ORGANIZED
SEVERE STORMS THIS AFTERNOON.  HOWEVER...A FEW EMBEDDED
THUNDERSTORMS MAY BRIEFLY PULSE UP TO SEVERE LEVELS...BUT ANY SEVERE
WEATHER EVENT WILL BE VERY SHORT-LIVED AND ISOLATED.

GIVEN THE RELATIVELY SLOW MOTION OF THE AREA OF STORMS...SOME AREAS
MAY RECEIVE UP TO 2 INCHES OF RAINFALL.  ISOLATED RUNOFF PROBLEMS
COULD RESULT.

THREAT TABLE
VALID THROUGH 1200 UTC SATURDAY

THREAT AREA 1...SOUTHWEST OF A PONCA CITY TO TULSA TO FORT SMITH
LINE.
THUNDERSTORM PROBABILITY...90
SEVERE PROBABILITY IF STORMS OCCUR...20
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...2

THREAT 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.

A GRAPHICAL VERSION OF THIS OUTLOOK CAN BE FOUND AT:
WWW.SRH.NOAA.GOV/TULSA

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 FRI MAY 11 2001

...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE OVER PORTIONS OF
EASTERN OKLAHOMA AND WEST CENTRAL ARKANSAS THIS AFTERNOON...

EARLY THIS AFTERNOON...ONE AREA OF THUNDERSTORMS WAS PUSHING SLOWLY
SOUTHWARD ACROSS NORTHWEST ARKANSAS AND EAST CENTRAL OKLAHOMA...
WHILE A SECOND AREA OF THUNDERSTORMS WAS MOVING SOUTHWARD INTO NORTH
CENTRAL OKLAHOMA.  AT THE SURFACE...A COLD FRONT EXTENDED FROM
NORTHWEST OKLAHOMA INTO WESTERN MISSOURI...WHILE AN OUTFLOW BOUNDARY
EXTENDED EASTWARD ACROSS NORTH CENTRAL AND NORTHEAST OKLAHOMA AND
THEN SOUTHEAST AHEAD OF THE STORMS IN NORTHWEST ARKANSAS.

BOTH AREAS OF THUNDERSTORMS ARE EXPECTED TO CONTINUE MOVING SOUTH
ACROSS EASTERN OKLAHOMA AND WEST CENTRAL ARKANSAS THROUGH THE
AFTERNOON.  WITH SOME AFTERNOON HEATING...THE ATMOSPHERE AHEAD OF
THE STORMS WILL BECOME MORE UNSTABLE AND A FEW OF THE STORMS MAY
BRIEFLY INTENSIFY TO SEVERE LEVELS.  THE STRONGEST STORMS WILL
PRODUCE HAIL UP TO ONE INCH IN DIAMETER AND VERY ISOLATED OUTFLOW
WINDS UP TO 60 MPH.  A POTENTIALLY MORE SIGNIFICANT THREAT COULD BE
LOCALLY HEAVY RAINFALL...AS BETWEEN 1 AND 2 INCHES OF RAIN COULD
FALL THIS AFTERNOON IN A FEW ISOLATED AREAS.

THE SEVERE WEATHER THREAT WILL COME TO AN END FROM NORTH TO SOUTH
ACROSS THE AREA AND SHOULD BE ENTIRELY OUT OF THE AREA THIS EVENING.

.SPOTTER ACTIVATION...
STORM SPOTTER GROUPS AND EMERGENCY MANAGERS SHOULD MONITOR THE
LATEST FORECASTS AND UPDATES...AND BE PREPARED FOR POSSIBLE
ACTIVATION THIS AFTERNOON.

.DISCUSSION...
THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP IN THE VICINITY OF
THE OUTFLOW BOUNDARY...LIKELY FORMING A LARGE BAND OF SHOWERS AND
THUNDERSTORMS ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS BY 3 PM.
DESPITE CAPE VALUES OVER 2000 J/KG IN THE AREA AHEAD OF THE
BOUNDARY...A VERY WEAK WIND FIELD ALOFT AND THE LARGE NUMBER OF
STORMS EXPECTED WILL LIKELY PREVENT THE DEVELOPMENT OF ANY ORGANIZED
SEVERE STORMS THIS AFTERNOON.  HOWEVER...A FEW EMBEDDED
THUNDERSTORMS MAY BRIEFLY PULSE UP TO SEVERE LEVELS...BUT ANY SEVERE
WEATHER EVENT WILL BE VERY SHORT-LIVED AND ISOLATED.

GIVEN THE RELATIVELY SLOW MOTION OF THE AREA OF STORMS...SOME AREAS
MAY RECEIVE UP TO 2 INCHES OF RAINFALL.  ISOLATED RUNOFF PROBLEMS
COULD RESULT.

THREAT TABLE
VALID THROUGH 1200 UTC SATURDAY

THREAT AREA 1...SOUTHWEST OF A PONCA CITY TO TULSA TO FORT SMITH
LINE.
THUNDERSTORM PROBABILITY...90
SEVERE PROBABILITY IF STORMS OCCUR...20
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...2

THREAT 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.

A GRAPH
ICAL VERSION OF THIS OUTLOOK CAN BE FOUND AT:
WWW.SRH.NOAA.GOV/TULSA

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
344 PM CDT FRI MAY 11 2001

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

024T5 PM    4 W HULBERT               OK    1 INCH HAIL
05/11/01   CHEROKEE                        REPORTED AT SEQUOYAH
                                           STATE PARK