Severe Thunderstorm Warning 240, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
1000 AM CDT FRI MAY 26 2000

WILL UPDATE THE FORECAST SHORTLY TO CANCEL THE SEVERE THUNDERSTORM
WATCH. STORMS HAVE BEEN WEAKENING AS THEY CONTINUE MOVING ACROSS THE
AREA AND CURRENT MOVEMENT SUGGESTS THAT THE BACK EDGE OF THE RAIN SHOULD
CLEAR THE FORECAST AREA BY EARLY AFTERNOON. SUBSIDENCE IN THE WAKE OF
THE CONVECTION WAS RESULTING IN RAPID CLEARING FROM THE WEST SO SHOULD
STILL SEE TEMPERATURES REACH NEAR THE FORECAST LEVELS. WILL CUT WAY
BACK ON POPS FOR THE AFTERNOON BEHIND THE CURRENT ACTIVITY AND WILL
DECIDE IN THE NEXT FEW MINUTES WHETHER TO DROP THEM ALTOGETHER.

NEXT ROUND EXPECTED TONIGHT AND LOOKS MUCH MORE ACTIVE. BEST INITIAL
GUESS IS FOR STORMS TO INITIATE IN THE WICHITA FALLS AREA LATE THIS
AFTERNOON AND MOVE EAST NORTHEAST ACROSS MAINLY SOUTHEAST OKLAHOMA AND
WEST CENTRAL ARKANSAS OVERNIGHT. EXPECTED INSTABILITY AND PROGGED WIND
PROFILES ARE VERY SUPPORTIVE OF SEVERE STORMS INCLUDING SUPERCELLS.
WILL JUST NUDGE POPS UP SLIGHTLY FOR NOW DOWN SOUTH TONIGHT AND WILL
CONTINUE TO EXAMINE THE SITUATION FURTHER THIS AFTERNOON.

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

PLATE

ARZ001-002-010-011-019-020-029-OKZ049-053>076-271200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
605 AM CDT FRI MAY 26 2000

...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THIS MORNING ACROSS
SOUTHEAST OKLAHOMA...

...ISOLATED SEVERE THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON AND
TONIGHT ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS...

.SYNOPSIS...
A LARGE COMPLEX OF THUNDERSTORMS STRETCHING FROM WESTERN MISSOURI
INTO SOUTHWEST OKLAHOMA EARLY THIS MORNING WILL MOVE EAST ACROSS THE
AREA BEFORE WEAKENING BY LATE MORNING.  A WARM FRONT OVER NORTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS WILL LIFT NORTH TODAY...AND SHOULD
BE LOCATED OVER NEBRASKA AND MISSOURI BY LATE AFTERNOON.

.PRIMARY HAZARD...
THUNDERSTORMS STRETCHING FROM SOUTHWEST OKLAHOMA INTO NORTHEAST
OKLAHOMA WILL SLOWLY WEAKEN AS THEY MOVE EAST ACROSS THE THE
REMAINDER OF OKLAHOMA AND NORTHWEST ARKANSAS THIS MORNING.  THE
STRONGEST STORMS ARE EXPECTED TO MOVE INTO PARTS OF SOUTHEAST
OKLAHOMA AFTER 8 AM...AND MAY BE CAPABLE OF PRODUCING DAMAGING WINDS
AND LARGE HAIL.  THESE STORMS SHOULD WEAKEN AFTER 10 OR 11 AM.

THUNDERSTORMS MAY REDEVELOP BY LATE AFTERNOON OVER NORTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS.  ADDITIONAL THUNDERSTORMS ARE
EXPECTED TO DEVELOP OVER EASTERN KANSAS THIS EVENING...AND MAY MOVE
INTO FAR NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS AROUND MIDNIGHT.
THE MAIN SEVERE WEATHER THREAT FROM THESE STORMS WOULD BE LARGE HAIL
AND DAMAGING WINDS.

.DISCUSSION...
A THUNDERSTORM COMPLEX EXHIBITING BOW-ECHO CHARACTERISTICS IS
EXPECTED TO MOVE INTO PARTS OF SOUTHEAST OKLAHOMA AFTER 8 AM.  THE
ATMOSPHERE AHEAD OF THE BOW-ECHO REMAINS VERY UNSTABLE THIS
MORNING...SO THUNDERSTORMS ARE EXPECTED TO REMAIN ABOVE SEVERE
LIMITS AS THEY ENTER SOUTHEAST OKLAHOMA.  THE PRIMARY SEVERE WEATHER
THREAT WILL BE DAMAGING STRAIGHT-LINE WINDS...PRIMARLY SOUTH OF A
OKEMAH TO MUSKOGEE TO TAHLEQUAH LINE.  THUNDERSTORMS SHOULD WEAKEN
ACROSS SOUTHEAST OKLAHOMA BY 10 TO 11 AM.

AN OUTFLOW BOUNDARY FROM THIS MORNINGS CONVECTION SHOULD LIE ACROSS
NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS BY THIS AFTERNOON.  WHILE
DEBRIS CLOUDS WILL HAMPER WARMING SOME...THE ATMOSPHERE IS EXPECTED
TO BECOME VERY UNSTABLE WITH CAPES AROUND 2000-4000 J/KG BY LATE
AFTERNOON.  A CAP OF WARM AIR ALOFT WILL BUILD INTO MUCH OF THE AREA
TODAY...SO IT IS STILL UNCERTAIN WHETHER THUNDERSTORM DEVELOPMENT
WILL OCCUR.  THE BEST CHANCES WOULD BE OVER NORTHEAST OKLAHOMA AND
NORTHWEST ARKANSAS AFTER 4 PM...WHERE THE OUTFLOW BOUNDARY WILL BE
POSITIONED AND THE CAP IS THE WEAKEST.  GIVEN THE DEGREE OF
INSTABILITY...ANY THUNDERSTORMS THAT FORM WOULD QUICKLY BECOME
SEVERE WITH LARGE HAIL AND GUSTY WINDS POSSIBLE.

ADDITIONAL THUNDERSTORMS MAY FORM THIS EVENING OVER EASTERN KANSAS
IN REPSONSE TO A 50 KNOT SOUTHWESTERLY LOW-LEVEL JET AND A 80 KNOT
UPPER-LEVEL JET.  IF THESE STORMS FORM...THEY WOULD TRACK
EAST-SOUTHEAST...POSSIBLY AFFECTING PARTS OF NORTHEAST OKLAHOMA AND
NORTHWEST ARKANSAS AFTER MIDNIGHT.  LARGE HAIL AND DAMAGING WINDS WILL
BE POSSIBLE WITH THESE STORMS.

.SPOTTER ACTIVATION...
SPOTTER ACTIVATION WILL BE REQUIRED OVER SOUTHEAST OKLAHOMA THIS
MORNING.  SPOTTER ACTIVIATION OVER NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS MAY BE NECESSARY BY LATE AFTERNOON.

AN UPDATED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AROUND 1 PM.

OKZ049-053-065-066-068>076-261600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
1020 AM CDT FRI MAY 26 2000

...THE SEVERE THUNDERSTORM WATCH HAS BEEN CANCELLED FOR THE
FOLLOWING COUNTIES IN:

EASTERN OKLAHOMA...
         ADAIR               CHOCTAW             HASKELL
         LATIMER             LE FLORE            MCINTOSH
         MUSKOGEE            CHEROKEE            OKFUSKEE
         OKMULGEE            PITTSBURG           PUSHMATAHA
         SEQUOYAH