Hail in Oklahoma, April 29 to 30, 2002

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
935 PM CDT MON APR 29 2002

WARM FRONT HAS REMAINED DRAPED ACROSS RED RIVER VALLEY MOST OF THE
DAY...WITH LARGE SUPERCELLS FORMING IN THE WARM SECTOR OF NORTH
CENTRAL TEXAS THIS EVENING.  FTW HODOGRAPH SUPPORTS SPLITTING STORM
EVOLUTIONS AND THIS HAS BEEN EVIDENT ON AREA RADARS.  MEAN WIND FLOW
IS WESTERLY WITH ONLY THE LEFT SPLIT STORMS HAVING THE GREATEST
CHANCE OF ENTERING THE AREA LATE THIS EVENING.  AS THEY
APPROACH...THEY WILL ENCOUNTER WARM FRONTAL BOUNDARY AND BEGIN TO
WEAKEN AS SURFACE BASED INSTABILITY SOURCE IS LOST.  ABSENCE OF LOW
LEVEL JET DURING THIS TIME FRAME WILL ALSO INHIBIT STORM SURVIVAL.

LOW LEVEL JET WILL BEGIN TO STRENGTHEN OVERNIGHT AND PROVIDE SOURCE
FOR ELEVATED THUNDERSTORMS TO REDEVELOP.  INITIATION AREA IS
SOMEWHAT QUESTIONABLE...HOWEVER AREAS NEAR WARM FRONTAL BOUNDARY
WILL LIKELY EXPERIENCE THE INITIAL STRONGEST THETA-E
ADVECTION...WITH PRECIP DEVELOPING FURTHER NORTHWARD TOWARD SUNRISE
AS NOSE OF LOW LEVEL JET PUSHES NORTHWARD.  BELIEVE FAR NORTHWEST
ARKANSAS WILL BE LEAST LIKELY TO RECEIVE RAINFALL DURING THE
OVERNIGHT PERIOD AND HAVE LOWERED POPS.  WILL KEEP OTHER POPS
SIMILIAR TO GOING FORECAST...WITH MINOR TWEAKS MADE TO FORECAST LOWS.

UPDATE OUT QUICKLY.

FCSTID = 07

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

ARZ001-002-010-011-019-020-029-OKZ049-053>076-301200-

EASTERN OKLAHOMA / NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
720 PM CDT MON APR 29 2002

...A SLIGHT CHANCE OF SEVERE THUNDERSTORMS OVER FAR SOUTHEAST
   OKLAHOMA THIS EVENING...

...A CHANCE OF SEVERE THUNDERSTORMS LATE TONIGHT OVER NORTHEAST
   OKLAHOMA...

A WARM FRONT WAS LOCATED OVER SOUTH-CENTRAL OKLAHOMA EARLY THIS
EVENING. SEVERE THUNDERSTORMS HAVE DEVELOP SOUTH OF THE FRONT OVER
NORTH TEXAS. THESE STORMS MAY MOVE INTO FAR SOUTHEAST OKLAHOMA BY
LATE EVENING AND BE CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING
WINDS.

ADDITIONAL THUNDERSTORMS MAY DEVELOP LATE TONIGHT OVER NORTHEAST
OKLAHOMA...MOVING EAST INTO FAR NORTHWEST ARKANSAS DURING THE
MORNING HOURS. ANY STORMS THAT DEVELOP WOULD LIKELY BE SEVERE WITH
THE THREAT FOR LARGE HAIL.

.SPOTTER ACTIVATION...
SPOTTER ACTIVATION MAY BE REQUIRED LATER THIS EVENING OVER FAR
SOUTHEAST OKLAHOMA AND LATE TONIGHT OVER NORTHEAST OKLAHOMA.

.DISCUSSION...
SEVERE THUNDERSTORMS HAVE DEVELOPED EARLY THIS EVENING OVER NORTH
TEXAS...NEAR INTERSECTION OF THE DRY LINE AND SURFACE TROUGH...WHICH
WAS LOCATED SOUTH OF THE WARM FRONT. SCATTERED SEVERE THUNDERSTORMS
WILL CONTINUE MOVING NORTHEAST ACROSS NORTH TEXAS THIS EVENING.  A
FEW OF THESE STORMS MAY MOVE INTO FAR SOUTHEAST OKLAHOMA BEFORE
WEAKENING AROUND MIDNIGHT.

AS A STRONG LOW LEVEL JET DEVELOPS LATE TONIGHT...ELEVATED SEVERE
THUNDERSTORMS MAY DEVELOP OVER NORTHEAST OKLAHOMA...MOVING EAST INTO
FAR NORTHWEST ARKANSAS DURING THE MORNING HOURS TUESDAY.  STEEP MID
LEVEL LAPSE RATES IN CONJUNCTION WITH LOW WET BULB ZERO HEIGHTS...
SUGGEST A THREAT FOR LARGE HAIL WITH THE STRONGER CELLS.

THREAT TABLE
VALID THROUGH 1200 UTC TUESDAY

AREA 1...PUSHMATAHA AND CHOCTAW COUNTIES LATE THIS EVENING
THUNDERSTORM PROBABILITY...20
SEVERE PROBABILITY IF STORMS OCCUR...50
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...20

AREA 1...NORTHEAST OKLAHOMA LATE TONIGHT
THUNDERSTORM PROBABILITY...50
SEVERE PROBABILITY IF STORMS OCCUR...60
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...10

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.

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