Hail and Damaging Winds in Oklahoma, May 27 to 28, 2001

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
1108 AM CDT SUN MAY 27 2001

LINGERING CONVECTION NEAR THE FAR SOUTHEASTERN TIP OF OK FROM
OVERNIGHT STORMS THAT SLIPPED BY TO THE SOUTH.  ASSOCIATED BOUNDARY
LIES TO THE SOUTH...WHILE LATEST SURFACE ANALYSIS SHOWS ANOTHER WEAK
SURFACE BOUNDARY TO THE NORTH ACROSS KANSAS.

SATL SHOWING A LITTLE ENHANCEMENT WITH THE CLOUDS NORTHWEST OF THE
AREA ACROSS KS/NE AND WILL WATCH FOR ADDITIONAL STORMS TO FIRE TO
THE NORTHWEST OF THE AREA THROUGH THE AFTERNOON.

CURRENT FORECAST LOOKS FINE FOR THIS AFTERNOON...WILL ONLY NEED TO
FINE TUNE THE WORDING A LITTLE.

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

ARZ001-002-010-011-019-020-029-OKZ049-053>076-281100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
100 PM CDT SUN MAY 27 2001

...SCATTERED SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON AND
   EVENING ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...
...A FEW SEVERE THUNDERSTORMS ARE EXPECTED OVERNIGHT...MAINLY
   IN SOUTHEAST OKLAHOMA...

A STATIONARY FRONT WAS LOCATED ACROSS SOUTHEAST KANSAS EXTENDING
SOUTHEAST INTO NORTHWEST ARKANSAS EARLY THIS AFTERNOON. SCATTERED
STRONG TO SEVERE THUNDERSTORMS HAVE ALREADY DEVELOPED ALONG THIS
BOUNDARY IN SOUTHEAST KANSAS. THE THUNDERSTORM ACTIVITY IS EXPECTED
TO INCREASE IN COVERAGE AND INTENSITY...MOVING SOUTHEAST INTO EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS THIS AFTERNOON AND EARLY EVENING.
SOME OF THESE STORMS WILL LIKELY BE SEVERE WITH LARGE HAIL AND
DAMAGING WINDS.

A SECONDARY COMPLEX OF SEVERE THUNDERSTORMS IS FORECAST TO DEVELOP
OVER NORTHWEST OKLAHOMA THIS EVENING...POSSIBLY MOVING INTO
SOUTHEAST OKLAHOMA AFTER MIDNIGHT. THESE STORMS COULD ALSO PRODUCE
LARGE HAIL...DAMAGING WINDS AND VERY HEAVY RAINFALL.

.SPOTTER ACTIVATION...
ACTIVATION OF STORM SPOTTER GROUPS WILL LIKELY BE REQUIRED THIS
AFTERNOON ACROSS PORTIONS OF EASTERN OKLAHOMA AND NORTHWEST
ARKANSAS.

.DISCUSSION...
A STATIONARY BOUNDARY WAS LOCATED OVER SOUTHEAST KANSAS EARLY THIS
AFTERNOON.  STRONG THUNDERSTORMS HAVE ALREADY DEVELOPED ALONG THE
BOUNDARY WHERE WEAK LOW LEVEL MOISTURE CONVERGENCE IS OCCURRING.
SOUTH OF THE BOUNDARY...THE AIRMASS HAS BECOME VERY UNSTABLE WITH
CAPE VALUES BETWEEN 2500-3500 J/KG...AND LIFTED INDICES BETWEEN -7
AND -9 C. CONVECTION WILL LIKELY BECOME BETTER ORGANIZED...AS STORMS
MOVE SOUTHEAST INTO A MORE UNSTABLE AIRMASS. GIVEN THE INSTABILITY
IN PLACE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY WITH THESE
STORMS.

AN ADDITIONAL AREA OF SEVERE THUNDERSTORMS ARE FORECAST TO DEVELOP
ACROSS PORTIONS OF NORTHWEST OKLAHOMA BY EARLY EVENING. THESE STORMS
WILL INITIALLY BE SUPERCELL THUNDERSTORMS...BUT ARE EXPECTED TO
ORGANIZE INTO A CONVECTIVE COMPLEX THAT WILL MOVE RAPIDLY
SOUTHEAST...MAINLY INTO SOUTHEAST OKLAHOMA DURING THE OVERNIGHT
HOURS. THE PRIMARY THREAT FROM THESE THUNDERSTORMS WILL BE
STRONG DAMAGING WINDS.  IF OUTFLOW BOUNDARIES FROM THE CONVECTION
THIS AFTERNOON PUSHES THROUGH SOUTHEAST OKLAHOMA THIS EVENING...THE
SECONDARY THUNDERSTORM COMPLEX MAY TRACK FURTHER WEST...LIMITING THE
SEVERE WEATHER THREAT IN SOUTHEAST OKLAHOMA OVERNIGHT.

THREAT TABLE
VALID THROUGH 1200 UTC MONDAY

THREAT AREA 1...EASTERN OKLAHOMA/NORTHWEST ARKANSAS
THUNDERSTORM PROBABILITY...60
SEVERE PROBABILITY IF STORMS OCCUR...70
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...20

THREAT AREA 2...SOUTHWEST OF A LINE FROM PAWNEE TO TALIHINA
THUNDERSTORM PROBABILITY...80
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...
HTTP://WWW.SRH.NOAA.GOV/TULSA

.OTHER HAZARDS...
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE DURING THE OVERNIGHT HOURS
WITH THE COMPLEX OF THUNDERSTORMS EXPECTED TO MOVE ACRZOSS SOUTHEAST
OKLAHOMA. ISOLATED FLOODING WILL BE POSSIBLE...BUT MAINLY LIMITED TO
LOW LYING AND POOR DRAINAGE AREAS. WIDESPREAD FLASH FLOODING IS NOT
EXPECTED.