Flood in Oklahoma, May 24 to 29, 2002

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OKLAHOMA
950 PM CDT FRI MAY 24 2002

CURRENT TRENDS WARRANT SOME SIGNIFICANT CHANGES TO THE FORECAST THIS
EVENING.

THUNDERSTORM COMPLEX HAS RAPIDLY WEAKENED OVER THE PAST TWO HOURS
WITH THE STRONGEST STORMS NOW NEAR THE KANSAS BORDER IN NORTHERN
OSAGE COUNTY WHERE STORMS HAVE EXHIBITED SOME ROTATION RECENTLY.
LINE OF STORMS APPROACHING SOUTHEAST OKLAHOMA WILL ALSO LIKELY
CONTINUE TO WEAKEN WITH TIME AS THEY MOVE INTO A MORE STABLE AIRMASS.
ALTHOUGH SOME VERY HEAVY RAIN WILL REMAIN POSSIBLE FOR ANOTHER HOUR
OR SO WITHIN 5-10 MILES OF THE KANSAS STATE LINE IN OSAGE
COUNTY...WE WILL GO AHEAD AND CANCEL THE FLASH FLOOD WATCH AS MUCH
OF THE REST OF THE WATCH AREA WILL RECEIVE LITTLE RAIN OVERNIGHT AND
AMOUNTS LAST NIGHT WERE NOT EXCESSIVE EITHER. WILL LOWER POPS IN
MOST AREAS AS WELL OVERNIGHT.

UNSEASONABLY STRONG COLD FRONT HAS BEEN STATIONARY MUCH OF THE
AFTERNOON AND EVENING BUT IS NOW ON THE MOVE AND WILL BISECT THE
FORECAST AREA BY MORNING. VERY CHILLY AREA NORTH OF THE FRONT WILL
PENETRATE NORTHEAST OKLAHOMA AND WILL LOWER MINIMUM TEMPERATURES BY
ABOUT 10 DEGREES IN THIS AREA TONIGHT. WILL ALSO MAKE THE WIND
DIRECTION NORTH BEHIND THE FRONT INSTEAD OF NORTHEAST.

WILL MAKE A FEW CHANGES TO SATURDAY AS WELL. WILL LOWER POPS IN MANY
AREAS AND WILL ALSO ADJUST SKY CONDITION AS QUITE A BIT OF SUN WILL
BE SEEN IN THE AFTERNOON...ESPECIALLY IN NORTHEAST OKLAHOMA. THE
LATE MAY SUN WILL QUICKLY MODIFY THE AIRMASS SO THE GOING FORECAST
MAXIMUMS MAY BE ALL RIGHT...THESE ARE STILL SEVERAL DEGREES BELOW
NORMAL.

NEED TO DO QUITE A BIT OF GRID EDITING SO ZONES WILL BE DELAYED AND
MAY HOLD THEM UNTIL THE WATCH EITHER EXPIRES OR IS CANCELLED.

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

PLATE

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

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
630 PM CDT FRI MAY 24 2002

...SEVERE THUNDERSTORMS LIKELY ACROSS NORTHEASTERN OKLAHOMA THIS
   EVENING AND OVERNIGHT...

...A CHANCE OF SEVERE THUNDERSTORMS ACROSS SOUTHEASTERN OKLAHOMA AND
   NORTHWEST ARKANSAS THIS OVERNIGHT...

...A FLASH FLOOD WATCH THROUGH TONIGHT FOR PORTIONS OF FAR NORTHEAST
   OKLAHOMA...

STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP ALONG AN APPROACHING
COLD FRONT THIS EVENING ACROSS FAR NORTHEAST OKLAHOMA.  ADDITIONAL
SEVERE STORMS HAVE FORMED OVER WESTERN OKLAHOMA AND WILL CONTINUE
MOVING TOWARD EASTERN OKLAHOMA THROUGH THE EVENING.  THE STORMS WILL
MERGE INTO A LARGE COMPLEX AND CONTINUE EASTWARD OVERNIGHT.  STRONG
WINDS AND LARGE HAIL WILL BE THE PRIMARY THREAT FROM THESE STORMS.

.SPOTTER ACTIVATION...
SPOTTER ACTIVATION WILL BE REQUIRED THIS EVENING OVER NORTHEAST
OKLAHOMA...AND LATE TONIGHT OVER SOUTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS.

.DISCUSSION...
A LINE OF SEVERE STORMS HAS FORMED ALONG THE DRYLINE OVER WESTERN
OKLAHOMA...WHILE ADDITIONAL STORMS ARE FORMING IN PROXIMITY TO THE
COLD FRONT ACROSS SOUTHERN KANSAS.  AS AN UPPER LEVEL STORM SYSTEM
LIFTS INTO THE SOUTHERN PLAINS...WIND SHEAR WILL INCREASE ENHANCING
THE POTENTIAL FOR STORM ORGANIZATION.  SUPERCELLS WILL BE POSSIBLE
DURING THE EARLY STAGES OF THIS SEVERE WEATHER EVENT...WITH A
GRADUAL TRANSITION TO A LINEAR MCS AS THE COLD FRONT PUSHES
SOUTHWARD AND SYNOPTIC SCALE LIFT INCREASES ACROSS THE AREA.

THE FLASH FLOOD THREAT REMAINS HIGHEST ACROSS FAR NORTHEAST
OKLAHOMA.  CONCENTRATED THUNDERSTORM DEVELOPMENT ALONG THE
APPROACHING COLD FRONT COUPLED WITH SATURATED SOILS WILL ENHANCE THE
FLASH FLOOD THREAT ACROSS THIS AREA.

THREAT TABLE
VALID THROUGH 1200 UTC SATURDAY

AREA 1...NORTHWEST OF A MCALESTER OKLAHOMA TO MIAMI OKLAHOMA LINE
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...80
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...40

AREA 2...SOUTHEAST OF A MCALESTER OKLAHOMA TO MIAMI OKLAHOMA LINE
THUNDERSTORM PROBABILITY...80
SEVERE PROBABILITY IF STORMS OCCUR...50
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...20

AREA 3...SOUTHEAST OF A FAYETTEVILLE ARKANSAS TO POTEAU OKLAHOMA LINE
THUNDERSTORM PROBABILITY...60
SEVERE PROBABILITY IF STORMS OCCUR...20
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.

.OTHER HAZARDS...
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE ACROSS NORTHEAST OKLAHOMA
THROUGH TONIGHT AND A FLASH FLOOD WATCH HAS BEEN ISSUED.  PLEASE
REFER TO THE FLASH FLOOD WATCH /OKCFFATUL/ FOR ADDITIONAL DETAILS.

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