Damaging Winds in Oklahoma, February 19, 2002

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
340 AM CST TUE FEB 19 2002

FORECAST CONCERNS DEAL WITH CHANCE OF SEVERE WEATHER AND POPS
THROUGH THIS EVENING.

00Z SOUNDINGS WERE STRONGLY CAPPED THIS EVENING...WITH ONLY WEAK
ELEVATED SHOWERS ACROSS THE FORECAST AREA.  MAIN CONVECTIVE LINE
INITIALLY DEVELOPED EARLIER THIS EVENING ACROSS WRN/SWRN OK...AHEAD
OF DRYLINE.  THIS ACTIVITY HAS STRENGTHENED AND SHOWN BETTER
ORGANIZATION OVER THE PAST 1-2 HOURS AS IT ENCOUNTERED LOW-LEVEL
JET/ELEVATED INSTABILITY.  00Z AND 06Z MESOETA ARE A LITTLE SLOW IN
PICKING UP THIS CONVECTIVE LINE...BUT OVERALL NOT TOO BAD.

BAND OF ELEVATED SHOWERS/THUNDERSTORMS WILL APPROACH NWRN PARTS OF
FORECAST AREA DURING THE NEXT HOUR...AND MOVE THROUGH MUCH OF THE
AREA BY 17-20Z.  WILL GO WITH HIGH POPS ALL ZONES...WORDED AS MAINLY
IN THE MORNING.  AN ISOLATED HAILER OR TWO WILL BE POSSIBLE.

OF MORE CONCERN...HOWEVER...IS THE POSSIBILITY OF REDEVELOPMENT BY
LATE AFTERNOON/EARLY EVENING AS PAC FRONT/DRYLINE APPROACHES.
INSOLATION WILL BE HINDERED BY LINGERING PRECIPITATION/CLOUD
COVER...ALTHOUGH MESOETA SUGGESTS SURFACE BASED CAPES AROUND
1000-1500 J/KG AND IMPRESSIVE SPEED SHEAR.  ALTHOUGH MODELS DONT
BREAK OUT CONVECTIVE PRECIP LATER TODAY IN SE OK/WRN AR...THINK
THERE IS A DECENT CHANCE OF A CONVECTIVE LINE FORMING BY LATE
AFTERNOON OR EARLY EVENING.  COULD SEE SOME ISOLATED DAMAGING WINDS.

MESOETA DOES...HOWEVER...REDEVELOP THUNDERSTORMS ACROSS SE KS/NE OK
LATER TODAY...IN ASSOCIATION WITH SURFACE LOW AND MID-LEVEL COLD
CORE (H5 TEMPS AROUND -25C).  MOST OF THE ACTIVITY SHOULD MOVE OUT
OF THE AREA BY MIDNIGHT.

OVERALL...CANT ARGUE TOO MUCH WITH SPC DAY 1 CONVECTIVE OUTLOOK.
COULD BE INTERESTING FOR A FEW HOURS.

ANY WRAPAROUND MOISTURE WILL EXIT THE AREA BY EARLY
WEDNESDAY...GIVING WAY TO PARTLY CLOUDY/MOSTLY SUNNY SKIES.  NOTED
THAT MESOETA/AVN SPIT OUT SOME LIGHT PRECIP WEDNESDAY NIGHT AS
ANOTHER WEAK BOUNDARY APPROACHES...BUT WILL KEEP THE FORECAST DRY
FOR NOW.

COOLER WEATHER ON TAP FOR THURSDAY AS HIGH PRESSURE BUILDS INTO THE
SRN PLAINS.

FRIDAY AND SATURDAY ARE LOOKING QUITE MILD AS WLY H85 FLOW
DEVELOPS.  AVN CONTINUES TO SHOW VERY WARM H85 TEMPS BY SATURDAY
(AROUND 12-13C)...SO PLAN ON KEEPING TEMPS WELL ABOVE NORMAL.

WILL KNOCK BACK TEMPS ON MONDAY AS POLAR FRONT MOVES INTO THE
AREA.

FCSTID = 18
TUL   71  42  63  39 /  70  30   0  10
FSM   68  43  62  38 /  80  50   0  10
MLC   71  43  64  39 /  80  40   0  10
BVO   71  40  63  38 /  60  20   0  10
FYV   66  41  58  35 /  80  50   0  10
BYV   66  41  58  35 /  80  50   0  10
MIO   70  40  60  36 /  80  40   0  10
MKO   71  42  63  38 /  80  30   0  10
F10   71  42  63  39 /  70  30   0  10
HHW   71  44  64  41 /  80  30   0  10

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

ARZ001-002-010-011-019-020-029-OKZ049-053>076-201200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
600 AM CST TUE FEB 19 2002

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED TODAY AND TONIGHT OVER
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...

AN AREA OF SHOWERS AND THUNDERSTORM OVER EASTERN OKLAHOMA THIS
MORNING WILL CONTINUE TO PUSH EASTWARD INTO WESTERN ARKANSAS EARLY
THIS MORNING. THE THUNDERSTORMS ARE EXPECTED TO COME TO AN END IN
EASTERN OKLAHOMA BY MID MORNING...AND IN WESTERN ARKANSAS BY EARLY
AFTERNOON. SOME OF THESE STORMS COULD BECOME SEVERE WITH LARGE HAIL
POSSIBLE.

ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND EAST OF
HIGHWAY 75 LATE THIS AFTERNOON. THESE STORMS ARE EXPECTED TO DEVELOP
INTO A LINE OF THUNDERSTORMS...THE STRONGEST OF WHICH WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND STRONG DAMAGING WINDS. ALL OF
THIS THUNDERSTORM ACTIVITY WILL SPREAD INTO WESTERN ARKANSAS DURING
THE EVENING HOURS.

THE SEVERE WEATHER THREAT WILL COME TO AN END BY EARLY WEDNESDAY
MORNING ACROSS ALL OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.

.SPOTTER ACTIVATION...
SPOTTER ACTIVATION WILL LIKELY BE REQUIRED BY AFTERNOON OVER EASTERN
OKLAHOMA AND BY EARLY EVENING IN WESTERN ARKANSAS.

.DISCUSSION...
A STRONG UPPER LEVEL JET WAS MOVING THROUGH WESTERN OKLAHOMA THIS
MORNING. LOW LEVEL MOISTURE FROM THE GULF OF MEXICO WAS SURGING
NORTH AHEAD OF THIS FEATURE. A STRONG LOW LEVEL JET WILL CONTINUE
THROUGH THE MORNING HOURS...ALLOWING ELEVATED THUNDERSTORM ACTIVITY
OVER THE AREA TO CONTINUE. FAVORABLE WIND SHEAR AND TEMPERATURE
PROFILES SUGGEST THIS ACTIVITY WILL HAVE THE POTENTIAL TO PRODUCE
ISOLATED LARGE HAIL BEFORE WEAKENING AND MOVING EAST OF THE AREA
EARLY THIS AFTERNOON.

THIS AFTERNOON...AS A COLD FRONT APPROACHES FROM THE WEST...A LINE
OF THUNDERSTORMS IS EXPECTED TO DEVELOP ALONG OR NEAR THE HIGHWAY 75
CORRIDOR. INSTABILITY WILL BE MODERATE THIS AFTERNOON...WITH CAPE
VALUES APPROACHING 1500 J/KG. STRONG SPEED SHEAR WILL ALSO BE
REALIZED BY AFTERNOON. LOW AND MID LEVEL LAPSE RATES WILL BECOME
VERY STEEP AS WELL. THESE FACTORS COMBINE TO SUGGEST THE THREAT FROM
THIS AFTERNOON/S THUNDERSTORM ACTIVITY WILL PRIMARILY BE DAMAGING
WINDS AND LARGE HAIL.

IF SURFACE WINDS BACK SUFFICIENTLY THIS AFTERNOON AHEAD OF AN
APPROACHING WAVE ON THE COLD FRONT...LOW LEVEL WIND SHEAR WOULD BE
MAXIMIZED. THIS WOULD SUGGEST AN INCREASED POTENTIAL FOR ISOLATED
TORNADOES...MAINLY ACROSS NORTHERN SECTIONS. AT THIS TIME...IT
APPEARS LOW LEVEL WINDS WILL REMAIN MORE SOUTHERLY...LIMITING THE
TORNADO THREAT.

THREAT TABLE
VALID THROUGH 1200 UTC WEDNESDAY

THREAT AREA 1...EASTERN OKLAHOMA AND NORTHWEST ARKANSAS EAST OF
HIGHWAY 75
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...70
SIGNIFICANT SEVERE WEATHER PROBABILITY IF STORMS OCCUR...20

THREAT AREAS DEFINE THE GREATEST RISK. PROBABILITIES ARE IN PERCENT.
SIGNIFICANT SEVERE WEATHER IS DEFINED AS F1 OR GREATER WIND/TORNADO
DAMAGE AND/OR GOLFBALL SIZE HAIL OR LARGER.

AN UPDATED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED BY AROUND 100 PM
THIS AFTERNOON.

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

MANNING