Severe Thunderstorm Warning 263, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
325 AM CDT THU JUN 21 2001

LARGE MCS ACROSS SE KS INTO CNTRL OK IS TAKING ITS TIME GETTING TO
THE FORECAST AREA...BUT WILL SPREAD OVER NE OK SHORTLY.  THIS
ACTIVITY HAS BEEN ON A GRADUAL WEAKENING TREND AS IT ENCOUNTERS
WEAKER WINDS ALOFT...BUT STILL COULD SEE AN ISOLATED HAILER OR TWO
EARLIER THIS MORNING.

TRUE COLD FRONT APPEARS TO BE OVER FAR SE KS INTO NW OK...WITH
EXTENSIVE OUTFLOW BOUNDARY ACROSS NE OK INTO CNTRL OK AND THE SRN TX
PANHANDLE.  REGARDLESS...OUTFLOW BOUNDARY WILL EFFECTIVELY BECOME
THE FRONT TODAY AND SHUD OUT OF SE OK BY THIS AFTERNOON AS STRONG
UPPER SHORTWAVE SWINGS THRU.  MAJORITY OF POPS WILL BE CONFINED TO
THIS MORNING...AND WILL TAKE A LAST LOOK AT RADAR BEFORE DECIDING ON
FIRST PERIOD POPS.

WILL LEAVE LINGERING POPS EARLY THIS EVENING FOR EXTREME SE
OK...OTHERWISE HIGH PRESSURE AND DRIER LOW-LEVEL AIR WILL FILTER
OVER ERN OK/NW AR.  DRIER AIR SHOULD REMAIN THRU THE
WEEKEND...YIELDING PLEASANT DAYTIME TEMPS AND COOL NIGHTS.  SFC
RIDGE AXIS SETS UP OVER THE AREA LATE FRI AND FRI NIGHT...AND
WOULDNT BE SURPRISED TO SEE SOME RECORD LOW TEMPS IN THE VALLEYS OF
NW AR.

WILL TAKE A LOOK AT NEW MRF...BUT NOT ANTICIPATING ANY CHANGES TO
THE REMAINDER OF THE EXTENDED.

FCSTID = 18

PRELIM NUMBERS...
TUL   80  59  83  58 /  50   0   0   0
FSM   81  59  85  55 /  70  10   0   0
MLC   80  58  84  57 /  70  10   0   0
BVO   80  56  83  56 /  40   0   0   0
FYV   76  52  80  50 /  70   0   0   0
BYV   76  52  80  50 /  70   0   0   0
MIO   78  55  82  54 /  50   0   0   0
MKO   79  57  83  56 /  70  10   0   0
F10   80  59  83  58 /  50   0   0   0
HHW   80  60  85  57 /  70  20   0   0

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

ARZ001-002-010-011-019-020-029-OKZ049-053>076-221100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
610 AM CDT THU JUN 21 2001

...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS THIS MORNING...

A COLD FRONT EXTENDED FROM SOUTHERN MISSOURI TO THE SOUTHWEST INTO
NORTHWEST OKLAHOMA THIS MORNING. SHOWERS AND THUNDERSTORMS HAVE BEEN
DEVELOPING IN THE VICINITY OF THIS BOUNDARY DURING THE OVERNIGHT
HOURS...AND HAVE BEEN MOVING EAST SOUTHEAST. THE STRONGEST STORMS ARE
EXPECTED TO TRACK ACROSS NORTHWEST ARKANSAS AND SOUTHEAST OKLAHOMA
THIS MORNING. THESE STORMS MAY BRIEFLY BECOME SEVERE...CAPABLE OF
PRODUCING LARGE HAIL AND GUSTY WINDS. STORMS WILL EXIT THE AREA BY
LATE THIS MORNING AS THE FRONT MOVES ACROSS THE AREA...THUS ENDING
THE SEVERE WEATHER THREAT.

.SPOTTER ACTIVATION...
ACTIVATION OF STORM SPOTTERS MAY BE NECESSARY THIS MORNING ACROSS
SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS.

.DISCUSSION...
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVERNIGHT IN RESPONSE TO
AND APPROACHING COLD FRONT. SUPPORT FROM AN UPPER LEVEL TROUGH
AXIS HAS SUSTAINED CONVECTION FOR MUCH OF THE OVERNIGHT PERIOD.
SHOWERS AND STORMS WILL CONTINUE MAINLY OUT AHEAD OF THE BOUNDARY
FOR MUCH OF THIS MORNING AS IT CONTINUES TO MOVE SOUTHEAST.
ENOUGH LIFT AND INSTABILITY MAY BE GENERATED FROM THE UPPER TROUGH
AXIS TO ALLOW ONE OR TWO STORMS TO BRIEFLY BECOME SEVERE...CAPABLE OF
PRODUCING LARGE HAIL AND GUSTY WINDS.

THREAT TABLE
VALID THROUGH 1100 UTC FRIDAY

THREAT AREA 1...SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...20
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...5

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

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