Damaging Wind in Oklahoma, August 13, 2002

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OKLAHOMA
325 AM CDT TUE AUG 13 2002

...RETRANSMISSION

COLD-POOL DRIVEN MCS MOVED INTO NE OK MUCH QUICKER THAN ANY OF THE
NUMERICAL MODELS (AND THIS FORECASTER) HAD ANTICIPATED. NRN END
CONTINUES TO SLOWLY WEAKEN OVER NE OK WITH GUST FRONT CURRENTLY
MOVING INTO TULSA...WHILE LOW-LEVEL JET IS MAINTAINING STRONG STORMS
ALG ITS SRN EDGE IN CNTRL OK. SYNOPTIC COLD FRONT IS STILL WELL N
OF THE FORECAST AREA...STRETCHING FROM SRN IA-SCNTRL KS-TX PANHANDLE
AT 08Z. HAVE NOTED AN INCREASE IN POST-FRONTAL CONVECTION OVER KS
DURING THE PAST FEW HOURS...IN RESPONSE TO SHARP MID-LEVEL
TROF/LARGE SCALE UVV.

EXPECT INITIAL MCS TO CONTINUE TO WEAKEN THIS MORNING...LEAVING A
PRONOUNCED SFC BOUNDARY ACROSS THE FORECAST AREA.  EVOLUTION OF ANY
CONVECTIVE REDEVELOPMENT IS REALLY IN QUESTION...BUT CONDITIONS
REMAIN FAVORABE WITH CONVERGENCE ALONG SYNOPTIC/MESOSCALE BOUNDARIES
AND IMPRESSIVE LIFT AIDED BY RIGHT ENTRANCE REGION OF H25 JET. WONT
GET TOO FANCY WITH POPS TODAY...AND WILL GENERALLY BROADBRUSH LIKELY
POPS FOR MOST OF THE AREA.

WILL HAVE SOME LINGERING PRECIP OVER SE OK/WRN AR MAINLY THIS
EVENING...OTHERWISE DRIER AND MORE STABLE AIR WILL FILTER ACROSS THE
SRN PLAINS.

WEDNESDAY SHAPING UP TO BE A PLEASANT AUGUST DAY...WITH BELOW
AVERAGE TEMPS AND RELATIVE HUMIDITIES. WARM-UP WILL COMMENCE BY THU
AND CONTINUE INTO THE WEEKEND.

LITTLE IF ANY CHANGES MADE TO FORECAST PACKAGE BEYOND THURSDAY.

PRELIM NUMBERS...
TUL  80  62  87  65 /  70  20  10  10
FSM  88  65  88  66 /  70  40  10  10
MLC  87  66  88  66 /  70  40  10  10
BVO  80  60  87  63 /  70  20  10  10
FYV  81  61  84  58 /  70  40  10  10
BYV  79  59  82  62 /  70  40  10  10
MIO  78  59  84  63 /  70  20  10  10
MKO  83  63  87  66 /  70  20  10  10
F10  83  64  88  66 /  70  20  10  10
HHW  89  68  89  70 /  70  50  20  10

FORECAST ID = 18

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

OKZ054>067-131000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
425 AM CDT TUE AUG 13 2002

SEVERE THUNDERSTORM WATCH 601 THAT WAS IN EFFECT FOR...OSAGE...
WASHINGTON...NOWATA...OTTAWA...CRAIG...DELAWARE...ROGERS...PAWNEE...
MAYES...TULSA...CREEK...WAGONER...OKMULGEE AND OKFUSKEE COUNTIES...
HAS BEEN CANCELLED.

THUNDERSTORMS CONTINUE TO WEAKEN EARLY THIS MORNING ACROSS NORTHEAST
OKLAHOMA. LOCALLY HEAVY RAINFALL WILL OCCUR AND A FEW GUSTS TO 40
MPH ARE POSSIBLE...BUT THE THREAT OF SEVERE WEATHER HAS DIMINISHED.

ARZ001-002-010-011-019-020-029-OKZ049-053>076-141200-

EASTERN OKLAHOMA / NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
600 AM CDT TUE AUG 13 2002

...SEVERE THUNDERSTORMS POSSIBLE ACROSS EASTERN OKLAHOMA AND
   NORTHWEST ARKANSAS TODAY...

A WEAKENING LINE OF THUNDERSTORMS WILL CONTINUE TO PUSH ACROSS
EASTERN OKLAHOMA THIS MORNING...LEAVING AN OUTFLOW BOUNDARY OVER THE
AREA. ADDITIONAL STORMS WILL MOVE OUT OF SOUTHERN KANSAS LATER THIS
MORNING AS A COLD FRONT CONTINUES TO PUSH SOUTH ACROSS THE AREA.
THE INTERACTION OF THE FRONT AND OUTFLOW BOUNDARIES FROM OVERNIGHT
CONVECTION WILL PROVIDE FOCUS FOR ADDITIONAL STORMS TO DEVELOP
TODAY. INCREASING WIND SHEAR ASSOCIATED WITH AN UPPER LEVEL
DISTURBANCE MOVING ACROSS THE CENTRAL PLAINS WILL CAUSE SOME STORMS
TO BE SEVERE...ESPECIALLY ACROSS SOUTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS WHERE SURFACE HEATING WILL RAPIDLY DESTABILIZE THE
ATMOSPHERE.

.SPOTTER ACTIVATION...
SPOTTER ACTIVATION MAY BE NEEDED IN EASTERN OKLAHOMA AND NORTHWEST
ARKANSAS TODAY...ESPECIALLY SOUTH OF OF INTERSTATE 44 THIS AFTERNOON.

.DISCUSSION...
AN UNSEASONABLY STRONG COLD FONT PUSHING ACROSS OKLAHOMA AND
ARKANSAS TODAY WILL INTERACT WITH OUTFLOW BOUNDARIES ASSOCIATED WITH
OVERNIGHT CONVECTION. SURFACE-BASED CAPE VALUES UP TO 2500 J/KG WILL
DEVELOP MAINLY TO THE SOUTH OF THE INTERSTATE 44 CORRIDOR BY THIS
AFTERNOON WHERE SURFACE DEW POINTS REMAIN IN THE LOWER 70S.
ADDITIONAL LIFT WILL BE PROVIDED AS THIS AREA ALSO FALLS UNDER THE
RIGHT EXIT REGION OF A 70 KT SOUTHWESTERLY JET STREAK AHEAD OF A
SHARP UPPER TROUGH MOVING THROUGH THE CENTRAL PLAINS. THE MAIN
SEVERE THREAT WILL ONCE AGAIN BE DAMAGING WINDS AS STORMS SHOULD
EVOLVE INTO A LINE THIS AFTERNOON.

RISK TABLE
VALID THROUGH 1200 UTC TUESDAY

AREA 1...
PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...40
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...10

RISK 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 OR LARGER HAIL.

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