Severe Thunderstorm Warning 141, NWS Tulsa, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
250 AM CDT FRI MAY 1 2009

.DISCUSSION...
ISOLATED SUPERCELL MOVING THROUGH FAR NORTHEAST OKLAHOMA WITH A
WIND/LARGE HAIL THREAT. FURTHER SOUTH AND WEST...WARMER
TEMPERATURES ALOFT HAVE SUPPRESSED CONVECTION ALONG RESIDUAL
OUTFLOW BOUNDARY...LOCATED OVER NORTH CENTRAL OKLAHOMA...EXTENDING
SOUTHEAST TO NEAR FORT SMITH. GIVEN LATEST TRENDS...THUNDERSTORMS
MAY REMAIN ACROSS FAR NORTHEAST OKLAHOMA WITH STORMS POSSIBLY
MOVING INTO FAR NORTHWEST ARKANSAS BY SUNRISE. IF THIS
OCCURS...ADDITIONAL SURFACE HEATING/DESTABILIZATION WILL LIKELY
OCCUR AHEAD OF COLD FRONT...WHICH IS FORECAST TO MOVE INTO FAR
NORTHEAST OKLAHOMA LATE THIS MORNING...PUSHING SOUTH TO NEAR THE
INTERSTATE 44 CORRIDOR BY LATE AFTERNOON. ANY STORMS THAT DEVELOP
THIS AFTERNOON ALONG BOUNDARY WOULD HAVE THE POTENTIAL TO BECOME
SEVERE WITH LARGE HAIL AND DAMAGING WINDS. THUNDERSTORMS THAT
DEVELOP ACROSS SOUTHWEST OKLAHOMA LATE THIS AFTERNOON...WILL
LIKELY FORM INTO A MCS THIS EVENING...POSSIBLY AFFECTING PORTIONS
OF SOUTHEAST OKLAHOMA INTO THE OVERNIGHT HOURS.

FLASH FLOOD GUIDANCE REMAINS RELATIVELY LOW ACROSS PORTIONS OF
EASTERN OKLAHOMA FROM PREVIOUS HEAVY RAINFALL. GIVEN THE POTENTIAL
FOR MULTIPLE ROUNDS OF HEAVY PRECIPITATION TODAY THROUGH SUNDAY
WILL GO AHEAD AND ISSUE A FLASH FLOOD WATCH FOR THIS TIME PERIOD.
ALTHOUGH EXACT TIMING/LOCATIONS/AMOUNTS WILL STILL BE DIFFICULT
TO PIN DOWN BEYOND 24 HOURS...A SUBSTANTIAL FLOOD THREAT WILL
LIKELY DEVELOP OVER MUCH OF THE AREA INTO THE WEEKEND.

ECMWF/GFS IN FAIRLY GOOD AGREEMENT IN PUSHING COLD FRONT INTO
SOUTHEAST OKLAHOMA/WEST CENTRAL ARKANSAS BY SATURDAY MORNING WITH
THUNDERSTORMS LIKELY ALONG/NORTH OF THE FRONT WITH THE POTENTIAL
FOR HEAVY RAINFALL. BOUNDARY WILL LIKELY STALL ACROSS THIS AREA ON
SATURDAY AS UPPER DISTURBANCE APPROACHES FROM THE WEST. IN
RESPONSE TO UPPER FEATURE...SURFACE WAVE WILL LIKELY DEVELOP ALONG
FRONTAL BOUNDARY ON SUNDAY WITH THUNDERSTORMS/HEAVY RAIN FINALLY
SHIFTING EAST BY MONDAY.

REMAINDER OF FORECAST STAYED WITH A BLEND OF THE ECMWF/GFS AS NEXT
UPPER WAVE MOVES THROUGH THE SOUTHERN PLAINS AROUND MID WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   71  54  60  52 /  70  70  90  90
FSM   78  62  74  59 /  50  60  80  80
MLC   77  62  72  55 /  40  60  60  70
BVO   66  52  59  48 /  70  70  90  80
FYV   72  58  69  55 /  60  70  90  80
BYV   71  53  59  50 /  70  70  90  80
MKO   73  58  62  53 /  70  70  90  80
MIO   68  51  59  49 /  70  70  90  80
F10   76  57  60  52 /  60  60  80  80
HHW   80  65  77  64 /  30  60  50  60

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH FROM 7 AM FRIDAY TO 7 PM SUNDAY FOR OKZ049-
     OKZ053-OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-
     OKZ061-OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-
     OKZ069-OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.

AR...FLASH FLOOD WATCH FROM 7 AM FRIDAY TO 7 PM SUNDAY FOR ARZ001-
     ARZ002-ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.

&&

SHORT TERM...22
LONG TERM....12

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
951 PM CDT THU APR 30 2009

ARZ001-002-010-011-019-020-029-OKZ049-053>076-011000-
ADAIR OK-BENTON AR-CARROLL AR-CHEROKEE OK-CHOCTAW OK-CRAIG OK-
CRAWFORD AR-CREEK OK-DELAWARE OK-FRANKLIN AR-HASKELL OK-LATIMER OK-
LE FLORE OK-MADISON AR-MAYES OK-MCINTOSH OK-MUSKOGEE OK-NOWATA OK-
OKFUSKEE OK-OKMULGEE OK-OSAGE OK-OTTAWA OK-PAWNEE OK-PITTSBURG OK-
PUSHMATAHA OK-ROGERS OK-SEBASTIAN AR-SEQUOYAH OK-TULSA OK-WAGONER OK-
WASHINGTON OK-WASHINGTON AR-
951 PM CDT THU APR 30 2009

...SEVERE WEATHER AND HEAVY RAIN POTENTIAL CONTINUE FOR DAYS...

THIS OUTLOOK IS FOR NORTHWEST AND WEST CENTRAL ARKANSAS AS WELL AS
MUCH OF EASTERN OKLAHOMA.

.DAY ONE...TONIGHT.

SEVERE THUNDERSTORM.
RISK...LIMITED.
AREA...PRIMARILY NORTHEAST OKLAHOMA.
ONSET...AFTER 2 AM.

DISCUSSION...
THUNDERSTORMS ARE EXPECTED TO DEVELOP AGAIN LATE TONIGHT IN
VICINITY OF A SLOW MOVING FRONTAL BOUNDARY.  THESE STORMS
WILL TRACK EASTWARD INTO NORTHEAST OKLAHOMA AND POSE A
LIMITED RISK OF SEVERE WEATHER...ALONG WITH LOCALLY HEAVY
RAINS.  THE MORE WIDESPREAD AND SIGNIFICANT RAINFALL IS
LIKELY TO OCCUR FRIDAY INTO SATURDAY.

SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT...
LOCAL SPOTTER ACTIVATION MAY BE NEEDED...HOWEVER A REGIONAL
SPOTTER NETWORK IS NOT ANTICIPATED.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
FRIDAY...THUNDERSTORM POTENTIAL...HEAVY RAIN POTENTIAL.
SATURDAY...THUNDERSTORM POTENTIAL...HEAVY RAIN POTENTIAL.
SUNDAY...SEVERE THUNDERSTORM POTENTIAL.
MONDAY THROUGH WEDNESDAY...THUNDERSTORM POTENTIAL.

EXTENDED DISCUSSION...
THUNDERSTORM CHANCES CONTINUE DAILY THROUGH THE UPCOMING WEEK
WITH HEAVY RAINFALL LIKELY ACROSS MUCH OF EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS.  SEVERE WEATHER WILL ALSO BE POSSIBLE
AS STRONG INSTABILITY REMAINS AHEAD OF A SLOW MOVING FRONTAL
BOUNDARY.  THE DEVELOPING WEATHER PATTERN FOR THE UPCOMING
WEEK IS LIKELY TO SUPPORT SEVERAL ROUNDS OF SEVERE WEATHER...
ALONG WITH AREAS OF EXCESSIVE RAINFALL LEADING TO A HEIGHTENED
FLASH FLOOD POTENTIAL FOR THE ENTIRE FORECAST AREA.

EMERGENCY MANAGEMENT PLANNING STATEMENT...
AN ACTIVE WEATHER PATTERN WILL REMAIN PLACE OVER THE UPCOMING
WEEK...WITH WEATHER RELATED RESPONSES LIKELY ONE OR MORE TIMES
DUE TO SEVERE WEATHER AND FLOODING POTENTIAL.

WWW.SRH.NOAA.GOV/TULSA CONTAINS ADDITIONAL TABULAR AND GRAPHICAL
INFORMATION.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
1225 AM CDT FRI MAY 1 2009

OKZ054-059-010615-
OSAGE OK-PAWNEE OK-
1225 AM CDT FRI MAY 1 2009

...SIGNIFICANT WEATHER ALERT...

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A
SIGNIFICANT WEATHER ALERT EFFECTIVE UNTIL 115 AM CDT
FOR THE FOLLOWING COUNTIES...

IN NORTHEAST OKLAHOMA
     WESTERN OSAGE AND PAWNEE

AT 1225 AM CDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 21
MILES WEST OF PAWNEE...MOVING NORTHEAST AT 35 MPH. SOME LOCATIONS
THAT WILL BE AFFECTED BY THIS STORM INCLUDE...FAIRFAX...PAWNEE...
BLACKBURN...SKEDEE AND RALSTON.

RESIDENTS IN THESE AREAS SHOULD REMAIN ALERT IN CASE THE SIGNIFICANT
WEATHER ALERT IS UPGRADED TO A WARNING.

LAT...LON 3654 9699 3656 9690 3659 9690 3660 9693
      3658 9699 3659 9702 3674 9676 3625 9645
      3625 9692 3633 9692 3635 9703 3651 9704
TIME...MOT...LOC 0525Z 245DEG 28KT 3637 9718