Severe Thunderstorm Warning 221, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
1110 PM CDT TUE MAY 29 2001

SENT A QUICK UPDATE OUT FOR ADDITION OF TORNADO WATCH UNTIL 400 AM.
ALSO ADDED oHEAVY RAIN WORDING TO FLASH FLOOD WATCH ZONES.

HOWIESON
FCSTID = 44

.TSA...
AR...NONE.
OK...FLASH FLOOD WATCH FOR THIS EVENING THROUGH WEDNESDAY MORNING FOR
ZONES OKZ054>068...OKZ070>071.

ARZ001-002-010-011-019-020-029-OKZ049-053>076-301100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TULSA OK
950 PM CDT TUE MAY 29 2001

...A FEW SEVERE THUNDERSTORMS EXPECTED TONIGHT...

SEVERAL CLUSTERS OF STRONG TO SEVERE THUNDERSTORMS HAD DEVELOPED
THIS EVENING ACROSS KANSAS AND WESTERN OKLAHOMA. CONDITIONS ARE
FAVORABLE FOR THUNDERSTORMS TO SPREAD INTO EASTERN OKLAHOMA BEFORE
MIDNIGHT...AND INTO NORTHWEST ARKANSAS BY 2 AM. A FEW OF THE
THUNDERSTORMS ARE LIKELY TO BE SEVERE OVERNIGHT...WITH NICKEL SIZE
HAIL AND WIND GUSTS UP TO 70 MPH POSSIBLE.

ADDITIONAL SEVERE WEATHER IS POSSIBLE OVER MUCH OF THE AREA
WEDNESDAY AFTERNOON.

.SPOTTER ACTIVATION...
SPOTTERS ACROSS MUCH OF EASTERN OKLAHOMA WILL LIKELY NEED TO BE
ACTIVATED BEFORE MIDNIGHT. SPOTTER ACTIVATION MAY BE REQUIRED IN
NORTHWEST ARKANSAS BY 2 AM.

.DISCUSSION...
ELEVATED CAPES OF UP TO 2000 J/KG AND FAVORABLE DEEP LAYER WIND
SHEAR WILL SUPPORT A CONTINUED EVOLUTION OF STRONG CONVECTION IN THE
WARM ADVECTION REGIME. CONDITIONS ARE FAVORABLE FOR A LARGE COMPLEX
OF THUNDERSTORMS TO MOVE ACROSS EASTERN OKLAHOMA AND NORTHWEST
ARKANSAS TONIGHT. BOW SEGMENTS...MAINLY ALONG THE LEADING EDGE OF
THE EASTWARD MOVING THUNDERSTORM COMPLEX...WILL PRODUCE LOCAL WIND
GUSTS OF 60 TO 70 MPH. A LOW LEVEL JET OF 50 KNOTS WILL EXTEND FROM
SOUTH CENTRAL OKLAHOMA INTO NORTHEAST OKLAHOMA DURING THE LATE NIGHT
AND EARLY MORNING HOURS...WHICH IS A FAVORABLE PATTERN FOR EXCESSIVE
RAINS ACROSS NORTHEAST OKLAHOMA.

THREAT TABLE
VALID THROUGH 6 AM WEDNESDAY

THREAT AREA 1...ALL OF EASTERN OKLAHOMA
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...90
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...25

THREAT AREA 2...NORTHWEST ARKANSAS
THUNDERSTORM PROBABILITY...70
SEVERE PROBABILITY IF STORMS OCCUR...30
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...
A FLASH FLOOD WATCH IS IN EFFECT FOR TONIGHT AND WEDNESDAY MORNING
FOR MOST OF NORTHEAST OKLAHOMA. THE FLASH FLOOD WATCH MESSAGE
/OKCFFATUL/ ISSUED AT 935 PM GIVES DETAILS ON THE HEAVY RAIN THREAT.

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