Severe Thunderstorm Warning 87, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
320 PM CDT SUN APR 22 2001

LATEST SATL LOOP SHOWING STRONG UPPER SYSTEM MOVING FROM EASTERN CO
NORTHEASTWARD INTO WESTERN NEB/KS.  SURFACE LOW WAS LOCATED OVER
WESTERN KS AT 20Z...AND WILL BE LIFTING QUICKLY TO THE NORTHEAST
TOWARD IA/MN THROUGH THE NIGHT.  BROKEN LINE OF STRONG/SEVERE
CONVECTION HAS BEEN OCCURRING ALONG TRAILING DRYLINE/FRONT THROUGH
THE AFTERNOON ACROSS WESTERN AND CENTRAL KS/OK.  WILL CONTINUE TO
SEE THIS LINE ADVANCE INTO THE AREA THROUGH THE EVENING.  LINE HAS
BEEN WEAKENING OVER THE PAST HOUR OR SO...BUT STILL POTENTIAL FOR
MAINLY SOME STRONG WINDS.  WILL KEEP LIKELY POPS GOING ACROSS THE
AREA THROUGH THE NIGHT.  ALSO STILL EXPECT TO SEE SOME FURTHER
BUILDING ON THE SOUTHERN EXTENT OF THE LINE.

WILL KEEP SOME LINGERING LOW POPS IN THE FAR EASTERN AND SOUTHERN
ZONES FOR EARLY MONDAY MORNING...THEN DRY WEATHER WILL PREVAIL
THROUGH THE REMAINDER OF THE UPCOMING WEEK AS UPPER RIDGE BUILDS IN
AND DOMINATES.  A SHORT COOL SPELL IN STORE BEHIND THIS SYSTEM
TOMORROW/TOMORROW NIGHT BEFORE TEMPS REBOUND AGAIN AS UPPER RIDGE
BUILDS IN.

FCSTID = 4
TUL   57  66  45  72 /  70  10   0   0
FSM   63  70  43  74 /  60  30  10   0
MLC   60  70  45  74 /  70  10   0   0
BVO   53  65  41  72 /  70  10   0   0
FYV   58  67  41  70 /  60  30   0   0
BYV   58  67  41  70 /  60  30    0   0
MIO   57  66  41  70 /  70  10   0   0
MKO   57  66  44  73 /  70  10   0   0
F10   57  66  45  72 /  70  10   0   0
HHW   62  70  45  74 /  60  30  10   0

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

ARZ001-002-010-011-019-020-029-OKZ049-053>076-231100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
100 PM CDT SUN APR 22 2001

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON AND
   TONIGHT IN EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...

A STRONG UPPER LEVEL STORM CENTERED OVER NORTHEAST NEW MEXICO AT
MIDDAY WILL MOVE NORTHEAST INTO NORTHEAST NEBRASKA BY MONDAY
MORNING. LOW PRESSURE AT THE SURFACE OVER SOUTHEAST COLORADO WILL
MOVE INTO SOUTHERN MINNESOTA BY MONDAY MORNING. A COLD FRONT
TRAILING SOUTH FROM THE LOW WILL MOVE ACROSS EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS LATE TONIGHT INTO EARLY MONDAY.

A LINE OF STRONG TO SEVERE THUNDERSTORMS WAS LOCATED OVER WESTERN
OKLAHOMA AT MIDDAY.  IT WILL MOVE NORTHEAST AND APPROACH NORTHEAST
OKLAHOMA LATE THIS AFTERNOON AND MOVE ACROSS THE REST OF THE AREA
THIS EVENING AND DURING THE EARLY MORNING HOURS. DAMAGING WINDS WILL
BE THE MAIN SEVERE WEATHER THREAT WITH THESE STORMS BUT A TORNADO OR
TWO MAY ALSO OCCUR. A FEW OF THE STORMS MAY ALSO PRODUCE HAIL UP TO
QUARTER SIZE...MAINLY IN EASTERN OKLAHOMA.

.SPOTTER ACTIVATION...
EMERGENCY MANAGEMENT AGENCIES AND STORM SPOTTER GROUPS THROUGHOUT
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS WILL LIKELY REQUIRE
ACTIVATION BY LATE THIS AFTERNOON OR EVENING.

.DISCUSSION...
LARGE SCALE LIFT IN ASSOCIATION WITH THE STRONG UPPER LEVEL STORM
HAS HELPED COOL TEMPERATURES ALOFT OVER WESTERN OKLAHOMA ENOUGH TO
BREAK THE STRONG CAP THAT HAS BEEN IN PLACE THIS WEEK.  DESPITE
CONSIDERABLE CLOUD COVER...INSTABILITY WILL BE SUFFICIENT FOR A FEW
SEVERE THUNDERSTORMS ALONG THE SQUALL LINE WHICH WILL MOVE NORTHEAST
INTO EASTERN OKLAHOMA LATE THIS AFTERNOON OR EARLY THIS EVENING.  A
FEW ISOLATED STORMS MAY DEVELOP AHEAD OF THE SQUALL LINE TODAY BUT
THESE STORMS WILL LIKELY REMAIN ELEVATED IN NATURE. INSTABILITY WILL
BE MORE MARGINAL IN NORTHWEST ARKANSAS SO STORMS WILL LIKELY BE
WEAKENING AS THEY MOVE INTO THIS AREA OVERNIGHT. FORECAST WIND
FIELDS SUPPORT MAINLY A DAMAGING WIND THREAT FROM THE STORMS
ALTHOUGH A TORNADO OR TWO MAY OCCUR IN ASSOCIATION WITH INDIVIDUAL
STORMS NEAR BREAKS IN THE LINE.  LARGE HAIL MAY ALSO OCCUR WITH A
FEW OF THE STRONGER STORMS WITHIN THE LINE.

THREAT TABLE
VALID THROUGH 6 AM MONDAY
THREAT AREA 1...ALL OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...100
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...50

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.

.OTHER HAZARDS...
A WIND ADVISORY HAS BEEN ISSUED FOR ALL OF EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS FOR TODAY DUE TO STRONG AND GUSTY SOUTH WINDS.
THESE WINDS WILL ALSO RESULT IN A VERY HIGH FIRE DANGER TODAY. MORE
INFORMATION CAN BE FOUND IN THE PRODUCTS /OKCNPWTUL/ AND /OKCFWMTUL/.

MORE DETAILED WEATHER INFORMATION...INCLUDING A GRAPHICAL VERSION OF
THIS OUTLOOK CAN BE FOUND AT: WWW.SRH.NOAA.GOV/TEULSA.