Hail and Damaging Winds in Oklahoma, September 7 to 8, 2001

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
330 PM CDT FRI SEP 7 2001

WILL SEE A COUPLE OF SHOTS AT SEVERE WEATHER AND POTENTIALLY SOME
HEAVY RAIN OVER THE AREA THE NEXT FEW DAYS.  FIRST ROUND JUST NOW
BEGINNING TO THE WEST AS STRONG SHORTWAVE MOVING FROM CO/NM INTO KS
AND OK PANHANDLE STARTING TO FIRE SOME STORMS ALONG
COLDFRONT/DRYLINE.  ACTIVITY EXPECTED TO FORM INTO A SQUALL LINE
THAT WILL MOVE ACROSS THE AREA TONIGHT.  POTENTIAL FOR SEVERE
WEATHER WILL BE GREATEST OVER NORTHEAST OK THROUGH THE
EVENING...WITH STORMS EXPECTED TO BE WEAKENING SOME AS THEY MOVE
INTO NORTHWEST AR AND SOUTHEAST OK LATER TONIGHT.  ALSO SOME CONCERN
FOR HEAVY RAIN...BUT WITH DRY CONDITIONS OF THE RECENT PAST AND
STORMS MOVING QUICKLY...SHOULD SEE NO WIDESPREAD PROBLEMS.
SOMETHING TO KEEP IN MIND THOUGH IF ADDITIONAL HEAVY RAINS
MATERIALIZE SATURDAY NIGHT/SUNDAY.

FIRST SHORTWAVE WILL LIFT QUICKLY TO THE NORTHEAST TONIGHT WITH
SECOND SHORTWAVE EVIDENT ON WATER VAPOR DIVING SOUTHWARD FROM ID/MT
THROUGH THE ROCKIES.  WITH FIRST SHORTWAVE QUICKLY MOVING OFF TO THE
NORTHEAST...COLD FRONT IS EXPECTED TO HANG UP SOMEWHERE OVER THE
AREA TILL SECOND SHORTWAVE MOVES ACROSS THE AREA SATURDAY NIGHT AND
SUNDAY.

WILL GO WITH CATEGORICAL OR LIKELY POPS FOR TONIGHT...THEN CHANCE
POPS AREAWIDE DURING THE DAY ON SATURDAY.  AREA WILL BE BETWEEN THE
TWO SYSTEMS FOR MUCH OF THE DAY ON SATURDAY...BUT WITH FRONT
EXPECTED TO STRETCH ACROSS THE AREA AT LEAST SOME LOW POPS
WARRANTED.  LIKELY POPS THEN AGAIN SATURDAY NIGHT AND SUNDAY AS
SECOND SYSTEM SWINGS THROUGH THE AREA WITH POTENTIAL FOR SEVERE
WEATHER OR HEAVY RAIN POSSIBLE AGAIN.

BEYOND SUNDAY...FORECAST LOOKS DRY AS UPPER RIDGE BUILDS BACK IN.

FCSTID = 4
TUL   68  85  68  75 /  80  30  70  60
FSM   68  88  70  78 /  70  40  60  70
MLC   71  88  70  77 /  70  40  60  70
BVO   66  82  65  73 /  80  30  70  60
FYV   68  84  66  74 /  80  40  70  70
BYV   69  84  67  74 /  80  40  70  70
MIO   68  84  66  74 /  80  30  70  60
MKO   68  85  68  75 /  80  30  70  60
F10   68  85  68  75 /  80  30  70  60
HHW   72  88  70  78 /  60  30  60  70

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

ARZ001-002-010-011-019-020-029-OKZ049-053>076-081100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
105 PM CDT FRI SEP 7 2001

...NUMEROUS SEVERE THUNDERSTORMS ARE EXPECTED IN PARTS OF NORTHEAST
OKLAHOMA THIS EVENING...

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE REST OF
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS TONIGHT...

A STRONG UPPER LEVEL STORM SYSTEM LOCATED OVER SOUTHEAST COLORADO
EARLY THIS AFTERNOON WILL MOVE EAST INTO THE OKLAHOMA PANHANDLE BY
THE LATE AFTERNOON HOURS BEFORE LIFTING RAPIDLY NORTHEAST AND
WEAKENING OVERNIGHT. SURFACE LOW PRESSURE WILL DEEPEN BY LATE
AFTERNOON ALONG THE OKLAHOMA/KANSAS BORDER NORTH OF ENID AND MOVE
NORTHEAST TO SOUTHERN IOWA LATE TONIGHT. A COLD FRONT WILL EXTEND
SOUTHWEST FROM THE LOW AND WILL MOVE SLOWLY EAST INTO NORTHEAST
OKLAHOMA TONIGHT.

SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP IN NORTH CENTRAL
OKLAHOMA AND SOUTHERN KANSAS LATE THIS AFTERNOON AND MOVE NORTHEAST
INTO NORTHEAST OKLAHOMA THIS EVENING. LARGE HAIL TO BASEBALL
SIZE...DAMAGING WINDS TO 80 MILES AN HOUR AND ISOLATED TORNADOES MAY
OCCUR TO THE WEST OF A BARTLESVILLE TO BRISTOW LINE BETWEEN 6 PM AND
11 PM THIS EVENING. THE BEST CHANCE FOR TORNADOES IN THE OUTLOOKED
AREA WILL BE BETWEEN 6 AND 9 PM.

THUNDERSTORMS WILL WEAKEN TOWARDS MIDNIGHT AS THE UPPER LEVEL STORM
MOVES NORTHEAST AWAY FROM THE AREA. HOWEVER...A FEW STORMS WILL
STILL LIKELY PRODUCE DAMAGING WIND GUSTS OF 60 TO 70 MILES AN HOUR
LATER TONIGHT AS THEY MOVE EAST INTO NORTHWEST ARKANSAS AND
SOUTHEAST OKLAHOMA.

.SPOTTER ACTIVATION...
EMERGENCY MANAGEMENT AGENCIES AND STORM SPOTTER GROUPS IN NORTHEAST
OKLAHOMA WILL LIKELY NEED TO BE ACTIVATED BY 6 PM THIS EVENING.
SPOTTER ACTIVATION WILL BE LIKELY AFTER 11 PM IN NORTHWEST ARKANSAS
AND SOUTHEAST OKLAHOMA.

THE COLD FRONT IS EXPECTED TO STALL ACROSS NORTHEAST OKLAHOMA
SATURDAY AS ANOTHER UPPER LEVEL STORM APPROACHES FROM THE WEST.
SEVERE THUNDERSTORMS WILL LIKELY REDEVELOP ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS LATE SATURDAY AFTERNOON AND CONTINUE INTO
SATURDAY NIGHT.

.DISCUSSION...
CLOUDS WILL CONTINUE TO BREAK UP THIS AFTERNOON ALLOWING STRONG
HEATING WITH TEMPERATURES WARMING INTO THE 90S AHEAD OF THE COLD
FRONT. WARM TEMPERATURES ALOFT WILL PREVENT THUNDERSTORM DEVELOPMENT
IN EASTERN OKLAHOMA AND NORTHWEST ARKANSAS DURING THE AFTERNOON.
COOLING ALOFT ASSOCIATED WITH THE STRONG UPPER LEVEL SYSTEM AND
STRONG CONVERGENCE EAST OF THE SURFACE LOW AND ALONG THE COLD FRONT
WILL RESULT IN EXPLOSIVE THUNDERSTORM DEVELOPMENT LATER THIS
AFTERNOON...ROUGHLY ALONG AN ENID OKLAHOMA TO WICHITA KANSAS LINE.

THESE STORMS WILL QUICKLY BECOME SEVERE WITH THE POTENTIAL FOR
SUPERCELLULAR STORMS WITH VERY LARGE HAIL...DAMAGING WINDS AND
POSSIBLY ISOLATED TORNADOES. THESE STORMS WILL MOVE NORTHEAST INTO
WESTERN SECTIONS OF OSAGE AND PAWNEE COUNTIES BY EARLY EVENING.

AS THE EVENING WEARS ON...STORMS WILL BECOME MORE LINEAR IN NATURE
WITH A GRADUAL WEAKENING TREND. THE LARGE HAIL AND TORNADO THREAT
WILL END BY AROUND MIDNIGHT...BUT DAMAGING WINDS WILL REMAIN LIKELY
WITH A FEW STORMS WELL PAST MIDNIGHT.

THREAT TABLE
VALID THROUGH 7 AM SATURDAY

THREAT AREA 1...WEST OF A LINE FROM BARTLESVILLE TO BRISTOW
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...100
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...80

THREAT AREA 2...WEST OF A LINE FROM JAY TO OKMULGEE
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...100
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...60

THREAT AREA 3...EAST OF A LINE FROM JAY TO OKMULGEE
THUNDERSTORM PROBABILITY...80
SEVERE PROBABILITY IF STORMS OCCUR...60
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...30

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 WIND ADVISORY IS IN EFFECT FOR MOST OF NORTHEAST OKLAHOMA THIS
AFTERNOON. REFER TO /OKCNPWTUL/ FOR FURTHER INFORMATION ON THE WIND
ADVISORY.

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