Hail and Damaging Winds in Oklahoma, May 18, 2001

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
255 AM CDT FRI MAY 18 2001

FORECAST FOR 1ST PERIOD HIGHLY DEPENDANT ON EVOLUTION OF CURRENT
CONVECTION. 00Z MESO-ETA WEAKENS STORMS ACROSS WESTERN OK AROUND 12Z
QUITE A BIT...BUT LATEST RADAR STILL SHOWS THEM LOOKING PRETTY
TOUGH. AIRMASS ACROSS SE OK IS PRIMED AND HAS NOT BEEN WORKED OVER
AS IT WAS OVER NE OK AND NW AR. COULD SEE ISOLATED SVR STORMS THIS
MORNING...MAINLY WIND GUSTS 60-70 MPH. SHOULD SEE SHRA/TSRA LIKELY
THIS AM THEN BECOMING PARTLY CLOUDY. IF STORMS FIZZLE BEFORE
ENTERING SE OK...THEN COULD SEE STORMS RE-FIRE THIS AFTERNOON JUST
ABOUT ANYWHERE. BEST CHC WILL BE ACROSS SE OK WHERE OUTFLOW
BOUNDARIES AND WEAK FRONT WILL LIKELY BE LOCATED. VERTICAL WIND
PROFILE DECENT BUT NOT IMPRESSIVE IN THE LOW LEVELS. SVR STORMS
SHOULD REMAIN ISOLATED.

BY TONIGHT...PRECIP WILL BE LONG GONE AND SOME CLEARING MAY OCCUR.
COULD SEE PATCHY FOG AS WELL AS COOL TEMPS. HAVE SIDED WITH COOLER
FWC AND PREV FCST NUMBERS FOR MINS.

NOT TOO OPTIMISTIC ABOUT RAIN CHCS ON SAT AND SAT NIGHT. OUTFLOW
BOUNDARY WILL BE LONG GONE AND SFC WINDS SHOULD VEER TO SE AHEAD OF
DEVELOPING SFC LOW. BEST STORMS SHOULD REMAIN TO THE WEST. COULD SEE
AN ISOLATED STORM IF STG WARM FRONT DEVELOPS.

MODELS DISAGREE ON STRENGTH OF UPR LOW TO EJECT OUT OF SW US...ETA
BRINGS OUT A POSITIVELY-TILTED S/W WHILE AVN KEEPS WAVE STRONGER AND
INTACT. BEST CHC OF PRECIP THIS WEEKEND WILL DEPEND ON TRACK AND
STRENGTH OF UPR LOW...LOOKS LIKE SUN AND SUN NIGHT WILL BE THE BEST
CHC. WILL GO AHEAD AND TAKE POPS UP TO LIKELY FOR SUN AND TAKE OUT
EARLY WORDING.

MONDAY SHOULD BE MOSTLY CLEAR...COOLER AND WINDY AS NICE FROPA
OCCURS. COULD SEE TEMPS NEAR 40 MONDAY NIGHT IN NW AR WITH 40S TO
LOW 50S AREA-WIDE. GRADUAL MODERATION IN TEMPS THROUGH THE EXTENDED
WITH DECREASING DIURNAL RANGES WITH TIME. MODELS HAVE BEEN TOO COOL
LATELY WITH MAX TEMPS...AM LEARY OF KEEPING TEMPS TOO FAR BELOW
CLIMATOLOGICAL NORMS BEYOND MONDAY IN THIS PATTERN.

FCSTID = 26
1ST PERIOD TEMPS AND POPS SUBJECT TO RADICAL CHANGES
TUL   82  63  84  65 /  50  10  20  30
FSM   81  63  85  66 /  50  10  20  20
MLC   84  65  86  68 /  40  10  20  20
BVO   80  60  83  62 /  60  10  20  40
FYV   80  60  82  62 /  60  10  20  30
BYV   80  59  81  61 /  60  10  20  30
MIO   80  60  82  62 /  60  10  20  30
MKO   83  64  85  66 /  50  10  20  30
F10   82  64  84  66 /  50  10  20  30
HHW   85  65  87  69 /  40  10  20  20

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

ARZ001-002-010-011-019-020-029-OKZ049-053>076-181100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
320 AM CDT FRI MAY 18 2001

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED MAINLY SOUTH OF I-40
THROUGH 8AM THIS MORNING...MAINLY IN SOUTHEAST OKLAHOMA.

A COMPLEX OF THUNDERSTORMS OVER CENTRAL OKLAHOMA WILL SPREAD INTO
EASTERN OKLAHOMA BETWEEN 4 AND 6 AM THIS MORNING. THE STORMS ARE
EXPECTED TO SLOWLY WEAKEN AS THEY MOVE EAST WITH THE GREATEST CHANCE
FOR SEVERE STORMS SOUTH OF I-40 IN SOUTHEAST OKLAHOMA. VERY HEAVY
RAIN HAIL AND WIND GUSTS TO 70 MPH WILL BE THE MAIN THREATS. NORTH
OF I-40 ISOLATED STORMS MAY APPROACH SEVERE LIMITS WITH LARGE HAIL
THE MAIN THREAT.

.SPOTTER ACTIVATION...
SPOTTER ACTIVATION MAY BE NEEDED BETWEEN 5AM AND 9AM IN SOUTHEAST
OKLAHOMA.

.DISCUSSION...

THE PRIMARY THREAT FOR SEVERE THUNDERSTORMS THIS MORNING WILL BE
STRONG WINDS ALONG THE LEADING EDGE OF THE COMPLEX. BOWING LINE
SEGMENTS AND WINDS ALONG THE APEX OF THE LARGE SCALE BOW WILL BE THE
PRIMARY THREAT AREAS. THE APEX OF THE BOW LOOKS TO BE HEADED TO THE
EAST SOUTHEAST WHICH WOULD TAKE IT POSSIBLY OVER SOUTHERN PITTSBURG
COUNTY AND INTO CHOCTAW AND PUSHMATAHA COUNTIES AFTER 5AM.

THREAT TABLE
VALID THROUGH 1200 UTC FRIDAY
AREA 1...PITTSBURG...CHOCTAW...PUSHMATAHA COUNTIES
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...95
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...60

THREAT AREAS DEFINE THE GREATEST RISK. PROBABILITIES ARE IN PERCENT.
SIGNIFICANT SEVERE IS DEFINED AS F1 OR GREATER WIND/TORNADO DAMAGE
AND/OR GOLF BALL SIZE HAIL OR LARGER.

.OTHER HAZARDS...
LOCALLY HEAVY RAINS WILL BE POSSIBLE TONIGHT AS SLOW MOVING
THUNDERSTORMS DEVELOP AND ORGANIZE ACROSS THE AREA.

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