Severe Thunderstorm Warning 111, NWS Fort Worth, TX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
500 PM CDT SUN MAY 20 2001

HAVE SENT A QUICK UPDATE TO THE ZONES TO PUT IN SLIGHT POPS IN
SOUTHWESTERN AREAS DUE TO STORM EXPECTED TO MOVE INTO THAT REGION
FROM THE SOUTH.  MAY NEED TO ADD POPS IN NORTHWEST LATER AS WELL. NO
OTHER CHANGES ATTM. 81

.FWD...LAKE WIND CAUTIONS TONIGHT ENTIRE AREA.

81

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-202100-

HAZARDOUS WEATHER OUTLOOK FOR NORTH TEXAS
NATIONAL WEATHER SERVICE FORT WORTH TX
1230 PM CDT SUN MAY 20 2001

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING...GENERALLY ALONG AND NORTH OF A LINE FROM SULPHUR SPRINGS...
TO DENTON...TO MUENSTER. ADJACENT TO THE MODERATE RISK AREA...THERE
IS A SLIGHT RISK OF SEVERE STORMS GENERALLY ALONG AND NORTH OF A LINE
FROM ATHENS...TO WACO...TO LAMPASAS.

CITIES INCLUDED IN THE MODERATE RISK AREA ARE SHERMAN...DENISON...
BONHAM...PARIS...AND COOPER.  CITIES IN THE SLIGHT RISK AREA INCLUDE
GRAHAM...DECATUR...EASTLAND...COMANCHE...STEPHENVILLE...CORSICANA...
AND THE DALLAS...FORT WORTH AREA.

THE MAIN THREAT OF SEVERE WEATHER IN THE MODERATE RISK AREA WILL BE
LARGE HAIL...DAMAGING WIND...AND ISOLATED TORNADOES.  IN THE SLIGHT
RISK AREA...HAIL...HIGH WIND...AND A REDUCED THREAT OF TORNADOES...
WILL BE POSSIBLE.

AN EAST TO WEST BOUNDARY FROM CONVECTION EARLY THIS MORNING ALONG THE
RED RIVER...WILL MOVE NORTH THIS AFTERNOON. SURFACE DEWPOINTS IN THE
LOW 70S WILL FOLLOW THE BOUNDARY INTO OKLAHOMA...HELPING TO PRODUCE A
VERY UNSTABLE AIRMASS. ALONG WITH STRONG SOUTH WIND AT THE SURFACE...
WINDS ALOFT ARE TURNING TO THE WEST AND INCREASING IN SPEED...
CREATING A FAVORABLE WIND SHEAR FOR SEVERE STORMS. FINALLY...AN
APPROACHING UPPER LEVEL DISTURBANCE WILL MOVE INTO THE REGION THIS
AFTERNOON...AROUND THE TIME OF MAXIMUM DAYTIME HEATING.

THE COMBINATION OF STRONG UPWARD MOTIONS ASSOCIATED WITH THE
APPROACHING UPPER LEVEL STORM...VERTICAL WIND SHEAR...AND HIGH
INSTABILITY VALUES...INCREASE THE POSSIBILITY OF SUPERCELL
THUNDERSTORMS...MAINLY IN THE MODERATE RISK AREA.

SCATTERED THUNDERSTORMS WILL LIKELY BEGIN BY MID AFTERNOON ALONG THE
SURFACE BOUNDARY IN OKLAHOMA...OR POSSIBLY NORTHERN PORTIONS OF
TEXAS...THEN TRACK EAST NORTHEAST DURING THE EARLY EVENING. IN
ADDITION...STORMS MAY ALSO DEVELOP ALONG THE DRYLINE DURING THE MID
AFTERNOON HOURS AND SPREAD INTO THE WESTERN PORTIONS OF NORTH TEXAS.

SPOTTER GROUPS AND EMERGENCY MANAGERS WITHIN THE RISK AREAS...
ESPECIALLY IN THE FAR WE+STERN PART OF NORTH TEXAS...AND ALONG THE RED
RIVER...MAY BE ACTIVATED BY MID AFTERNOON.  THE SEVERE THREAT SHOULD
SHIFT NORTHEAST INTO ARKANSAS AND NORTHERN LOUISIANA DURING THE
EVENING.

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-210100-

HAZARDOUS WEATHER OUTLOOK FOR NORTH TEXAS
NATIONAL WEATHER SERVICE FORT WORTH TX
336 PM CDT SUN MAY 20 2001

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON
AND EVENING...ALONG AND NORTH OF A LINE FROM GLEN ROSE...TO
CANTON.

WARM MOIST AIR COMBINED WITH AFTERNOON HEATING AND AN
APPROACHING DRYLINE WILL ENHANCE SCATTERED THUNDERSTORM DEVELOPMENT
ACROSS THE SLIGHT RISK AREA. THE STORMS WILL DEVELOP RAPIDLY AND
SEVERAL COULD BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS
BRIEFLY AFTER FORMING.  THE STORMS WILL MOVE NORTHEAST INTO OKLAHOMA
QUICKLY...AND THOSE REMAINING IN NORTH TEXAS WILL WEAKEN AND DIMINISH
AFTER SUNSET.

SPOTTER GROUPS AND EMERGENCY MANAGERS WITHIN THE RISK AREA MAY BE
ACTIVATED BETWEEN 4 AND 6 PM.

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