Severe Thunderstorm Warning 182, NWS Fort Worth, TX

NORTH TEXAS SEVERE WEATHER POTENTIAL STATEMENT
NATIONAL WEATHER SERVICE FT WORTH TX
1130 AM CDT THU MAY 28 1987

THERE IS A HIGH RISK OF SEVERE THUNDERSTORMS OVER THE NORTH TEXAS
GENERALLY WEST OF A PARIS-ATHENS-CENTERVILLE LINE THIS AFTERNOON
AND TONIGHT.  THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER
NORTH TEXAS EAST OF THIS LINE FOR THE SAME PERIOD.

THE UPPER AIR TROUGH THAT HAS LINGERED OVER THE SOUTHWEST US THE PAST
FEW DAYS HAS BEGUN TO SHIFT EASTWARD INTO WEST TEXAS.  THE DYNAMICS
ASSOCIATED WITH THIS SYSTEM WILL NOW INTERFACE WITH THE VERY MOIST
AND UNSTABLE AIR MASS OVER NORTH TEXAS.  THERE ARE IN FACT THREE
DISTINCT SHORT WAVE IMPULSES THAT WILL MOVE THROUGH THE NORTH TEXAS
AREA THIS AFTERNOON THROUGH FRIDAY IN 12 TO 18 HOUR INCREMENTS.
EACH SHOULD TRIGGER INTENSE THUNDERSTORMS.  THE FIRST SHORT WAVE WILL
ENTER THE SOUTHWEST PART OF NORTH TEXAS EARLY THIS AFTERNOON.

TO FURTHER INTENSIFY THE THUNDERSTORM POTENTIAL THIS AFTERNOON IS AN
OUTFLOW BOUNDARY THAT HAS MOVED INTO THE NORTH PART OF THE AREA FROM
LAST NIGHTS THUNDERSTORMS IN OKLAHOMA.  THIS BOUNDARY WAS LOCATED
AT 11030 AM ALONG A TEXARKANA...DALLAS FT WORTH...HASKELL...CHILDRESS
LINE. THE BOUNDARY WILL CONTINUE TO MOVE OUTWARD AT ABOUT 20 MPH.
THIS BOUNDARY IS SIMILAR TO A COLD FRONT...LIFTING AND COOLING THE AIR
IT ENCOUNTERS AS IT MOVES.

THE BEST FOCUS FOR SEVERE THUNDERSTORMS IS WEST OF A
VERNON...HASKELL...LAMPASAS LINE FOR EARLY AFTERNOON. THIS IS WHERE
THE AIR MASS IN THE MOST UNSTABLE...THE OUTFLOW BOUNDARY WILL BE
MOVING THROUGH THE AREA PROVIDING LOW LEVEL LIFT AND THE UPPER AIR
SHORT WAVE WILL BE PROVIDING GOOD UPPER AIR SUPPORT.  THE THREAT OF
SEVERE THUNDERSTORMS WILL SLOWLY SPREAD EASTWARD AS THIS FIRST SHORT
WAVE MOVES NORTHEAST ACROSS THE AREA

ALONG WITH THE THREAT OF TORNADOES...LARGE HAIL..AND DAMAGING WINDS
WILL BE HEAVY RAINS. THE RAIN POTENTIAL OF THREE TO FIVE INCHES IS
VERY LIKELY OVER THE WESTERN 2/3 OF NORTH TEXAS THIS AFTERNOON AND
TONIGHT.  THE BEST LOW LEVEL MOISTURE FOCUS AT THIS TIME
IS A WACO...DALLAS FORT WORTH...SHERMAN LINE.  ALONG AND EITHER SIDE
OF THIS LINE FOR ABOUT 75 MILES IS THE GREATEST THREAT FOR EXTENDED
INTENSE RAIN AND FLOODING.

THIS IS A DANGEROUS WEATHER SITUATION.  EMERGENCY MANAGEMENT OFFICES
THROUGHOUT NORTH TEXAS SHOULD BE PREPARED FOR SEVERE THUNDERSTORMS AND
POSSIBLE FLOODING FOR AT LEAST THE NEXT 36 HOURS.  OUTDOOR EVENTS SUCH
AS GRADUATION EXERCISES DURING THIS PERIOD WILL PROBABLY HAVE TO BE
MOVED INDOORS. STORM SPOTTERS OVER THE WESTERN 2/3 OF NORTH TEXAS
SHOULD EXPECT ACTIVATION AT ANY TIME.  THOSE OVER THE EASTERN 1/3
SHOULD EXPECT ACTIVATION BY EARLY TONIGHT.