Severe Thunderstorm Warning 327, NWS Fort Worth, TX

AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NATIONAL WEATHER SERVICE FORT WORTH TX
540 PM CDT THU MAY 18 2000

1800Z SOUNDING SHOWS PLENTY OF INSTABILITY AND MOISTURE FOR WHAT
SHOULD AMOUNT TO SEVERAL ROUNDS OF THUNDERSTORMS OVER THE NEXT
SEVERAL DAYS.  THERE WILL BE SOME SEVERE WEATHER POTENTIAL THIS
AFTERNOON AND EVENING...ESPECIALLY WITH ANY STORMS THAT SHOW
STRONG DEVIATE MOTION TO THE SOUTHEAST OR SOUTH.  HEAVY RAIN WILL
ALSO BE A THREAT...MAINLY IN CENTRAL PORTIONS OF NORTH TEXAS
TONIGHT.  IT HAS BEEN RELATIVELY DRY OVER THE PAST 2 AND 1/2 WEEKS...
THUS WE ARE NOT GOING WITH A FLASH FLOOD WATCH FOR TONIGHT...AS
LEAST NOT YET.  IT MAY BE NECESSARY LATER TONIGHT...AND CERTAINLY A
POSSIBILITY FRIDAY.  WILL CALL FOR LOCALLY HEAVY RAIN TONIGHT.

A MODERATELY STRONG UPPER LOW CIRCULATION WILL APPROACH NORTH
TEXAS FROM THE WEST FRIDAY.  WE AGREE WITH THE WASHINGTON PMDSPD
DISCUSSION...THAT THIS SYSTEM WILL BE STRONGER THAN INDICATED BY
THE ETA...PROBABLY MORE LIKE THE AVN FORECAST.  THUS...POPS ARE IN
ORDER FOR MAINLY THE NORTHERN 1/2 OF THE AREA THROUGH THE NEXT
THREE PERIODS.

HAVE GONE WELL ABOVE THE MOS POP FORECAST...BUT WILL FOLLOW RATHER
CLOSE TO MOS TEMPS (WHICH ARE SIMILAR TO FAN GUIDANCE).  CLOUDS AND
COOL AIR NORTH OF THE STATIONARY FRONT WILL KEEP THE HEAT DOWN A
BIT OVER THE NEXT SEVERAL DAYS.  IT IS HARD TO PIN DOWN A RAIN
THREAT IN THE EXTENDED...BUT RESIDUAL MOISTURE COMBINED WITH
MODERATE NORTHWEST FLOW ALOFT WILL FORCE US TO KEEP SLIGHT CHANCES
IN THE FORECAST.

DFW 65/81/65 83 7663    ACT 66/84/66/85 5543

AVIATION...WE'LL BRING THE FRONT QUICKER THROUGH THE D/FW AIRPORTS
(BETWEEN 01Z-02Z)...CONSIDERING THE CURRENT TREND.  STEADY MVFR
CEILINGS/VISIBILITIES SHOULD ALSO EMERGE AFTER 06Z BEHIND THE FRONT
DUE TO DEVELOPING FOG AND LIGHT RAIN OUTSIDE OF CONVECTIVE ACTIVITY.

.FTW...NONE.

...AVIATION DISCUSSION...
THUNDERSTORMS CONTINUE TO TRAIN ALONG NEARLY STATIONARY COLD FRONT
THAT REMAINS NORTHWEST OF METRO AIRPORTS. EXPECT FRONT/STORMS TO
MOVE INTO METRO AREA...WITH A NORTH WIND SHIFT...AROUND 02Z. FRONT
STALLS AROUND OR JUST SOUTH OF METROPLEX SO COULD SEE A PROLONGED
RAIN/THUNDER EVENT TONIGHT INTO MUCH OF THE DAY FRIDAY. 80

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-190200-

HAZARDOUS WEATHER OUTLOOK FOR NORTH TEXAS
NATIONAL WEATHER SERVICE FORT WORTH TX
425 PM CDT THU MAY 18 2000

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON
AND TONIGHT FOR THAT PART OF NORTH TEXAS ALONG AND NORTH OF A
GOLDTHWAITE...WACO...CORSICANA...CANTON LINE.  THIS SLIGHT RISK AREA
INCLUDES GAINESVILLE...SHERMAN...PARIS...MINERAL WELLS...GREENVILLE
...SULPHUR SPRINGS...WACO...AND THE DALLAS FORT WORTH METROPLEX.

AT 425 PM...STRONG TO SEVERE THUNDERSTORMS DEVELOPED ALONG AN
EASTLAND TO GAINESVILLE LINE.  THESE STORMS WERE TAPPING INTO VERY
MOIST AND UNSTABLE AIR.  WITH FAVORABLE WIND SHEAR IN PLACE...THESE
STORMS COULD PRODUCE LARGE HAIL AND DAMAGING WINDS ALONG THEIR
PATH. A FEW OF THESE STORMS COULD GENERATE STRONG ROTATION IN THE
LOWER LEVELS...RESULTING IN ISOLATED TORNADOES.  THE BEST POTENTIAL
FOR TORNADOES WILL BE ALONG THE FRONT BETWEEN WEATHERFORD TO
SHERMAN THIS EVENING...WHERE THE WINDS TURN MORE FAVORABLY WITH
HEIGHT.

HEAVY RAINFALL WILL ALSO OCCUR WITH THIS ACTIVITY.  SINCE THE FRONT
IS EXPECTED TO MOVE SLOWLY SOUTH...STORMS COULD TRACK REPEATEDLY
ACROSS THE SAME AREAS.  AS A RESULT...SOME ISOLATED FLASH FLOODING
MAY OCCUR...ESPECIALLY OVER URBAN AREAS WHERE RAINFALL DOES NOT HAVE
MUCH OF A CHANCE TO SOAK INTO THE GROUND.

EMERGENCY MANAGERS AND STORM SPOTTERS WITHIN THE SLIGHT RISK AREA
SHOULD PREPARE FOR POSSIBLE ACTIVATION TONIGHT.

FOR HAZARDOUS WEATHER/THUNDERSTORM OUTLOOKS FOR ADJACENT AREAS...SEE
OKCSPSOKC (NORTHWESTERN TEXAS...WESTERN AND CENTRAL OKLAHOMA)...
OKCSPSTUL (EASTERN OKLAHOMA AND NORTHWEST ARKANSAS)...NEWS PSSHV
(NORTHEAST TEXAS...NORTHWESTERN LOUISIANA...EXTREME
SOUTHEASTERN OKLAHOMA AND SOUTHWESTERN ARKANSAS)...SATSPSHOU
(SOUTHEAST TEXAS)...SATSPSSAT (SOUTH CENTRAL TEXAS)...AND LBBSPSSJT
(WEST CENTRAL TEXAS).

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