Severe Thunderstorm Warning 294, NWS Fort Worth, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
320 PM CDT FRI MAY 5 2000

DIURNAL HEATING HAS AIDED THE DEVELOPMENT OF A GOOD BAROCLINIC ZONE
OVER SOUTHERN AND WESTERN PORTIONS OF NORTH CENTRAL TEXAS. OUTFLOW
FROM PREVIOUS CONVECTION WILL SERVE AS THE FOCUS FOR A FEW STRONG
THUNDERSTORMS THROUGH THE EVENING HOURS. A SPOKE OF ENERGY EJECTING
FROM THE UPPER LOW OVER WESTERN ARKANSAS HAS ALSO KINDLED STRONG
STORMS OVER SOUTHEASTERN OKLAHOMA. THESE STORMS WILL LIKELY AFFECT
THE RED RIVER VALLEY AND NORTHEAST TEXAS LATER TONIGHT.

THE UPPER LOW IS PROJECTED TO WEAKEN AND LIFT TOWARD THE GREAT LAKES
BY LATE IN THE PERIOD. BELIEVE THERE WILL STILL BE ENOUGH ENERGY
COMBINED WITH A STRONG LOW LEVEL WARM ADVECTION PATTERN TO CONTINUE A
CHANCE OF CONVECTION THROUGH SATURDAY. A CAPPING INVERSION WILL
INCREASE ON SUNDAY...BUT CANT RULE OUT AT LEAST ELEVATED CONVECTION
WITH DIFFERENTIAL HEATING COMPENSATING FOR THE LACK OF UPPER
VERTICAL MOTIONS. BEST CHANCE FOR POPS WILL CONTINUE OVER THE
NORTHEAST CORRIDOR. WILL CONFINE THE MENTION OF SEVERE THUNDERSTORMS
TONIGHT FOR MAINLY SOUTHERN AND NORTHEASTERN PORTIONS INCLUDING
THE EASTERN RED RIVER VALLEY. A FEW MARGINAL STORMS WILL TEASE
POINTS ALONG AND WEST OF A SHERMAN TO DFW LINE.

THE EXTENDED PERIOD CONTINUES TO LOOK A BIT UNSETTLED. AN APPROACHING
UPPER TROF WILL NUDGE A COLD FRONT INTO THE NORTHWEST EARLY IN
THE PERIOD. THESE TWO FEATURES WILL SWING ACROSS NORTH TEXAS
MAINLY ON TUESDAY.

DFW 69/86/69/89 3422                  ACT 70/89/70/91 4322

.FTW...NONE.                                 ...48...

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-052100-

HAZARDOUS WEATHER OUTLOOK FOR NORTH TEXAS
NATIONAL WEATHER SERVICE FORT WORTH TX
1117 AM CDT FRI MAY 5 2000

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR ALL OF NORTH
CENTRAL TEXAS THROUGH EARLY EVENING. THE MAIN THREAT WILL BE
ISOLATED SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS.
THERE IS ALSO THE POTENTIAL FOR BRIEF PERIODS OF HEAVY RAINFALL WHICH
COULD RESULT IN LOCALIZED FLASH FLOODING.

JUST BEFORE MIDDAY...A NEARLY STATIONARY UPPER LEVEL LOW PRESSURE
SYSTEM WAS LOCATED OVER WESTERN ARKANSAS. WEAK DISTURBANCES ROTATING
AROUND THIS STORM WILL ENCOUNTER A DEEPLY MOIST AND UNSTABLE AIRMASS
OVER NORTH TEXAS. AS THUNDERSTORMS FORM AND DISSIPATE...CONVERGING
OUTFLOW BOUNDARIES WILL SERVE AS THE FOCUS FOR ADDITIONAL
THUNDERSTORM DEVELOPMENT.

STEERING WINDS IN THE UPPER ATMOSPHERE REMAIN LIGHT. THIS WILL ALLOW
FOR SLOW MOVING THUNDERSTORMS AND THE TRAINING OF HEAVY RAIN
PRODUCING CELLS OVER THE SAME LOCATION. RAINFALL AMOUNTS OF ONE TO
THREE INCHES ARE POSSIBLE OVER ALREADY SATURATED SOIL CONDITIONS.
THIS MAY LEAD TO HIGH WATER RUNOFF ALONG CREEKS...STREAMS AND A FEW
ROADWAYS. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS
AFTERNOON.

EMERGENCY MANAGEMENT AND STORM SPOTTERS ACROSS ALL OF NORTH CENTRAL
TEXAS SHOULD BE READY FOR LIMITED SPOTTER ACTIVATION THROUGH THIS
AFTERNOON OR EARLY EVENING.

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

48

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-060100-

HAZARDOUS WEATHER OUTLOOK FOR NORTH TEXAS
NATIONAL WEATHER SERVICE FORT WORTH TX
340 PM CDT FRI MAY 5 2000

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS NORTH AND EAST OF A
BONHAM...TO GREENVILLE...TO SULPHUR SPRING LINE...AND SOUTH OF A
GOLDTHWAITE TO PALESTINE LINE THROUGH TONIGHT. THE MAIN THREAT WILL
BE ISOLATED SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS.

A SLOW MOVING UPPER LEVEL LOW...NEAR TULSA LATE THIS AFTERNOON...
WILL CONTINUE TO SPIN UPPER LEVEL DISTURBANCES ACROSS NORTH CENTRAL
TEXAS TONIGHT.  THESE DISTURBANCES WILL MOVE ACROSS MOIST UNSTABLE
AIR AND LEFT OVER BOUNDARIES...RESULTING IN ADDITIONAL SCATTERED TO
NUMEROUS THUNDERSTORMS MOVING OUT OF SOUTHERN OKLAHOMA...AND
TRACKING ACROSS THE RISK AREA COVERING BONHAM...PARIS AND SULPHUR
SPRINGS.  FOR AREAS DOWN SOUTH...SCATTERED STRONG TO SEVERE
THUNDERSTORMS SHOULD BE ON GOING OR DEVELOPING ON OLD OUTFLOW
BOUNDARIES.

EMERGENCY MANAGEMENT AND STORM SPOTTERS ACROSS THE SLIGHT RISK
AREAS OF NORTH CENTRAL TEXAS SHOULD BE READY FOR LIMITED SPOTTER
ACTIVATION THIS EVENING AND OVERNIGHT.

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

75