Severe Thunderstorm Warning 367, NWS Fort Worth, TX

AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NATIONAL WEATHER SERVICE FORT WORTH TX
612 PM CDT THU AUG 21 2003

.AVIATION DISCUSSION...
VFR. NO CONCERNS.

SHRA AND WEAKENING TSRA TO THE EAST AND SOUTH OF DFW...FTW...DAL...
ASSOCIATED WITH WEAK CONVERGENCE AND NO CAP. TSRA OUTFLOW CURRENTLY
APPROACHING DAL FROM THE EAST IS ENERGIZING THE CUMULUS FIELD OVER
EASTERN DALLAS COUNTY A TOUCH IN MY LATEST VISIBLE SATELLITE IMAGE.
WITH OUTFLOW APPROACHING...CANNOT RULE OUT A VCTS AT DAL. LOW LEVEL
CONVERGENCE APPEARS LIMITED WITH SE WINDS...AND THE OUTFLOW APPEARS
TO BE SLOWING...SO I AM BANKING ON NO TSRA AT DFW/FTW.

ANY ISOLD TSRA IN THE TRACON SHLD DIE OFF BY ARND 02Z WITH LOSS OF
HEATING. WINDS WILL GO LGT OVERNIGHT...WITH LGT EAST WINDS
DEVELOPING WITH MIXING BY 18Z FRI AS A GULF UPPER LOW MOVES INTO
SOUTH TEXAS.

.PUBLIC DISCUSSION...315 PM
IR SATELLITE IMAGERY THIS AFTERNOON HAS BEEN SHOWING AN INCREASE IN
CONVECTIVE ACTIVITY FROM SOUTHEAST MISSOURI...THROUGH ARKANSAS...AND
INTO SOUTHEAST TEXAS. THIS ACTIVITY IS LIKELY DEVELOPING IN AREA OF
SLIGHTLY COOLER MID LEVEL TEMPS/ENHANCED INSTABILITY ASSOCIATED WITH
A WEAK INVERTED MID-LEVEL TROUGH ACROSS MISSISSIPPI. SHORT RANGE
GUIDANCE FROM THE ETA/GFS DOES ADVERTISE SOME PRECIP WORKING INTO
CWFA FROM THE EAST OVERNIGHT...AND WILL ADD POPS TO FORECAST AS A
RESULT. LOW CHANCE POPS WARRANTED IN THE FAR EAST...TAPERED TO
SLIGHT CHANCE ALONG I-35 CORRIDOR...AND DRY IN THE WEST. THIS SEEMS
REASONABLE...GIVEN DEEPER MOISTURE ANALYZED IN MORNING RAOB DATA
ACROSS THE EAST /850 MB DEWPOINTS 13-15 C AND 700 MB DEWPOINTS 3-5
C/. WITH DEEP EASTERLY FLOW AND PROSPECTS OF RAIN INCREASING
OVERNIGHT...WILL LET THE CURRENT HEAT ADVISORY EXPIRE ON SCHEDULE
THIS EVENING.

THROUGH END OF THE WEEKEND...SLIGHT CHANCE/LOW CHANCE POPS APPEAR
WARRANTED FOR MOST PERIODS. UPPER RIDGE WILL BASICALLY RELOCATE TO
THE CENTRAL PLAINS DURING THE FRIDAY-SUNDAY PERIOD...LEAVING NORTH
TEXAS ON SOUTHERN EDGE OF HIGHER MID-LEVEL HEIGHTS. THUS...WILL GO
WITH SLIGHTLY HIGHER POPS/SLIGHTLY COOLER AFTERNOON MAX TEMPS IN
SOUTHERN HALF OF CWFA...AS COOLER MID-LEVEL TEMPS WILL LIKELY
COINCIDE WITH SEABREEZE ACTIVITY ACROSS THIS AREA. ONLY SLIGHT
CHANCE POPS NEEDED FOR THE NORTH...WITH TEMPERATURES REMAINING VERY
WARM. MID-LEVEL WINDS SHOULD REMAIN WEAK THROUGH THE WEEKEND...SO
EXPECT MOST CONVECTION TO BE DIURNALLY DRIVEN...AND ENDING BY LATE
EVENING.

TEMPERATURES ACROSS NORTH TEXAS SHOULD COOL EVEN FURTHER NEXT
WEEK...AS RIDGE OVER THE CENTRAL PLAINS BECOMES SHEARED BY STRONG
JET MOVING ACROSS CANADA. MID-LEVEL HEIGHTS WILL SLOWLY DROP THROUGH
THE WEEK...LEADING TO LOWER/MID 90S BY END OF FORECAST PERIOD. THE
GFS PAINTS A WET PICTURE ACROSS NORTH TEXAS...BUT IS LIKELY
SUFFERING FROM CONVECTIVE FEEDBACK. ONLY SLIGHT POPS WARRANTED...
WITH LACK OF ORGANIZED FORCING.

.FWD...NONE.

65/DD

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-221100-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
450 PM CDT THU AUG 21 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...

ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE POSSIBLE THIS EVENING
ACROSS ALL BUT THE NORTHWEST SECTIONS OF NORTH TEXAS. ANY STORMS
THAT FORM WILL BE CAPABLE OF PRODUCING BRIEF HEAVY RAIN AND
OCCASIONAL CLOUD TO GROUND LIGHTNING.

THERE IS A CHANCE OF THUNDERSTORMS OVERNIGHT ALONG AND EAST OF THE
I-35 CORRIDOR....AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE
EAST. THE MAIN WEATHER THREATS ASSOCIATED WITH ANY STORMS THAT
DEVELOP OVERNIGHT WILL BE CLOUD TO GROUND LIGHTNING...AND BRIEF
HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...

THERE WILL BE AT LEAST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
THROUGH THE PERIOD. AT THIS TIME...THE SEVERE WEATHER THREAT LOOKS
LIMITED DUE TO WEAK WIND SHEAR ALOFT. HOWEVER...AN ISOLATED SEVERE
STORM CAN NOT BE RULED OUT DUE TO MODERATE INSTABILITY OVER THE
REGION.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.