Flash Flood Warning 62, NWS Fort Worth, TX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1135 AM CDT MON AUG 18 2008

.AVIATION...
MAIN AVIATION WEATHER CONCERNS FOR THE NEXT 24 HOURS WILL BE PERIODS
OF RAIN AND ISOLATED THUNDERSTORMS ALONG WITH MVFR TO OCCASIONAL IFR
CEILINGS AND VISIBILITIES.

THE SHORT WAVE RESPONSIBLE FOR CONVECTION THIS MORNING WILL CONTINUE
TO MOVE EAST THIS AFTERNOON AND SHOULD MOVE INTO EAST TEXAS BY THIS
EVENING.  THERE MAY BE A BRIEF RAIN FREE PERIOD AT ALL TAF SITES
EARLY THIS EVENING.  HOWEVER...LARGE SCALE LIFT WILL INCREASE AGAIN
THROUGH THE EVENING AS THE MAIN UPPER LOW MOVES INTO THE SOUTHWEST
TEXAS PANHANDLE.  WILL CARRY AT LEAST LIGHT RAIN AT ALL SITES
TONIGHT AND TUESDAY MORNING WITH TEMPORARY HEAVY RAIN/ISOLATED THUNDER AND
IFR CEILINGS/VSBY.

AN EAST TO NORTHEAST WIND WILL PREVAIL THROUGH THE TAF PERIOD AT
SPEEDS LESS THAN 10 KNOTS.

.79...
&&

.UPDATE...
930 AM
MAIN CHANGES THIS MORNING INCLUDED RAISING THE TEMPS A BIT AND
CHANGING SOME OF THE WORDING IN ZONES.

77/TLD

&&

.AVIATION...
12Z TAF PACKAGE
MAIN CONCERNS FOR THE NEXT 24 HOURS /AND LIKELY BEYOND/ WILL BE RAIN
AT THE TERMINALS AND CEILINGS. UPPER LEVEL LOW CURRENTLY SLIDING
INTO THE NORTHERN TEXAS PANHANDLE WILL CONTINUE TO MOVE CLOSER TO
NORTH TEXAS OVER THE NEXT 24 HOURS. THIS SYSTEM WILL AID IN A
PROLONGED RAIN EVENT OVER NORTH TEXAS. FOR THE NEXT 24
HOURS...MOST OF THE PRECIPITATION IS EXPECTED TO BE IN THE FORM OF
SHOWERS/RAIN...HOWEVER AN ISOLATED THUNDERSTORM IS POSSIBLE. BRIEF
HEAVY DOWNPOURS WILL ALSO BE POSSIBLE THROUGH THE TAF PERIOD.
EXPECT THE RAIN TO BE INTERMITTENT BUT CONTINUOUS ENOUGH TO PREVAIL
THROUGH THE PERIOD. VFR CIGS ARE IN PLACE RIGHT NOW AT ALL
TERMINALS...BUT MVFR CIGS AND A FEW IFR CIGS ARE BEING REPORTED WEST
OF THE TERMINALS. SOME MVFR CIGS MAY MAKE THEIR WAY INTO THE
AIRPORTS THIS MORNING BUT THEN THE MODELS ARE CONSISTENT IN
LOWERING THE CIGS INTO MVFR AT THE METROPLEX AIRPORTS BY LATE
MORNING AND AT KACT IN THE AFTERNOON. OVERNIGHT...CIGS ARE
EXPECTED TO DROP INTO IFR CONDITIONS AND POTENTIALLY LIFR. CIGS
ARE EXPECTED TO BOUNCE AROUND THIS AFTERNOON BUT GENERALLY REMAIN
IN MVFR DUE TO THE CONTINUOUS RAINFALL. THERE IS A SLIGHT CHANCE
THAT IF THE RAIN DOES NOT AFFECT THE AIRPORTS IN THE AFTERNOON
THEN VFR CIGS MAY OCCUR FOR A FEW HOURS. HOWEVER...CHANCE FOR RAIN
IS HIGH AND CONFIDENCE IS HIGH THAT MVFR CIGS WILL PREVAIL FOR
MOST OF THE AFTERNOON. WINDS WHICH ARE CURRENTLY SOUTHEAST WILL
SHIFT TO THE EAST THIS MORNING. SPEEDS WILL REMAIN AOB 10
KTS...BECOMING ALMOST LIGHT AND VARIABLE THIS AFTERNOON.

82/JLD

&&

.PREV DISCUSSION... /ISSUED 250 AM CDT MON AUG 18 2008/
WET PERIOD EXPECTED THE FIRST HALF OF THE WORK WEEK OVER NORTH
TX...ESPECIALLY THE WRN HALF OF THE REGION TODAY...THEN THE
REMAINDER OF NORTH TX TONIGHT THROUGH TUES NIGHT. UPPER LOW
CURRENTLY OVER THE HIGH PLAINS OF SE CO/NE NM/FAR NORTH TEXAS
PANHANDLE WILL DRIFT SE RIGHT OVER OUR REGION DURING THIS TIME
FRAME. NOW IT WONT BE RAINING ALL THE TIME...BUT MORE OCCASIONAL
AND PERIOD AS MID LVL OCCASIONAL SHORTWAVES ROTATE THROUGH THIS
FEATURE AND ACROSS THE AREA. ATMOSPHERE SHOULD REMAIN MOIST-
ADIABATIC UNTIL LATER TUES...WHEN COLD POOL ALOFT SITUATES OVERHEAD
...INCREASING MID LVL LAPSE RATES SOMEWHAT. BEFORE THEN...BEST
INSTABILITY SHOULD BE OVER THE SOUTH. SO WE WILL HIT ON MORE OF A
LIKELY RAIN EVENT...WITH EMPHASIS ON ISOLATED OR SCATTERED EMBEDDED
THUNDER FROM TIME TO TIME.

MAIN CONCERN WITH THIS SYSTEM WILL BE THE PERIOD HITS OF MODERATE TO
HEAVY RAINFALL...PARTICULARLY OVER THE SRN/WRN PARTS OF THE REGION.
FOR NOW...WE WILL NOT ISSUE ANY FLASH FLOOD WATCHES WITH MUCH
UNCERTAINTY ON THE PLACEMENT/AMOUNTS OF HEAVIER QPF. IT IS HIGHLY
POSSIBLE ONE MAY BE ISSUED LATER TODAY OR TONIGHT FOR PORTIONS OF
NORTH TX...JUST NOT QUITE YET. WITH SUCH A SATURATED ENVIRONMENT...
SEVERE THREAT APPEARS ISOLATED/LOW ATTM.

A PSEUDO...WEAK COLD FRONT WILL BEGIN SLOWLY PUSHING EWD ACROSS THE
REGION BY MID WEEK/WEDNESDAY...AS UPPER LOW LIFTS N/NE AWAY FROM THE
AREA WITH A GRADUAL DECREASING TREND FROM WEST-EAST OF RAIN CHANCES
LATER WED INTO THURS...BEFORE MAINLY A DRY PERIOD OCCURS LATE WEEK
INTO NEXT WEEKEND. WITH CLOUDS/PERIODIC RAINFALL...TEMPS WILL REMAIN
BELOW NORMALS THROUGH MID WEEK...BEFORE RECOVERING BACK INTO THE 90S
DURING THE LATTER EXTENDED PERIOD INTO NEXT WEEKEND.

/05

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  86  70  83  69  85 /  70  80  80  40  40
WACO, TX              86  70  86  69  86 /  70  80  80  60  40
PARIS, TX             88  66  84  65  83 /  50  60  50  50  70
DENTON, TX            85  67  84  65  85 /  70  70  70  40  40
MCKINNEY, TX          86  66  82  66  84 /  60  70  70  40  50
DALLAS, TX            86  70  84  69  84 /  60  70  80  40  50
TERRELL, TX           88  68  84  68  83 /  50  60  70  50  60
CORSICANA, TX         88  69  85  67  85 /  60  70  80  60  50
TEMPLE, TX            86  69  84  67  85 /  70  80  80  60  40

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

77/77

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FORT WORTH TX
350 AM CDT MON AUG 18 2008

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-191100-
MONTAGUE-COOKE-GRAYSON-FANNIN-LAMAR-YOUNG-JACK-WISE-DENTON-COLLIN-
HUNT-DELTA-HOPKINS-STEPHENS-PALO PINTO-PARKER-TARRANT-DALLAS-
ROCKWALL-KAUFMAN-VAN ZANDT-RAINS-EASTLAND-ERATH-HOOD-SOMERVELL-
JOHNSON-ELLIS-HENDERSON-COMANCHE-MILLS-HAMILTON-BOSQUE-HILL-NAVARRO-
FREESTONE-ANDERSON-LAMPASAS-CORYELL-BELL-MCLENNAN-FALLS-LIMESTONE-
LEON-MILAM-ROBERTSON-
350 AM CDT MON AUG 18 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...TODAY AND TONIGHT.
THERE IS A CHANCE FOR THUNDERSTORMS TODAY AND TONIGHT ACROSS ALL
OF NORTH TEXAS. THE BEST CHANCE FOR THUNDERSTORMS WILL BE ACROSS
THE WESTERN THIRD OF NORTH TEXAS. CLOUD TO GROUND LIGHTNING AND
LOCALLY HEAVY RAINFALL WILL BE THE MAIN THREATS. LOCALLY HEAVY
RAINFALL MAY PRODUCE LOCALIZED FLASH FLOODING. ALTHOUGH NO
ORGANIZED SEVERE WEATHER IS EXPECTED...A FEW STORMS MAY BECOME
STRONG AND PRODUCE GUSTY WINDS AND SMALL HAIL.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.
THE CHANCE FOR THUNDERSTORMS CONTINUES ACROSS ALL OF NORTH TEXAS
THROUGH WEDNESDAY NIGHT. ON THURSDAY...THE CHANCE FOR
THUNDERSTORMS WILL BE CONFINED TO THE EASTERN HALF OF NORTH TEXAS.
CLOUD TO GROUND LIGHTNING AND LOCALLY HEAVY RAINFALL WILL BE THE
MAIN THREATS. LOCALLY HEAVY RAINFALL MAY PRODUCE LOCALIZED FLASH
FLOODING. ALTHOUGH NO ORGANIZED SEVERE WEATHER IS EXPECTED...A FEW
STORMS MAY BECOME STRONG PRODUCING GUSTY WINDS AND SMALL HAIL.

THERE IS ALSO A SLIGHT CHANCE FOR THUNDERSTORMS IN THE EASTERN
AND SOUTHEASTERN PORTIONS OF NORTH TEXAS ON FRIDAY AFTERNOON.

.SPOTTER INFORMATION STATEMENT...
VERY LIMITED SPOTTER ACTIVATION MAY BE NEEDED FOR ANY STRONG STORM
THAT MAY APPROACH SEVERE LIMITS.

82/JLD