000
FXUS64 KFWD 192028
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
328 PM CDT SUN MAY 19 2013
.DISCUSSION...
THE DRYLINE HAS REACHED A LINE FROM WICHITA FALLS TO GRAHAM TO
BROWNWOOD WHERE IT WILL LIKELY STALL BEFORE RETREATING WEST THIS
EVENING. THE MAIN FORECAST CONCERN THROUGH THIS EVENING IS
WHETHER STORMS WILL INITIATE ALONG THE DRYLINE AND THE AMOUNT OF
COVERAGE. AS DISCUSSED IN THE MORNING UPDATE...MOST OF THE MODEL
GUIDANCE IS NOT INITIATING ANY CONVECTION IN OUR REGION THIS
EVENING DESPITE CIN BECOMING ALMOST NEGLIGIBLE ACROSS THE WESTERN
ZONES. HOWEVER THE RUC/HRRR/GFS HAVE NOT WAVERED AND ONE OF THE
HI-RES WRFS AT 12Z HAS NOW JOINED THE INITIATION CAMP. THE ISSUE
AT HAND IS LIKELY THAT TODAY/S STRONG WINDS AND DRY AIR ALOFT WILL
MAKE IT TOUGH FOR AN INFANT UPDRAFT TO BECOME ESTABLISHED AND
GROW INTO A SUPERCELL WITHOUT A SHORTWAVE TO AID IN LIFT. RIGHT
NOW THE BEST GUESS IS THAT 1 TO 3 STORMS WILL MANAGE TO DEVELOP
OVER THE WESTERN CWA BY EARLY EVENING...AND WILL CONTINUE THE
FORECAST OF 20-30 POPS WEST OF A LINE FROM SHERMAN TO DFW TO
LAMPASAS. LOCAL OBJECTIVE ANALYSIS INDICATES CAPE VALUES ARE FROM
2000-3000 J/KG OVER THE CWA AND AMPLE DEEP LAYER SHEAR EXISTS TO
SUPPORT VERY LARGE HAIL AND DAMAGING WINDS. AN ISOLATED TORNADO
WILL BE POSSIBLE BETWEEN 6 AND 8 PM WHEN LOW LEVEL WIND SHEAR
RAMPS UP JUST BEFORE THE SURFACE AIRMASS BECOMES TOO NEGATIVELY
BUOYANT WITH LOSS OF HEATING. STORMS MAY HOLD TOGETHER LONG ENOUGH
TO AFFECT LOCATIONS FARTHER TO THE EAST BY MID-LATE
EVENING...ESPECIALLY NORTH OF I-20...BUT SEVERE WEATHER POTENTIAL
WILL BE DIMINISHING. OTHERWISE A BREEZY AND MUGGY NIGHT IS IN
STORE FOR THE REGION.
THE STORM THREAT FOR MONDAY IS LOOKING GREATER ACROSS A LARGER
PART OF NORTH TEXAS. THE CIN WILL BE EVEN WEAKER THAN TODAY AND
ALMOST ALL OF THE MODELS ARE INDICATING STORM INITIATION IN THE
CWA. THE DRYLINE WILL BE ROUGHLY IN THE SAME LOCATION AS IT IS
TODAY. THE GFS AND NAM ARE MOST AGGRESSIVE WITH HEIGHT FALLS AND
CONVECTION ACROSS THE NW CWA...WHICH RAISES CONFIDENCE THAT THIS
AREA WILL LIKELY SEE SUPERCELL STORMS AND SEVERE WEATHER. EXPECT
SEVERAL SUPERCELLS TO DEVELOP ACROSS THE WESTERN ZONES...INCLUDING
SOME ISOLATED CELLS ACROSS THE SW ZONES. VERY HIGH INSTABILITY
AND AMPLE DEEP LAYER SHEAR WILL SUPPORT A THREAT OF SIGNIFICANT
SEVERE WEATHER INCLUDING GIANT HAIL...DAMAGING WINDS AND A FEW
TORNADOES. LOW LEVEL WIND SHEAR GETS STRONGER AFTER 7PM WITH 0-3KM
SRH VALUES ABOVE 300 M2/S2. SINCE THERE IS LESS CIN THERE IS MORE
TIME FOR EVENING SUPERCELLS TO TAP INTO THIS INSTABILITY AFTER
DARK WHICH IS WHAT IS RAISING OUR CONCERN FOR TORNADOES. HAVE
BUMPED UP POPS TO 30-50 PERCENT IN THE WESTERN ZONES...AND
RAISED THEM FOR THE CENTRAL AND NORTHEAST ZONES AS WELL...AS
SUPERCELLS WILL HEAD EASTWARD AND HOLD TOGETHER LONGER.
ON TUESDAY A WEAK COLD FRONT WILL BECOME DRAPED ACROSS THE CWA
FROM ROUGHLY PARIS TO DFW TO EASTLAND. HIGH TEMPS WILL BE A LITTLE
COOLER THIS DAY...BUT INSTABILITY WILL STILL BE VERY HIGH
ESPECIALLY ACROSS THE SOUTHERN ZONES. ALL MODEL GUIDANCE SHOWS
STRONG UPPER LEVEL FORCING OVER NORTH TEXAS TUESDAY AFTERNOON AS
THE TROUGH AXIS SWINGS THROUGH THE AREA. THIS WILL SET THE STAGE
FOR SCATTERED TO NUMEROUS SHOWERS AND STORMS THAT WILL LIKELY
DEVELOP ALONG THE FRONT TUESDAY AFTERNOON AND MOVE EAST AND
SOUTHEAST INTO THE NIGHTTIME HOURS. SINCE LOW LEVEL WIND FIELDS
RELAX A BIT...THESE STORMS MAY TEND TO ORGANIZE INTO A MCS/SQUALL
LINE OVER THE CENTRAL ZONES. OBVIOUSLY A SEVERE WEATHER THREAT
WILL EXIST WITH THIS CONVECTIVE EPISODE AS WELL. RAINFALL WILL
RANGE FROM A TRACE IN THE NW TO 1.5 INCHES IN THE SOUTHEAST ZONES.
EXPECT THIS CONVECTIVE EPISODE TO FINALLY EXHAUST THE ATMOSPHERE
AND PUSH THE BEST MOISTURE AND INSTABILITY SOUTHEAST OF THE AREA
BY WEDNESDAY MORNING. WILL KEEP WEDNESDAY DRY.
WEAK RIDGING SETS UP OVER THE AREA WEDNESDAY AND INTO NEXT
WEEKEND. SOUTHEAST WINDS WILL CONTINUE WHICH WILL KEEP LOW TEMPS
IN THE MID 60S TO NEAR 70...AND HIGHS IN THE MID 80S TO NEAR 90
EACH DAY. CONVECTION IS EXPECTED TO OCCUR OVER THE HIGH PLAINS
THURSDAY AND FRIDAY...AND WITH A SOUTHEASTERLY FLOW IN THE LOWEST
800MB WE WILL NEED TO KEEP AN EYE ON SOME OF THIS ACTIVITY MAKING
A RUN AT THE CWA DURING THE OVERNIGHT HOURS. SINCE THERE IS A LACK
OF STRONG NORTHWEST FLOW ALOFT IN THE MID LEVELS...BELIEVE
CONVECTION WILL DISSIPATE BEFORE REACHING MOST OF THE AREA...BUT
HAVE INSERTED A SLIGHT CHANCE IN THE NW ZONES THURSDAY AND FRIDAY
NIGHTS. WILL KEEP THE REMAINDER OF THE FORECAST DRY.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 90 71 88 67 / 20 20 40 50 50
WACO, TX 72 90 72 91 68 / 10 10 20 40 60
PARIS, TX 70 87 69 83 65 / 20 10 60 50 50
DENTON, TX 70 89 69 86 64 / 30 30 40 40 40
MCKINNEY, TX 70 89 70 85 65 / 20 20 40 50 50
DALLAS, TX 73 91 73 89 69 / 10 20 40 50 50
TERRELL, TX 70 89 71 87 68 / 10 10 30 50 60
CORSICANA, TX 71 89 72 88 69 / 5 10 20 40 60
TEMPLE, TX 71 90 72 92 69 / 5 10 20 40 60
MINERAL WELLS, TX 70 94 68 88 65 / 20 30 30 40 40
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS64 KFWD 191718 AAC
AFDFWD
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1218 PM CDT SUN MAY 19 2013
.AVIATION...
CONCERNS...WIND GUSTS NEAR OR EXCEEDING 34 KNOTS THIS AFTERNOON.
STRONG AND GUSTY SOUTH WINDS WILL PREVAIL THROUGH THE AFTERNOON
AND AGAIN ON MONDAY. CURRENTLY FEEL THAT MOST GUSTS WILL BE 34
KNOTS OR LESS BUT COULD SEE A FEW AIRPORTS REPORT 35 KNOTS OFF AND
ON DURING THE AFTERNOON. IF THEY GO HIGHER....THEN WE WILL LIKELY
ISSUE AND AWW FOR KDFW. THE WINDS WILL DIMINISH SOMEWHAT FOR THE
EVENING HOURS BUT COULD CRANK UP AND BECOME GUSTY AFTER 06Z AS THE LLJ
STRENGTHENS.
WITH ANOTHER NIGHT OF STRONG SOUTHERLY LLJ...MVFR CIGS SHOULD
RETURN AROUND 10Z AT KACT AND BY 11Z ACROSS THE METROPLEX.
BURN-OFF TIME SHOULD AGAIN BE 16-17Z.
THE DRYLINE OUT WEST IS NOW PUSHING EASTWARD AND WE DO EXPECT SOME
ISOLATED SUPERCELLS TO DEVELOP BY LATE AFTERNOON. HOWEVER...WE
EXPECT THE STORMS TO REMAIN WEST OF ALL TAF SITES THROUGH MID
EVENING HOURS...THEN DIE OFF. 75
&&
.UPDATE...
DRYLINE IS MAKING STEADY PROGRESS TO THE EAST TODAY AS MID LEVEL
WINDS HAVE BECOME MORE WESTERLY ACROSS WEST TEXAS IN THE WAKE OF
THE SHORTWAVE TROUGH THAT MOVED THROUGH THE SOUTHERN PLAINS LAST
NIGHT. ALL MODEL GUIDANCE IS IN AGREEMENT THAT THE DRYLINE WILL
ENTER THE WESTERN CWA THIS AFTERNOON. BECAUSE THE DRYLINE WILL BE
IN THE CWA...THE ONLY CHALLENGE IN THIS FORECAST IS DETERMINING
WHETHER CONVECTIVE INITIATION WILL OCCUR...AND IF IT DOES...THE
EXTENT OF THE COVERAGE. 12Z FWD SOUNDING SHOWS THAT CAPPING HAS
WEAKENED DURING THE LAST 24 HOURS...LIKELY DUE TO LIFT FROM
YESTERDAY/S SHORTWAVE. STRONG SOUTHERLY WINDS WILL KEEP LOW LEVEL
MOIST ADVECTION IN PLACE TODAY AND DEWPOINTS WILL LIKELY HOLD IN
THE 63 TO 66 DEGREE RANGE LATE THIS AFTERNOON TO THE EAST OF THE
DRYLINE. THE THERMODYNAMIC PROFILE LOOKS MORE FAVORABLE FOR SEVERE
CONVECTION IN THE CWA TODAY. HOWEVER MANY MORE MODELS ARE FAILING
TO SHOW CONVECTIVE INITIATION THIS FAR SOUTH TODAY. YESTERDAY
INITIATION WAS VERY LIMITED SOUTH OF THE RED RIVER WHEN THE
GUIDANCE WAS SPLIT ROUGHLY IN HALF BETWEEN ALL CLEAR AND STORMS.
TODAY THAT DROPS TO LESS THAN A FIFTH OF MODELS SHOWING CONVECTIVE
INITIATION.
PART OF THE ISSUE TODAY IS THE LACK OF A SHORTWAVE TO HELP ENHANCE
THE LIFT AT PEAK HEATING. HOWEVER Q-VECTOR CONVERGENCE IS
PRESENT...LIKELY DUE TO THE IMPACTS OF CYCLONIC CURVATURE IN THE
MID-LEVEL HEIGHT FIELDS...WHICH DOES CONTRIBUTE TO VERY SLIGHT
HEIGHT FALLS BETWEEN 18 AND 0Z. WHAT I SUSPECT IS THE MORE LIKELY
ISSUE TODAY ARE THE STRONGER WIND SPEEDS BELOW 700MB WHICH CAUSES
MORE DRY AIR ENTRAINMENT INTO INFANT UPDRAFTS AND TENDS TO CAUSE
TOWERING CUMULUS TO LEAN OVER AND STRUGGLE TO GROW INTO STORMS.
BECAUSE ANY UPDRAFT THAT DOES MANAGE TO OVERCOME THIS IMPEDANCE
WILL LIKELY BECOME A SEVERE SUPERCELL WITH THE POTENTIAL TO
PRODUCE SIGNIFICANT SEVERE WEATHER...WILL ERR ON THE SIDE OF
CAUTION AND KEEP POPS IN THE 20-30 PERCENT RANGE EVEN IF THIS
PROBABILITY IS TECHNICALLY TOO HIGH FOR THIS SITUATION.
THE HRRR/RUC/GFS ARE THE MODELS MOST AGGRESSIVE WITH CONVECTION
THIS AFTERNOON...AND THEY SHOW ACTIVITY AS FAR SOUTH AS SAN
SABA. THUS WILL UPDATE TO STRETCH THE LOW POPS DOWN INTO THE SW
CWA. FURTHERMORE...ANY SUPERCELL STORM THAT DOES GET GOING WILL
HAVE LESS CIN TO COMPETE WITH AS THEY HEAD EAST TODAY...AND WILL
STRETCH THE LOW POPS AND MENTION OF SEVERE WX A COUNTY OR SO
FARTHER EAST. THIS MEANS THE WESTERN PORTIONS OF THE METROPLEX
COULD BE UNDER THE GUN FOR SEVERE WEATHER SHOULD A SUPERCELL
DEVELOP FAR ENOUGH TO THE SOUTH. THE MAIN THREATS TODAY ARE VERY
LARGE HAIL AND DAMAGING WINDS...BUT AN ISOLATED TORNADO WILL BE
POSSIBLE ESPECIALLY BETWEEN 6PM AND 8PM WHEN LOW LEVEL HODOGRAPHS
BEGIN TO ENLARGE JUST BEFORE SURFACE BASED CIN BECOMES TOO HIGH
DUE TO LOSS OF HEATING. TR.92
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT SUN MAY 19 2013/
CONVECTION CONTINUES ACROSS THE PLAINS EARLY THIS MORNING IN THE
ACTIVE REGION OF A BROAD UPPER TROUGH OVER THE WEST-CENTRAL CONUS.
SHOWERS AND THUNDERSTORMS SHOULD REMAIN WELL NORTH OF THE RED
RIVER THIS MORNING BEFORE REDEVELOPING FARTHER SOUTH INTO TEXAS
ONCE AGAIN LATE THIS AFTERNOON. FOR THE SHORT TERM...THE MAIN
CONCERN WOULD BE THE GUSTY SOUTH WINDS TODAY DUE TO A FAIRLY TIGHT
PRESSURE GRADIENT. WINDS MAY GUST AT TIMES TO AT OR ABOVE 30
MPH...BUT AT THIS TIME IT APPEARS THAT CONDITIONS SHOULD REMAIN
BELOW ADVISORY CRITERIA TODAY.
LATER TODAY...STORMS WILL MOST LIKELY INITIATE WEST OF THE REGION
ALONG THE DRYLINE...WHICH IS FORECAST TO ADVANCE EAST TO WITHIN
20-40 MILES OF THE WESTERN-MOST COUNTIES OF THE CWA BY LATE
AFTERNOON. STORM MOTION WOULD BRING ISOLATED ACTIVITY INTO THE
WESTERN AND NORTHWESTERN COUNTIES OF NORTH TEXAS DURING THE LATE
AFTERNOON AND EVENING HOURS BEFORE THE LOSS OF SURFACE HEATING
CAUSES THE STORMS TO DIMINISH TONIGHT. COVERAGE WILL LIKELY REMAIN
SPARSE ONCE AGAIN IN TEXAS WITH HIGHER COVERAGE EXPECTED NORTH OF
THE RED RIVER IN CLOSER PROXIMITY OF THE UPPER TROUGH. WILL GO
WITH 20 POPS THIS EVENING ACROSS ROUGHLY THE NORTHWESTERN HALF OF
THE REGION WITH A SMALL AREA OF 30 POPS NEAR THE RED RIVER. A FEW
STORMS COULD BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS.
INSTABILITY WILL REMAIN SUFFICIENT FOR A FEW SEVERE STORMS OVER
THE NORTHWESTERN COUNTIES AGAIN ON MONDAY. POPS WILL BE SIMILAR ON
MONDAY AS TODAY WITH THE BEST CHANCE OF STORMS GENERALLY NORTH OF
I-20 AND WEST OF I-35.
RAIN CHANCES WILL INCREASE AREA-WIDE TUESDAY THROUGH TUESDAY
NIGHT AS A SHORTWAVE TROUGH SWINGS SOUTHEASTWARD FROM THE GREAT
BASIN INTO THE SOUTHERN PLAINS. SHOWERS AND THUNDERSTORMS MAY BE
ONGOING NORTH OF THE REGION TUESDAY MORNING ALONG A COLD FRONT.
THE FRONT SHOULD REMAIN JUST NORTH OF THE AREA...BUT OUTFLOW FROM
ONGOING ACTIVITY TO THE NORTH...AND THE ADVANCING DRYLINE FROM THE
WEST...SHOULD PROVIDE FOCUS FOR ADDITIONAL DEVELOPMENT DURING THE
AFTERNOON HOURS. THIS ACTIVITY SHOULD SPREAD EAST AND SOUTHEAST
ACROSS NORTH TEXAS TUESDAY EVENING. THE SHORTWAVE WILL CONTINUE TO
PROPAGATE EASTWARD INTO THE SOUTHEASTERN U.S....ALLOWING RAIN
CHANCES TO END FROM NORTHWEST TO SOUTHEAST ON WEDNESDAY. THE
POTENTIAL FOR SEVERE WEATHER WILL REMAIN HIGHEST OVER THE
NORTHWEST COUNTIES...WITH DECREASING POTENTIAL FARTHER SOUTH AND
EAST DUE IN LARGE PART TO TIME OF DAY. THIS SYSTEM WILL BE QUICKLY
REPLACED WITH AN UPPER RIDGE OVER THE CENTRAL AND SOUTHERN PLAINS
LATE IN THE WEEK...WHICH WOULD BRING ABOVE NORMAL TEMPERATURES AND
LOW RAIN CHANCES FOR THE EXTENDED PORTION OF THE FORECAST. 30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 92 72 89 72 89 / 10 20 10 20 40
WACO, TX 92 73 90 73 92 / 5 10 5 10 20
PARIS, TX 89 70 87 70 83 / 10 20 10 40 40
DENTON, TX 92 71 89 70 87 / 10 30 20 30 40
MCKINNEY, TX 91 71 88 71 86 / 10 20 10 30 40
DALLAS, TX 92 74 90 74 91 / 10 10 10 20 40
TERRELL, TX 91 71 89 73 90 / 5 10 10 20 30
CORSICANA, TX 91 72 89 73 91 / 5 5 5 10 20
TEMPLE, TX 91 73 90 73 92 / 5 5 5 10 20
MINERAL WELLS, TX 96 70 92 71 92 / 20 20 20 20 30
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
000
FXUS64 KFWD 191559
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1059 AM CDT SUN MAY 19 2013
.UPDATE...
DRYLINE IS MAKING STEADY PROGRESS TO THE EAST TODAY AS MID LEVEL
WINDS HAVE BECOME MORE WESTERLY ACROSS WEST TEXAS IN THE WAKE OF
THE SHORTWAVE TROUGH THAT MOVED THROUGH THE SOUTHERN PLAINS LAST
NIGHT. ALL MODEL GUIDANCE IS IN AGREEMENT THAT THE DRYLINE WILL
ENTER THE WESTERN CWA THIS AFTERNOON. BECAUSE THE DRYLINE WILL BE
IN THE CWA...THE ONLY CHALLENGE IN THIS FORECAST IS DETERMINING
WHETHER CONVECTIVE INITIATION WILL OCCUR...AND IF IT DOES...THE
EXTENT OF THE COVERAGE. 12Z FWD SOUNDING SHOWS THAT CAPPING HAS
WEAKENED DURING THE LAST 24 HOURS...LIKELY DUE TO LIFT FROM
YESTERDAY/S SHORTWAVE. STRONG SOUTHERLY WINDS WILL KEEP LOW LEVEL
MOIST ADVECTION IN PLACE TODAY AND DEWPOINTS WILL LIKELY HOLD IN
THE 63 TO 66 DEGREE RANGE LATE THIS AFTERNOON TO THE EAST OF THE
DRYLINE. THE THERMODYNAMIC PROFILE LOOKS MORE FAVORABLE FOR SEVERE
CONVECTION IN THE CWA TODAY. HOWEVER MANY MORE MODELS ARE FAILING
TO SHOW CONVECTIVE INITIATION THIS FAR SOUTH TODAY. YESTERDAY
INITIATION WAS VERY LIMITED SOUTH OF THE RED RIVER WHEN THE
GUIDANCE WAS SPLIT ROUGHLY IN HALF BETWEEN ALL CLEAR AND STORMS.
TODAY THAT DROPS TO LESS THAN A FIFTH OF MODELS SHOWING CONVECTIVE
INITIATION.
PART OF THE ISSUE TODAY IS THE LACK OF A SHORTWAVE TO HELP ENHANCE
THE LIFT AT PEAK HEATING. HOWEVER Q-VECTOR CONVERGENCE IS
PRESENT...LIKELY DUE TO THE IMPACTS OF CYCLONIC CURVATURE IN THE
MID-LEVEL HEIGHT FIELDS...WHICH DOES CONTRIBUTE TO VERY SLIGHT
HEIGHT FALLS BETWEEN 18 AND 0Z. WHAT I SUSPECT IS THE MORE LIKELY
ISSUE TODAY ARE THE STRONGER WIND SPEEDS BELOW 700MB WHICH CAUSES
MORE DRY AIR ENTRAINMENT INTO INFANT UPDRAFTS AND TENDS TO CAUSE
TOWERING CUMULUS TO LEAN OVER AND STRUGGLE TO GROW INTO STORMS.
BECAUSE ANY UPDRAFT THAT DOES MANAGE TO OVERCOME THIS IMPEDANCE
WILL LIKELY BECOME A SEVERE SUPERCELL WITH THE POTENTIAL TO
PRODUCE SIGNIFICANT SEVERE WEATHER...WILL ERR ON THE SIDE OF
CAUTION AND KEEP POPS IN THE 20-30 PERCENT RANGE EVEN IF THIS
PROBABILITY IS TECHNICALLY TOO HIGH FOR THIS SITUATION.
THE HRRR/RUC/GFS ARE THE MODELS MOST AGGRESSIVE WITH CONVECTION
THIS AFTERNOON...AND THEY SHOW ACTIVITY AS FAR SOUTH AS SAN
SABA. THUS WILL UPDATE TO STRETCH THE LOW POPS DOWN INTO THE SW
CWA. FURTHERMORE...ANY SUPERCELL STORM THAT DOES GET GOING WILL
HAVE LESS CIN TO COMPETE WITH AS THEY HEAD EAST TODAY...AND WILL
STRETCH THE LOW POPS AND MENTION OF SEVERE WX A COUNTY OR SO
FARTHER EAST. THIS MEANS THE WESTERN PORTIONS OF THE METROPLEX
COULD BE UNDER THE GUN FOR SEVERE WEATHER SHOULD A SUPERCELL
DEVELOP FAR ENOUGH TO THE SOUTH. THE MAIN THREATS TODAY ARE VERY
LARGE HAIL AND DAMAGING WINDS...BUT AN ISOLATED TORNADO WILL BE
POSSIBLE ESPECIALLY BETWEEN 6PM AND 8PM WHEN LOW LEVEL HODOGRAPHS
BEGIN TO ENLARGE JUST BEFORE SURFACE BASED CIN BECOMES TOO HIGH
DUE TO LOSS OF HEATING.
TR.92
&&
.AVIATION...
/12Z TAFS/
CONCERNS...STRATUS...GUSTY WINDS...CONVECTION NORTHWEST.
A FINGER OF STRATUS HAS MADE ITS WAY UP THE I-35 CORRIDOR...RIDING
A 50-KT LLJ. THE LAYER IS RATHER THIN...AND WITH THE VIGOROUS
WINDS FRAGMENTING THE STRATUS...HAVE CHOSEN TO CARRY TEMPO GROUPS
AT ALL SITES. AS THESE WINDS MIX TO THE SURFACE MID TO LATE
MORNING...SOME GUSTS MAY EXCEED 35KTS. EXPECT THIS WILL BE SHORT-
LIVED ALTHOUGH THE GUSTY WINDS WILL PERSIST THE REMAINDER OF THE
DAY.
ANY LATE AFTERNOON CONVECTION WILL AGAIN DEVELOP WELL
WEST/NORTHWEST OF METROPLEX TAF SITES. THE STEERING FLOW WILL HAVE
MORE OF A WESTERLY COMPONENT...WHICH MAY ALLOW STORMS TO POSE
GREATER IMPACTS TO NORTHWEST ARRIVALS DURING THE EARLY EVENING.
GENERALLY PERSISTENCE FORECAST FOR SUNDAY NIGHT AND MONDAY WITH
NOCTURNAL STRATUS AND AFTERNOON CONVECTION NORTHWEST. STRATUS MAY
ARRIVE A BIT EARLIER MONDAY MORNING.
25
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT SUN MAY 19 2013/
CONVECTION CONTINUES ACROSS THE PLAINS EARLY THIS MORNING IN THE
ACTIVE REGION OF A BROAD UPPER TROUGH OVER THE WEST-CENTRAL CONUS.
SHOWERS AND THUNDERSTORMS SHOULD REMAIN WELL NORTH OF THE RED
RIVER THIS MORNING BEFORE REDEVELOPING FARTHER SOUTH INTO TEXAS
ONCE AGAIN LATE THIS AFTERNOON. FOR THE SHORT TERM...THE MAIN
CONCERN WOULD BE THE GUSTY SOUTH WINDS TODAY DUE TO A FAIRLY TIGHT
PRESSURE GRADIENT. WINDS MAY GUST AT TIMES TO AT OR ABOVE 30
MPH...BUT AT THIS TIME IT APPEARS THAT CONDITIONS SHOULD REMAIN
BELOW ADVISORY CRITERIA TODAY.
LATER TODAY...STORMS WILL MOST LIKELY INITIATE WEST OF THE REGION
ALONG THE DRYLINE...WHICH IS FORECAST TO ADVANCE EAST TO WITHIN
20-40 MILES OF THE WESTERN-MOST COUNTIES OF THE CWA BY LATE
AFTERNOON. STORM MOTION WOULD BRING ISOLATED ACTIVITY INTO THE
WESTERN AND NORTHWESTERN COUNTIES OF NORTH TEXAS DURING THE LATE
AFTERNOON AND EVENING HOURS BEFORE THE LOSS OF SURFACE HEATING
CAUSES THE STORMS TO DIMINISH TONIGHT. COVERAGE WILL LIKELY REMAIN
SPARSE ONCE AGAIN IN TEXAS WITH HIGHER COVERAGE EXPECTED NORTH OF
THE RED RIVER IN CLOSER PROXIMITY OF THE UPPER TROUGH. WILL GO
WITH 20 POPS THIS EVENING ACROSS ROUGHLY THE NORTHWESTERN HALF OF
THE REGION WITH A SMALL AREA OF 30 POPS NEAR THE RED RIVER. A FEW
STORMS COULD BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS.
INSTABILITY WILL REMAIN SUFFICIENT FOR A FEW SEVERE STORMS OVER
THE NORTHWESTERN COUNTIES AGAIN ON MONDAY. POPS WILL BE SIMILAR ON
MONDAY AS TODAY WITH THE BEST CHANCE OF STORMS GENERALLY NORTH OF
I-20 AND WEST OF I-35.
RAIN CHANCES WILL INCREASE AREA-WIDE TUESDAY THROUGH TUESDAY
NIGHT AS A SHORTWAVE TROUGH SWINGS SOUTHEASTWARD FROM THE GREAT
BASIN INTO THE SOUTHERN PLAINS. SHOWERS AND THUNDERSTORMS MAY BE
ONGOING NORTH OF THE REGION TUESDAY MORNING ALONG A COLD FRONT.
THE FRONT SHOULD REMAIN JUST NORTH OF THE AREA...BUT OUTFLOW FROM
ONGOING ACTIVITY TO THE NORTH...AND THE ADVANCING DRYLINE FROM THE
WEST...SHOULD PROVIDE FOCUS FOR ADDITIONAL DEVELOPMENT DURING THE
AFTERNOON HOURS. THIS ACTIVITY SHOULD SPREAD EAST AND SOUTHEAST
ACROSS NORTH TEXAS TUESDAY EVENING. THE SHORTWAVE WILL CONTINUE TO
PROPAGATE EASTWARD INTO THE SOUTHEASTERN U.S....ALLOWING RAIN
CHANCES TO END FROM NORTHWEST TO SOUTHEAST ON WEDNESDAY. THE
POTENTIAL FOR SEVERE WEATHER WILL REMAIN HIGHEST OVER THE
NORTHWEST COUNTIES...WITH DECREASING POTENTIAL FARTHER SOUTH AND
EAST DUE IN LARGE PART TO TIME OF DAY. THIS SYSTEM WILL BE QUICKLY
REPLACED WITH AN UPPER RIDGE OVER THE CENTRAL AND SOUTHERN PLAINS
LATE IN THE WEEK...WHICH WOULD BRING ABOVE NORMAL TEMPERATURES AND
LOW RAIN CHANCES FOR THE EXTENDED PORTION OF THE FORECAST.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 92 72 89 72 89 / 10 20 10 20 40
WACO, TX 92 73 90 73 92 / 5 10 5 10 20
PARIS, TX 89 70 87 70 83 / 10 20 10 40 40
DENTON, TX 92 71 89 70 87 / 10 30 20 30 40
MCKINNEY, TX 91 71 88 71 86 / 10 20 10 30 40
DALLAS, TX 92 74 90 74 91 / 10 10 10 20 40
TERRELL, TX 91 71 89 73 90 / 5 10 10 20 30
CORSICANA, TX 91 72 89 73 91 / 5 5 5 10 20
TEMPLE, TX 91 73 90 73 92 / 5 5 5 10 20
MINERAL WELLS, TX 96 70 92 71 92 / 20 20 20 20 30
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
000
FXUS64 KFWD 191210 AAA
AFDFWD
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
710 AM CDT SUN MAY 19 2013
.AVIATION...
/12Z TAFS/
CONCERNS...STRATUS...GUSTY WINDS...CONVECTION NORTHWEST.
A FINGER OF STRATUS HAS MADE ITS WAY UP THE I-35 CORRIDOR...RIDING
A 50-KT LLJ. THE LAYER IS RATHER THIN...AND WITH THE VIGOROUS
WINDS FRAGMENTING THE STRATUS...HAVE CHOSEN TO CARRY TEMPO GROUPS
AT ALL SITES. AS THESE WINDS MIX TO THE SURFACE MID TO LATE
MORNING...SOME GUSTS MAY EXCEED 35KTS. EXPECT THIS WILL BE SHORT-
LIVED ALTHOUGH THE GUSTY WINDS WILL PERSIST THE REMAINDER OF THE
DAY.
ANY LATE AFTERNOON CONVECTION WILL AGAIN DEVELOP WELL
WEST/NORTHWEST OF METROPLEX TAF SITES. THE STEERING FLOW WILL HAVE
MORE OF A WESTERLY COMPONENT...WHICH MAY ALLOW STORMS TO POSE
GREATER IMPACTS TO NORTHWEST ARRIVALS DURING THE EARLY EVENING.
GENERALLY PERSISTENCE FORECAST FOR SUNDAY NIGHT AND MONDAY WITH
NOCTURNAL STRATUS AND AFTERNOON CONVECTION NORTHWEST. STRATUS MAY
ARRIVE A BIT EARLIER MONDAY MORNING.
25
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT SUN MAY 19 2013/
CONVECTION CONTINUES ACROSS THE PLAINS EARLY THIS MORNING IN THE
ACTIVE REGION OF A BROAD UPPER TROUGH OVER THE WEST-CENTRAL CONUS.
SHOWERS AND THUNDERSTORMS SHOULD REMAIN WELL NORTH OF THE RED
RIVER THIS MORNING BEFORE REDEVELOPING FARTHER SOUTH INTO TEXAS
ONCE AGAIN LATE THIS AFTERNOON. FOR THE SHORT TERM...THE MAIN
CONCERN WOULD BE THE GUSTY SOUTH WINDS TODAY DUE TO A FAIRLY TIGHT
PRESSURE GRADIENT. WINDS MAY GUST AT TIMES TO AT OR ABOVE 30
MPH...BUT AT THIS TIME IT APPEARS THAT CONDITIONS SHOULD REMAIN
BELOW ADVISORY CRITERIA TODAY.
LATER TODAY...STORMS WILL MOST LIKELY INITIATE WEST OF THE REGION
ALONG THE DRYLINE...WHICH IS FORECAST TO ADVANCE EAST TO WITHIN
20-40 MILES OF THE WESTERN-MOST COUNTIES OF THE CWA BY LATE
AFTERNOON. STORM MOTION WOULD BRING ISOLATED ACTIVITY INTO THE
WESTERN AND NORTHWESTERN COUNTIES OF NORTH TEXAS DURING THE LATE
AFTERNOON AND EVENING HOURS BEFORE THE LOSS OF SURFACE HEATING
CAUSES THE STORMS TO DIMINISH TONIGHT. COVERAGE WILL LIKELY REMAIN
SPARSE ONCE AGAIN IN TEXAS WITH HIGHER COVERAGE EXPECTED NORTH OF
THE RED RIVER IN CLOSER PROXIMITY OF THE UPPER TROUGH. WILL GO
WITH 20 POPS THIS EVENING ACROSS ROUGHLY THE NORTHWESTERN HALF OF
THE REGION WITH A SMALL AREA OF 30 POPS NEAR THE RED RIVER. A FEW
STORMS COULD BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS.
INSTABILITY WILL REMAIN SUFFICIENT FOR A FEW SEVERE STORMS OVER
THE NORTHWESTERN COUNTIES AGAIN ON MONDAY. POPS WILL BE SIMILAR ON
MONDAY AS TODAY WITH THE BEST CHANCE OF STORMS GENERALLY NORTH OF
I-20 AND WEST OF I-35.
RAIN CHANCES WILL INCREASE AREA-WIDE TUESDAY THROUGH TUESDAY
NIGHT AS A SHORTWAVE TROUGH SWINGS SOUTHEASTWARD FROM THE GREAT
BASIN INTO THE SOUTHERN PLAINS. SHOWERS AND THUNDERSTORMS MAY BE
ONGOING NORTH OF THE REGION TUESDAY MORNING ALONG A COLD FRONT.
THE FRONT SHOULD REMAIN JUST NORTH OF THE AREA...BUT OUTFLOW FROM
ONGOING ACTIVITY TO THE NORTH...AND THE ADVANCING DRYLINE FROM THE
WEST...SHOULD PROVIDE FOCUS FOR ADDITIONAL DEVELOPMENT DURING THE
AFTERNOON HOURS. THIS ACTIVITY SHOULD SPREAD EAST AND SOUTHEAST
ACROSS NORTH TEXAS TUESDAY EVENING. THE SHORTWAVE WILL CONTINUE TO
PROPAGATE EASTWARD INTO THE SOUTHEASTERN U.S....ALLOWING RAIN
CHANCES TO END FROM NORTHWEST TO SOUTHEAST ON WEDNESDAY. THE
POTENTIAL FOR SEVERE WEATHER WILL REMAIN HIGHEST OVER THE
NORTHWEST COUNTIES...WITH DECREASING POTENTIAL FARTHER SOUTH AND
EAST DUE IN LARGE PART TO TIME OF DAY. THIS SYSTEM WILL BE QUICKLY
REPLACED WITH AN UPPER RIDGE OVER THE CENTRAL AND SOUTHERN PLAINS
LATE IN THE WEEK...WHICH WOULD BRING ABOVE NORMAL TEMPERATURES AND
LOW RAIN CHANCES FOR THE EXTENDED PORTION OF THE FORECAST.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 92 72 89 72 89 / 10 20 10 20 40
WACO, TX 92 73 90 73 92 / 5 10 5 10 20
PARIS, TX 89 70 87 70 83 / 10 20 10 40 40
DENTON, TX 92 71 89 70 87 / 10 30 20 30 40
MCKINNEY, TX 91 71 88 71 86 / 10 20 10 30 40
DALLAS, TX 92 74 90 74 91 / 10 20 10 20 40
TERRELL, TX 91 71 89 73 90 / 5 20 10 20 30
CORSICANA, TX 91 72 89 73 91 / 5 10 5 10 20
TEMPLE, TX 91 73 90 73 92 / 5 10 5 10 20
MINERAL WELLS, TX 95 70 92 71 92 / 20 20 20 20 30
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/30
000
FXUS64 KFWD 190836
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
336 AM CDT SUN MAY 19 2013
.DISCUSSION...
CONVECTION CONTINUES ACROSS THE PLAINS EARLY THIS MORNING IN THE
ACTIVE REGION OF A BROAD UPPER TROUGH OVER THE WEST-CENTRAL CONUS.
SHOWERS AND THUNDERSTORMS SHOULD REMAIN WELL NORTH OF THE RED
RIVER THIS MORNING BEFORE REDEVELOPING FARTHER SOUTH INTO TEXAS
ONCE AGAIN LATE THIS AFTERNOON. FOR THE SHORT TERM...THE MAIN
CONCERN WOULD BE THE GUSTY SOUTH WINDS TODAY DUE TO A FAIRLY TIGHT
PRESSURE GRADIENT. WINDS MAY GUST AT TIMES TO AT OR ABOVE 30
MPH...BUT AT THIS TIME IT APPEARS THAT CONDITIONS SHOULD REMAIN
BELOW ADVISORY CRITERIA TODAY.
LATER TODAY...STORMS WILL MOST LIKELY INITIATE WEST OF THE REGION
ALONG THE DRYLINE...WHICH IS FORECAST TO ADVANCE EAST TO WITHIN
20-40 MILES OF THE WESTERN-MOST COUNTIES OF THE CWA BY LATE
AFTERNOON. STORM MOTION WOULD BRING ISOLATED ACTIVITY INTO THE
WESTERN AND NORTHWESTERN COUNTIES OF NORTH TEXAS DURING THE LATE
AFTERNOON AND EVENING HOURS BEFORE THE LOSS OF SURFACE HEATING
CAUSES THE STORMS TO DIMINISH TONIGHT. COVERAGE WILL LIKELY REMAIN
SPARSE ONCE AGAIN IN TEXAS WITH HIGHER COVERAGE EXPECTED NORTH OF
THE RED RIVER IN CLOSER PROXIMITY OF THE UPPER TROUGH. WILL GO
WITH 20 POPS THIS EVENING ACROSS ROUGHLY THE NORTHWESTERN HALF OF
THE REGION WITH A SMALL AREA OF 30 POPS NEAR THE RED RIVER. A FEW
STORMS COULD BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS.
INSTABILITY WILL REMAIN SUFFICIENT FOR A FEW SEVERE STORMS OVER
THE NORTHWESTERN COUNTIES AGAIN ON MONDAY. POPS WILL BE SIMILAR ON
MONDAY AS TODAY WITH THE BEST CHANCE OF STORMS GENERALLY NORTH OF
I-20 AND WEST OF I-35.
RAIN CHANCES WILL INCREASE AREA-WIDE TUESDAY THROUGH TUESDAY
NIGHT AS A SHORTWAVE TROUGH SWINGS SOUTHEASTWARD FROM THE GREAT
BASIN INTO THE SOUTHERN PLAINS. SHOWERS AND THUNDERSTORMS MAY BE
ONGOING NORTH OF THE REGION TUESDAY MORNING ALONG A COLD FRONT.
THE FRONT SHOULD REMAIN JUST NORTH OF THE AREA...BUT OUTFLOW FROM
ONGOING ACTIVITY TO THE NORTH...AND THE ADVANCING DRYLINE FROM THE
WEST...SHOULD PROVIDE FOCUS FOR ADDITIONAL DEVELOPMENT DURING THE
AFTERNOON HOURS. THIS ACTIVITY SHOULD SPREAD EAST AND SOUTHEAST
ACROSS NORTH TEXAS TUESDAY EVENING. THE SHORTWAVE WILL CONTINUE TO
PROPAGATE EASTWARD INTO THE SOUTHEASTERN U.S....ALLOWING RAIN
CHANCES TO END FROM NORTHWEST TO SOUTHEAST ON WEDNESDAY. THE
POTENTIAL FOR SEVERE WEATHER WILL REMAIN HIGHEST OVER THE
NORTHWEST COUNTIES...WITH DECREASING POTENTIAL FARTHER SOUTH AND
EAST DUE IN LARGE PART TO TIME OF DAY. THIS SYSTEM WILL BE QUICKLY
REPLACED WITH AN UPPER RIDGE OVER THE CENTRAL AND SOUTHERN PLAINS
LATE IN THE WEEK...WHICH WOULD BRING ABOVE NORMAL TEMPERATURES AND
LOW RAIN CHANCES FOR THE EXTENDED PORTION OF THE FORECAST.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 92 72 89 72 89 / 10 20 10 20 40
WACO, TX 92 73 90 73 92 / 5 10 5 10 20
PARIS, TX 89 70 87 70 83 / 10 20 10 40 40
DENTON, TX 92 71 89 70 87 / 10 30 20 30 40
MCKINNEY, TX 91 71 88 71 86 / 10 20 10 30 40
DALLAS, TX 92 74 90 74 91 / 10 20 10 20 40
TERRELL, TX 91 71 89 73 90 / 5 20 10 20 30
CORSICANA, TX 91 72 89 73 91 / 5 10 5 10 20
TEMPLE, TX 91 73 90 73 92 / 5 10 5 10 20
MINERAL WELLS, TX 95 70 92 71 92 / 20 20 20 20 30
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/30
000
FXUS64 KFWD 190458
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1158 PM CDT SAT MAY 18 2013
.AVIATION...
FOR THE 06Z TAFS...TIMING THE ONSET OF MVFR CIGS AND ANY IMPACTS
FROM THUNDERSTORM ACTIVITY DURING THE FORECAST PERIOD ARE THE
PRIMARY FORECAST CONCERNS.
THE MOST SIGNIFICANT CHANGE MADE FROM THE 00Z TAFS WAS TO REMOVE
THE POTENTIAL FOR HEAT BURSTS FROM THE TAFS FOR THE OVERNIGHT
HOURS. ANVIL PRECIPITATION REMAINS NORTH OF THE RED RIVER
TONIGHT...AND THE LACK OF THUNDERSTORM ACTIVITY TO THE SOUTHWEST
INDICATES THAT ANVILS ARE UNLIKELY TO MOVE OVER AREA TAFS TONIGHT.
WE REMAIN IN AN IDEAL ENVIRONMENT FOR HEAT BURSTS WITH VERY STEEP
MID LEVEL LAPSE RATES AND DRY AIR ALOFT. WILL CONTINUE TO WATCH
FOR ELEVATED LIGHT RAIN TONIGHT AS THIS COULD RESULT IN HEAT BURSTS
NEAR AREA AIRPORTS...HOWEVER THIS SEEMS UNLIKELY AT THIS TIME.
MVFR CIGS...LEFT MVFR STRATUS IN AFTER 12Z AT METROPLEX AREA
TAFS...AND A COUPLE HOURS EARLIER FOR WACO. A STRONG LOW LEVEL JET
OF 50 TO 55 KTS WAS IN PLACE OVER NORTH TX...AND EXPECT THAT THIS
WILL RESULT IN SOME HIGH MVFR CIGS BUILDING OVER AREA TAF SITES AS
THIS JET PERSISTS THROUGH SUNRISE. STRATUS SHOULD BE SHALLOW IN
NATURE AND QUICK TO SCATTER OUT AFTER A FEW HOURS OF HEATING WITH
VERY DRY AIR IN PLACE ABOVE THE LOW LEVEL JET.
THUNDERSTORMS TOMORROW...TOMORROW LOOKS TO BE ANOTHER DAY OF
PRIMARILY DRYLINE THUNDERSTORM ACTIVITY NEAR AREA AIRPORTS. THE
DRYLINE WILL BE CLOSER TO OUR TAF SITES TOMORROW...HOWEVER A CAP
IS EXPECTED TO REMAIN FIRMLY IN PLACE OVER THE REGION SO DO NOT
EXPECT ANY ACTIVITY THAT FIRES LONG THE DRYLINE TO DIRECTLY IMPACT
AREA AIRPORTS. CAN NOT RULE OUT THE POTENTIAL FOR HEAT BURSTS FROM
ANVIL PRECIPITATION AGAIN TOMORROW EVENING...HOWEVER CONFIDENCE IS
TOO LOW TO MENTION ANYTHING IN THE TAFS AT THIS TIME.
CAVANAUGH
&&
.UPDATE...
EVENING UPDATE WILL REMOVE MENTION OF ISOLATED THUNDERSTORMS FOR
THE REMAINDER OF THE NIGHT. ENVIRONMENT ACROSS NORTH TEXAS HAS
CONSIDERABLE CONDITIONAL INSTABILITY HOWEVER IT WILL REMAIN CAPPED
TO DEEP CONVECTION. WHAT APPEARED TO BE MORE FAVORABLE EARLIER WAS
THE THREAT FOR DOWNBURST WINDS OR HEATBURSTS FROM CONVECTION TO
THE WEST. WITH ABUNDANT DRY AIR IN THE MID LEVELS AND AMPLE ANVIL
DEBRIS SPREADING EASTWARD...A FAVORABLE SETUP FOR THE PHENOMENON
WAS IN PLACE. LACK OF SUBSTANTIAL DEEP CONVECTION TO THE WEST OF
OUR AREA HOWEVER HAS FOR ALL INTENTS AND PURPOSES SQUASHED THIS
SCENARIO. WARM AND BREEZY CONDITIONS EXPECTED OVERNIGHT WITH MOST
THUNDERSTORM ACTIVITY REMAINING WELL TO THE NORTH OF OUR AREA.
ONLY CHANGE TO CURRENT FORECAST WAS TO REMOVE MENTION OF
THUNDERSTORMS.
DUNN
&&
.PREV DISCUSSION... /ISSUED 324 PM CDT SAT MAY 18 2013/
A SLOW MOVING UPPER LEVEL TROUGH OVER THE PLAINS WILL PUT THE
REGION IN AN ACTIVE WEATHER PATTERN THROUGH TUESDAY WITH SEVERE
WEATHER POSSIBLE EACH DAY. PRIMARILY THE NORTHWEST/NORTHERN PARTS
OF THE CWA WILL BE IMPACTED BY CONVECTION TONIGHT THROUGH
MONDAY...BUT THE CENTRAL AND SOUTHERN CWA WILL BE UNDER THE GUN
FOR A WIDESPREAD RAIN EVENT TUESDAY AFTERNOON AND EVENING. THE
MAIN CHANGE WITH THIS FORECAST CONCERNS TONIGHT...AND THE ADDITION
OF POPS FOR AREAS NORTH OF I-20...NOT NECESSARILY FOR SUPERCELL
TYPE CONVECTION...BUT FOR VERY HIGH BASED WEAK CONVECTION THAT
COULD CAUSE STRONG GUSTY WINDS VIA HEATBURSTS LATE THIS EVENING.
THIS AFTERNOON THE DRY LINE REMAINS WELL TO THE WEST OF THE REGION
AND SHORT-TERM GUIDANCE SUGGESTS IT WILL STAY AS FAR WEST AS A
CHILDRESS TO SAN ANGELO LINE. THIS RESULTS IN SOME CONCERNS ABOUT
WHETHER SURFACE BASED CONVECTION WILL INITIATE CLOSE ENOUGH TO
ENTER THE CWA. MID LEVEL WESTERLY FLOW IS STRONGER TODAY...AND
THEREFORE STORM MOTIONS WOULD BE MORE EASTERLY. SURFACE BASED
CONVECTION WOULD HAVE ENOUGH SHEAR AND INSTABILITY TO BECOME
SUPERCELLS AND PRODUCE SIGNIFICANT SEVERE WEATHER. LOCAL OBJECTIVE
ANALYSIS INDICATES THE BEST AXIS OF INSTABILITY AND DIMINISHED CIN
IS TO THE WEST OF THE CWA...WITH THE AIRMASS OVER OUR WESTERN
COUNTIES NOT QUITE AS UNSTABLE WITH CAPE AT 1500-2500 J/KG AND
HIGHER CIN DUE TO DEWPOINTS DROPPING INTO THE LOW 60S. WATER VAPOR
LOOP AND MODEL GUIDANCE DOES INDICATE A SHORTWAVE IS APPROACHING
FROM THE SOUTHWEST AND THE LIFT PROVIDED BY THIS FEATURE SHOULD
ALLOW SURFACE BASED CONVECTION TO INITIATE AND ORGANIZE WEST OF
THE CWA. SOME OF THIS ACTIVITY SHOULD ENTER THE NW ZONES...BUT
BELIEVE THE CELLS MAY WEAKEN A BIT AND BECOME ELEVATED DUE TO THE
SLIGHTLY LESS FAVORABLE ENVIRONMENT. IN SUMMARY...A SEVERE THREAT
EXIST FOR PRIMARILY HAIL/WIND...AND POPS ARE NEAR 20-30 PERCENT IN
THE NW ZONES EARLY THIS EVENING. THE RISK FOR GIANT HAIL OR
TORNADOES DOES NOT LOOK AS HIGH AS IT DID YESTERDAY IN OUR CWA.
CURRENTLY...WEAK ELEVATED CONVECTION BASED AT AROUND 14000FT
CONTINUES TO BUBBLE UP OVER THE WESTERN ZONES. MOST OF THE PRECIP
IS EVAPORATING BEFORE REACHING THE GROUND...BUT THIS ELEVATED
MOISTURE PLUME LOOKS LIKE IT WILL HAVE IMPLICATIONS ON THE FORECAST
OVER THE NORTHERN HALF OF THE AREA TONIGHT. ESSENTIALLY THERE ARE
A FEW MODELS NOW INDICATING A MOISTURE PLUME FROM 500-600MB
ENTERING THE NORTHERN HALF OF THE AREA...LIKELY ASSOCIATED WITH
ANVILS FROM STORMS TO THE WEST. THE ISSUE IS THAT THIS MOISTURE
WILL BE WITHIN AN AREA OF DRY ADIABATIC LAPSE RATES...AND
COINCIDES WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. THE STAGE
IS SET FOR SCATTERED ELEVATED CONVECTION WITH BASES ABOVE 12000FT.
MOST OF THE RAIN WILL EVAPORATE DUE TO VERY DRY AIR BELOW 600MB...
BUT SPORADIC LIGHTNING STRIKES WILL BE POSSIBLE TONIGHT.
MEANWHILE...A 50KT SOUTHERLY LOW LEVEL JET WILL BE DEVELOPING AND
THE ENVIRONMENT WILL BE FAVORABLE FOR THIS HIGH BASED CONVECTION
TO TRANSFER STRONG WINDS TO THE SURFACE IN WHAT IS TECHNICALLY A
TYPE OF HEATBURST. THIS IS TOUGH TO COMMUNICATE TO THE PUBLIC IN
SIMPLE TERMS...BUT THE POPS ARE FOR MEASURABLE RAIN AND THE CHANCE
FOR THAT IS LOW. HOWEVER GUSTY WINDS AND LIGHT RAIN MAY AFFECT A
LARGE PORTION OF THE NORTHERN CWA TONIGHT...AND THEREFORE HAVE
BUMPED UP SOUTH WINDS TO 20-25 MPH AND MENTIONED GUSTS TO 40 MPH
IN THE ZONES. THIS FORECAST IS NOT OF HIGH CONFIDENCE...PARTLY
BECAUSE IT MAY BE THE FIRST NWS FORECAST THAT HAS EVER TRIED TO
INCLUDE A RISK OF HEATBURSTS IN A ZONE FORECAST. HOWEVER LOOKING
AT ALL OF THE DATA...THE SETUP TONIGHT LOOKS VERY FAVORABLE FOR
PERIOD OF GUSTY SOUTH WINDS BENEATH ELEVATED RADAR ECHOES. WE
SHALL SEE.
A STRONG SHORTWAVE TROUGH WILL ROTATE THROUGH THE SOUTHERN PLAINS
TOMORROW AND WILL PUSH THE DRYLINE FARTHER TO THE EAST INTO THE NW
ZONES. WITH DAYTIME HEATING...CIN SHOULD BE LOW ENOUGH OVER THE NW
ZONES FOR ISOLATED SEVERE STORMS TO DEVELOP IN THE AFTERNOON.
WIND FIELDS WILL STRENGTHEN A BIT AND SUPERCELL STORM MOTION WILL
BE EASTERLY. WEST TO EAST STORM TRACKS ON SUNDAY EVENING MEANS
POPS WILL COVER THE AREAS NORTH OF I-20. LOW LEVEL HELICITY RAMPS
UP AROUND SUNSET SUNDAY EVENING AND IF SUPERCELLS CAN OVERCOME THE
WEAK CIN AND TAP INTO SURFACE PARCELS...A TORNADO THREAT WILL
EXIST. MONDAY LOOKS LIKE A CARBON COPY OF SUNDAY/S PATTERN WITH
THE MAIN FEATURES IN THE SAME PLACE...JUST A LITTLE WEAKER CIN SO
POPS ARE SLIGHTLY HIGHER/FARTHER SOUTH. TEMPS WILL REMAIN NEAR
PERSISTENCE AND WINDS WILL BE BREEZY SUNDAY AND MONDAY.
ON TUESDAY THE UPPER TROUGH WILL BEGIN TO FINALLY MOVE EAST AND
THIS WILL PUSH A COLD FRONT INTO THE NW ZONES TUESDAY AFTERNOON.
SCATTERED TO NUMEROUS STORMS SHOULD FIRE ALONG THE COLD FRONT
TUESDAY AFTERNOON AND WORK EAST AND SOUTHEAST ACROSS MUCH OF THE
AREA INTO TUESDAY NIGHT. RAINFALL MAY BE WIDESPREAD AND AVERAGE
1/2 TO 1 INCH. SEVERE WEATHER WILL BE A CONCERN GIVEN HIGH
INSTABILITY AND ADEQUATE DEEP LAYER SHEAR.
THE FRONT WILL PUSH THROUGH THE REGION AND DRIER AIR WILL END RAIN
CHANCES FROM NORTH TO SOUTH WEDNESDAY. LOW TEMPS WILL COOL A BIT
AND INTO THE 60S DUE TO THE LOWER DEWPOINTS...BUT HIGHS WILL
CONTINUE IN THE MID 80S TO NEAR 90 THROUGH THE REMAINDER OF THE
WEEK. WILL KEEP THE FORECAST DRY AS AN UPPER RIDGE SETTLES INTO
THE AREA...BUT WE MAY HAVE TO WATCH FOR NW FLOW MCS ACTIVITY ON
FRIDAY NIGHT IN THE NW ZONES. TOO FAR OUT TO RELY ON THE MODEL
FORECASTS FOR THIS POSSIBILITY AT THIS TIME.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 90 72 89 72 / 5 10 20 10 20
WACO, TX 72 90 73 90 73 / 5 5 5 5 10
PARIS, TX 70 88 70 87 70 / 10 10 20 10 40
DENTON, TX 73 90 71 89 70 / 10 10 20 20 30
MCKINNEY, TX 73 89 71 88 71 / 10 10 20 10 30
DALLAS, TX 75 91 74 90 74 / 5 10 20 10 20
TERRELL, TX 72 88 71 89 73 / 5 5 20 10 20
CORSICANA, TX 71 89 72 89 73 / 5 5 5 5 10
TEMPLE, TX 71 89 73 90 73 / 5 5 5 5 10
MINERAL WELLS, TX 71 93 70 92 71 / 5 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
000
FXUS64 KFWD 190316 AAB
AFDFWD
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1016 PM CDT SAT MAY 18 2013
.UPDATE...
EVENING UPDATE WILL REMOVE MENTION OF ISOLATED THUNDERSTORMS FOR
THE REMAINDER OF THE NIGHT. ENVIRONMENT ACROSS NORTH TEXAS HAS
CONSIDERABLE CONDITIONAL INSTABILITY HOWEVER IT WILL REMAIN CAPPED
TO DEEP CONVECTION. WHAT APPEARED TO BE MORE FAVORABLE EARLIER WAS
THE THREAT FOR DOWNBURST WINDS OR HEATBURSTS FROM CONVECTION TO
THE WEST. WITH ABUNDANT DRY AIR IN THE MID LEVELS AND AMPLE ANVIL
DEBRIS SPREADING EASTWARD...A FAVORABLE SETUP FOR THE PHENOMENON
WAS IN PLACE. LACK OF SUBSTANTIAL DEEP CONVECTION TO THE WEST OF
OUR AREA HOWEVER HAS FOR ALL INTENTS AND PURPOSES SQUASHED THIS
SCENARIO. WARM AND BREEZY CONDITIONS EXPECTED OVERNIGHT WITH MOST
THUNDERSTORM ACTIVITY REMAINING WELL TO THE NORTH OF OUR AREA.
ONLY CHANGE TO CURRENT FORECAST WAS TO REMOVE MENTION OF
THUNDERSTORMS.
DUNN
&&
.AVIATION...
FOR THE 00Z TAFS...TIMING THE ONSET OF STRATUS...AND THE IMPACT OF
ANY ANVIL CLOUD PRECIPITATION OVER METROPLEX AREA TAF SITES ARE
THE PRIMARY FORECAST CONCERNS.
REGARDING STRATUS...KEPT MVFR STRATUS IN THE FORECAST FOR A FEW
HOURS TOMORROW MORNING AS MOST GUIDANCE AGREES THAT A 50 KT LOW
LEVEL JET WILL RAMP UP OVER NORTH TX TONIGHT. THIS STRONG JET WILL
HELP KEEP GULF MOISTURE IN PLACE...BUT THERE IS UNCERTAINTY
REGARDING THE PRESENCE OF STRATUS WITHIN THE LOW LEVEL JET. THE
LOW LEVEL JET IS NOT EXPECTED TO BE ASSOCIATED WITH STRONG WARM
AIR ADVECTION OVERNIGHT...THEREFORE THERE WILL ONLY BE SHALLOW
LIFT WITHIN THE CORE OF THE JET OVER NORTH TX. THIS SHALLOW LIFT
MAY BE SUFFICIENT FOR STRATUS TO FORM...BUT THERE IS NO GUARANTEE
THAT THIS WILL PAN OUT. THE LAMP IS AGGRESSIVE WITH THE STRATUS AS
IT HAS BEEN RECENTLY. THE RAP FORECAST SOUNDINGS DO NOT SUPPORT
THE DEVELOPMENT OF STRATUS WHILE THE NAM DOES. AT THIS POINT JUST
KEPT THE STRATUS IN THE FORECAST BUT BUMPED UP THE CIGS TO 2500 FT
WHICH SHOULD HAVE LITTLE IMPACT ON AIRPORT OPERATIONS EVEN IF IT
IS IN PLACE.
REGARDING ANVIL CLOUD PRECIPITATION TONIGHT...PLACED A MENTION OF
LIGHT RAIN WITH GUSTY WINDS IN THE FORECAST FROM 06 TO 09Z FOR
METROPLEX AREA TAF SITES. THIS WILL ONLY OCCUR IF STORMS BECOME
ESTABLISHED AROUND ABILENE THIS EVENING. AT THE TIME OF THIS
DISCUSSION VISIBLE SATELLITE AND REGIONAL RADAR SHOWED SOME GOOD
CONVECTIVE ATTEMPTS JUST NORTH OF ABILENE...AND THIS TIPPED THE
SCALE TOWARDS INCLUDING THE LIGHT ANVIL PRECIPITATION IN METROPLEX
AREA TAFS. ANY LIGHT RAIN IN THE EXTREMELY UNSTABLE AIR MASS IN
PLACE OVER NORTH TX WILL RESULT IN HEAT BURSTS...OR HEAT BURST LIKE
ACTIVITY. ESSENTIALLY VERY GUSTY WINDS ACCOMPANIED BY A WARMING
AND DRYING OUT OF THE NEAR SURFACE AIR. IF THE ABILENE ACTIVITY
NEVER BECOMES ESTABLISHED...WILL REMOVE THIS GROUP FROM THE TAFS
IN FUTURE AMENDMENTS.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 324 PM CDT SAT MAY 18 2013/
A SLOW MOVING UPPER LEVEL TROUGH OVER THE PLAINS WILL PUT THE
REGION IN AN ACTIVE WEATHER PATTERN THROUGH TUESDAY WITH SEVERE
WEATHER POSSIBLE EACH DAY. PRIMARILY THE NORTHWEST/NORTHERN PARTS
OF THE CWA WILL BE IMPACTED BY CONVECTION TONIGHT THROUGH
MONDAY...BUT THE CENTRAL AND SOUTHERN CWA WILL BE UNDER THE GUN
FOR A WIDESPREAD RAIN EVENT TUESDAY AFTERNOON AND EVENING. THE
MAIN CHANGE WITH THIS FORECAST CONCERNS TONIGHT...AND THE ADDITION
OF POPS FOR AREAS NORTH OF I-20...NOT NECESSARILY FOR SUPERCELL
TYPE CONVECTION...BUT FOR VERY HIGH BASED WEAK CONVECTION THAT
COULD CAUSE STRONG GUSTY WINDS VIA HEATBURSTS LATE THIS EVENING.
THIS AFTERNOON THE DRY LINE REMAINS WELL TO THE WEST OF THE REGION
AND SHORT-TERM GUIDANCE SUGGESTS IT WILL STAY AS FAR WEST AS A
CHILDRESS TO SAN ANGELO LINE. THIS RESULTS IN SOME CONCERNS ABOUT
WHETHER SURFACE BASED CONVECTION WILL INITIATE CLOSE ENOUGH TO
ENTER THE CWA. MID LEVEL WESTERLY FLOW IS STRONGER TODAY...AND
THEREFORE STORM MOTIONS WOULD BE MORE EASTERLY. SURFACE BASED
CONVECTION WOULD HAVE ENOUGH SHEAR AND INSTABILITY TO BECOME
SUPERCELLS AND PRODUCE SIGNIFICANT SEVERE WEATHER. LOCAL OBJECTIVE
ANALYSIS INDICATES THE BEST AXIS OF INSTABILITY AND DIMINISHED CIN
IS TO THE WEST OF THE CWA...WITH THE AIRMASS OVER OUR WESTERN
COUNTIES NOT QUITE AS UNSTABLE WITH CAPE AT 1500-2500 J/KG AND
HIGHER CIN DUE TO DEWPOINTS DROPPING INTO THE LOW 60S. WATER VAPOR
LOOP AND MODEL GUIDANCE DOES INDICATE A SHORTWAVE IS APPROACHING
FROM THE SOUTHWEST AND THE LIFT PROVIDED BY THIS FEATURE SHOULD
ALLOW SURFACE BASED CONVECTION TO INITIATE AND ORGANIZE WEST OF
THE CWA. SOME OF THIS ACTIVITY SHOULD ENTER THE NW ZONES...BUT
BELIEVE THE CELLS MAY WEAKEN A BIT AND BECOME ELEVATED DUE TO THE
SLIGHTLY LESS FAVORABLE ENVIRONMENT. IN SUMMARY...A SEVERE THREAT
EXIST FOR PRIMARILY HAIL/WIND...AND POPS ARE NEAR 20-30 PERCENT IN
THE NW ZONES EARLY THIS EVENING. THE RISK FOR GIANT HAIL OR
TORNADOES DOES NOT LOOK AS HIGH AS IT DID YESTERDAY IN OUR CWA.
CURRENTLY...WEAK ELEVATED CONVECTION BASED AT AROUND 14000FT
CONTINUES TO BUBBLE UP OVER THE WESTERN ZONES. MOST OF THE PRECIP
IS EVAPORATING BEFORE REACHING THE GROUND...BUT THIS ELEVATED
MOISTURE PLUME LOOKS LIKE IT WILL HAVE IMPLICATIONS ON THE FORECAST
OVER THE NORTHERN HALF OF THE AREA TONIGHT. ESSENTIALLY THERE ARE
A FEW MODELS NOW INDICATING A MOISTURE PLUME FROM 500-600MB
ENTERING THE NORTHERN HALF OF THE AREA...LIKELY ASSOCIATED WITH
ANVILS FROM STORMS TO THE WEST. THE ISSUE IS THAT THIS MOISTURE
WILL BE WITHIN AN AREA OF DRY ADIABATIC LAPSE RATES...AND
COINCIDES WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. THE STAGE
IS SET FOR SCATTERED ELEVATED CONVECTION WITH BASES ABOVE 12000FT.
MOST OF THE RAIN WILL EVAPORATE DUE TO VERY DRY AIR BELOW 600MB...
BUT SPORADIC LIGHTNING STRIKES WILL BE POSSIBLE TONIGHT.
MEANWHILE...A 50KT SOUTHERLY LOW LEVEL JET WILL BE DEVELOPING AND
THE ENVIRONMENT WILL BE FAVORABLE FOR THIS HIGH BASED CONVECTION
TO TRANSFER STRONG WINDS TO THE SURFACE IN WHAT IS TECHNICALLY A
TYPE OF HEATBURST. THIS IS TOUGH TO COMMUNICATE TO THE PUBLIC IN
SIMPLE TERMS...BUT THE POPS ARE FOR MEASURABLE RAIN AND THE CHANCE
FOR THAT IS LOW. HOWEVER GUSTY WINDS AND LIGHT RAIN MAY AFFECT A
LARGE PORTION OF THE NORTHERN CWA TONIGHT...AND THEREFORE HAVE
BUMPED UP SOUTH WINDS TO 20-25 MPH AND MENTIONED GUSTS TO 40 MPH
IN THE ZONES. THIS FORECAST IS NOT OF HIGH CONFIDENCE...PARTLY
BECAUSE IT MAY BE THE FIRST NWS FORECAST THAT HAS EVER TRIED TO
INCLUDE A RISK OF HEATBURSTS IN A ZONE FORECAST. HOWEVER LOOKING
AT ALL OF THE DATA...THE SETUP TONIGHT LOOKS VERY FAVORABLE FOR
PERIOD OF GUSTY SOUTH WINDS BENEATH ELEVATED RADAR ECHOES. WE
SHALL SEE.
A STRONG SHORTWAVE TROUGH WILL ROTATE THROUGH THE SOUTHERN PLAINS
TOMORROW AND WILL PUSH THE DRYLINE FARTHER TO THE EAST INTO THE NW
ZONES. WITH DAYTIME HEATING...CIN SHOULD BE LOW ENOUGH OVER THE NW
ZONES FOR ISOLATED SEVERE STORMS TO DEVELOP IN THE AFTERNOON.
WIND FIELDS WILL STRENGTHEN A BIT AND SUPERCELL STORM MOTION WILL
BE EASTERLY. WEST TO EAST STORM TRACKS ON SUNDAY EVENING MEANS
POPS WILL COVER THE AREAS NORTH OF I-20. LOW LEVEL HELICITY RAMPS
UP AROUND SUNSET SUNDAY EVENING AND IF SUPERCELLS CAN OVERCOME THE
WEAK CIN AND TAP INTO SURFACE PARCELS...A TORNADO THREAT WILL
EXIST. MONDAY LOOKS LIKE A CARBON COPY OF SUNDAY/S PATTERN WITH
THE MAIN FEATURES IN THE SAME PLACE...JUST A LITTLE WEAKER CIN SO
POPS ARE SLIGHTLY HIGHER/FARTHER SOUTH. TEMPS WILL REMAIN NEAR
PERSISTENCE AND WINDS WILL BE BREEZY SUNDAY AND MONDAY.
ON TUESDAY THE UPPER TROUGH WILL BEGIN TO FINALLY MOVE EAST AND
THIS WILL PUSH A COLD FRONT INTO THE NW ZONES TUESDAY AFTERNOON.
SCATTERED TO NUMEROUS STORMS SHOULD FIRE ALONG THE COLD FRONT
TUESDAY AFTERNOON AND WORK EAST AND SOUTHEAST ACROSS MUCH OF THE
AREA INTO TUESDAY NIGHT. RAINFALL MAY BE WIDESPREAD AND AVERAGE
1/2 TO 1 INCH. SEVERE WEATHER WILL BE A CONCERN GIVEN HIGH
INSTABILITY AND ADEQUATE DEEP LAYER SHEAR.
THE FRONT WILL PUSH THROUGH THE REGION AND DRIER AIR WILL END RAIN
CHANCES FROM NORTH TO SOUTH WEDNESDAY. LOW TEMPS WILL COOL A BIT
AND INTO THE 60S DUE TO THE LOWER DEWPOINTS...BUT HIGHS WILL
CONTINUE IN THE MID 80S TO NEAR 90 THROUGH THE REMAINDER OF THE
WEEK. WILL KEEP THE FORECAST DRY AS AN UPPER RIDGE SETTLES INTO
THE AREA...BUT WE MAY HAVE TO WATCH FOR NW FLOW MCS ACTIVITY ON
FRIDAY NIGHT IN THE NW ZONES. TOO FAR OUT TO RELY ON THE MODEL
FORECASTS FOR THIS POSSIBILITY AT THIS TIME.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 90 72 89 72 / 5 10 20 10 20
WACO, TX 72 90 73 90 73 / 5 5 5 5 10
PARIS, TX 70 88 70 87 70 / 10 10 20 10 40
DENTON, TX 73 90 71 89 70 / 10 10 20 20 30
MCKINNEY, TX 73 89 71 88 71 / 10 10 20 10 30
DALLAS, TX 75 91 74 90 74 / 5 10 20 10 20
TERRELL, TX 72 88 71 89 73 / 5 5 20 10 20
CORSICANA, TX 71 89 72 89 73 / 5 5 5 5 10
TEMPLE, TX 71 89 73 90 73 / 5 5 5 5 10
MINERAL WELLS, TX 71 93 70 92 71 / 5 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS64 KFWD 190005
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
705 PM CDT SAT MAY 18 2013
.AVIATION...
FOR THE 00Z TAFS...TIMING THE ONSET OF STRATUS...AND THE IMPACT OF
ANY ANVIL CLOUD PRECIPITATION OVER METROPLEX AREA TAF SITES ARE
THE PRIMARY FORECAST CONCERNS.
REGARDING STRATUS...KEPT MVFR STRATUS IN THE FORECAST FOR A FEW
HOURS TOMORROW MORNING AS MOST GUIDANCE AGREES THAT A 50 KT LOW
LEVEL JET WILL RAMP UP OVER NORTH TX TONIGHT. THIS STRONG JET WILL
HELP KEEP GULF MOISTURE IN PLACE...BUT THERE IS UNCERTAINTY
REGARDING THE PRESENCE OF STRATUS WITHIN THE LOW LEVEL JET. THE
LOW LEVEL JET IS NOT EXPECTED TO BE ASSOCIATED WITH STRONG WARM
AIR ADVECTION OVERNIGHT...THEREFORE THERE WILL ONLY BE SHALLOW
LIFT WITHIN THE CORE OF THE JET OVER NORTH TX. THIS SHALLOW LIFT
MAY BE SUFFICIENT FOR STRATUS TO FORM...BUT THERE IS NO GUARANTEE
THAT THIS WILL PAN OUT. THE LAMP IS AGGRESSIVE WITH THE STRATUS AS
IT HAS BEEN RECENTLY. THE RAP FORECAST SOUNDINGS DO NOT SUPPORT
THE DEVELOPMENT OF STRATUS WHILE THE NAM DOES. AT THIS POINT JUST
KEPT THE STRATUS IN THE FORECAST BUT BUMPED UP THE CIGS TO 2500 FT
WHICH SHOULD HAVE LITTLE IMPACT ON AIRPORT OPERATIONS EVEN IF IT
IS IN PLACE.
REGARDING ANVIL CLOUD PRECIPITATION TONIGHT...PLACED A MENTION OF
LIGHT RAIN WITH GUSTY WINDS IN THE FORECAST FROM 06 TO 09Z FOR
METROPLEX AREA TAF SITES. THIS WILL ONLY OCCUR IF STORMS BECOME
ESTABLISHED AROUND ABILENE THIS EVENING. AT THE TIME OF THIS
DISCUSSION VISIBLE SATELLITE AND REGIONAL RADAR SHOWED SOME GOOD
CONVECTIVE ATTEMPTS JUST NORTH OF ABILENE...AND THIS TIPPED THE
SCALE TOWARDS INCLUDING THE LIGHT ANVIL PRECIPITATION IN METROPLEX
AREA TAFS. ANY LIGHT RAIN IN THE EXTREMELY UNSTABLE AIR MASS IN
PLACE OVER NORTH TX WILL RESULT IN HEAT BURSTS...OR HEAT BURST LIKE
ACTIVITY. ESSENTIALLY VERY GUSTY WINDS ACCOMPANIED BY A WARMING
AND DRYING OUT OF THE NEAR SURFACE AIR. IF THE ABILENE ACTIVITY
NEVER BECOMES ESTABLISHED...WILL REMOVE THIS GROUP FROM THE TAFS
IN FUTURE AMENDMENTS.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 324 PM CDT SAT MAY 18 2013/
A SLOW MOVING UPPER LEVEL TROUGH OVER THE PLAINS WILL PUT THE
REGION IN AN ACTIVE WEATHER PATTERN THROUGH TUESDAY WITH SEVERE
WEATHER POSSIBLE EACH DAY. PRIMARILY THE NORTHWEST/NORTHERN PARTS
OF THE CWA WILL BE IMPACTED BY CONVECTION TONIGHT THROUGH
MONDAY...BUT THE CENTRAL AND SOUTHERN CWA WILL BE UNDER THE GUN
FOR A WIDESPREAD RAIN EVENT TUESDAY AFTERNOON AND EVENING. THE
MAIN CHANGE WITH THIS FORECAST CONCERNS TONIGHT...AND THE ADDITION
OF POPS FOR AREAS NORTH OF I-20...NOT NECESSARILY FOR SUPERCELL
TYPE CONVECTION...BUT FOR VERY HIGH BASED WEAK CONVECTION THAT
COULD CAUSE STRONG GUSTY WINDS VIA HEATBURSTS LATE THIS EVENING.
THIS AFTERNOON THE DRY LINE REMAINS WELL TO THE WEST OF THE REGION
AND SHORT-TERM GUIDANCE SUGGESTS IT WILL STAY AS FAR WEST AS A
CHILDRESS TO SAN ANGELO LINE. THIS RESULTS IN SOME CONCERNS ABOUT
WHETHER SURFACE BASED CONVECTION WILL INITIATE CLOSE ENOUGH TO
ENTER THE CWA. MID LEVEL WESTERLY FLOW IS STRONGER TODAY...AND
THEREFORE STORM MOTIONS WOULD BE MORE EASTERLY. SURFACE BASED
CONVECTION WOULD HAVE ENOUGH SHEAR AND INSTABILITY TO BECOME
SUPERCELLS AND PRODUCE SIGNIFICANT SEVERE WEATHER. LOCAL OBJECTIVE
ANALYSIS INDICATES THE BEST AXIS OF INSTABILITY AND DIMINISHED CIN
IS TO THE WEST OF THE CWA...WITH THE AIRMASS OVER OUR WESTERN
COUNTIES NOT QUITE AS UNSTABLE WITH CAPE AT 1500-2500 J/KG AND
HIGHER CIN DUE TO DEWPOINTS DROPPING INTO THE LOW 60S. WATER VAPOR
LOOP AND MODEL GUIDANCE DOES INDICATE A SHORTWAVE IS APPROACHING
FROM THE SOUTHWEST AND THE LIFT PROVIDED BY THIS FEATURE SHOULD
ALLOW SURFACE BASED CONVECTION TO INITIATE AND ORGANIZE WEST OF
THE CWA. SOME OF THIS ACTIVITY SHOULD ENTER THE NW ZONES...BUT
BELIEVE THE CELLS MAY WEAKEN A BIT AND BECOME ELEVATED DUE TO THE
SLIGHTLY LESS FAVORABLE ENVIRONMENT. IN SUMMARY...A SEVERE THREAT
EXIST FOR PRIMARILY HAIL/WIND...AND POPS ARE NEAR 20-30 PERCENT IN
THE NW ZONES EARLY THIS EVENING. THE RISK FOR GIANT HAIL OR
TORNADOES DOES NOT LOOK AS HIGH AS IT DID YESTERDAY IN OUR CWA.
CURRENTLY...WEAK ELEVATED CONVECTION BASED AT AROUND 14000FT
CONTINUES TO BUBBLE UP OVER THE WESTERN ZONES. MOST OF THE PRECIP
IS EVAPORATING BEFORE REACHING THE GROUND...BUT THIS ELEVATED
MOISTURE PLUME LOOKS LIKE IT WILL HAVE IMPLICATIONS ON THE FORECAST
OVER THE NORTHERN HALF OF THE AREA TONIGHT. ESSENTIALLY THERE ARE
A FEW MODELS NOW INDICATING A MOISTURE PLUME FROM 500-600MB
ENTERING THE NORTHERN HALF OF THE AREA...LIKELY ASSOCIATED WITH
ANVILS FROM STORMS TO THE WEST. THE ISSUE IS THAT THIS MOISTURE
WILL BE WITHIN AN AREA OF DRY ADIABATIC LAPSE RATES...AND
COINCIDES WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. THE STAGE
IS SET FOR SCATTERED ELEVATED CONVECTION WITH BASES ABOVE 12000FT.
MOST OF THE RAIN WILL EVAPORATE DUE TO VERY DRY AIR BELOW 600MB...
BUT SPORADIC LIGHTNING STRIKES WILL BE POSSIBLE TONIGHT.
MEANWHILE...A 50KT SOUTHERLY LOW LEVEL JET WILL BE DEVELOPING AND
THE ENVIRONMENT WILL BE FAVORABLE FOR THIS HIGH BASED CONVECTION
TO TRANSFER STRONG WINDS TO THE SURFACE IN WHAT IS TECHNICALLY A
TYPE OF HEATBURST. THIS IS TOUGH TO COMMUNICATE TO THE PUBLIC IN
SIMPLE TERMS...BUT THE POPS ARE FOR MEASURABLE RAIN AND THE CHANCE
FOR THAT IS LOW. HOWEVER GUSTY WINDS AND LIGHT RAIN MAY AFFECT A
LARGE PORTION OF THE NORTHERN CWA TONIGHT...AND THEREFORE HAVE
BUMPED UP SOUTH WINDS TO 20-25 MPH AND MENTIONED GUSTS TO 40 MPH
IN THE ZONES. THIS FORECAST IS NOT OF HIGH CONFIDENCE...PARTLY
BECAUSE IT MAY BE THE FIRST NWS FORECAST THAT HAS EVER TRIED TO
INCLUDE A RISK OF HEATBURSTS IN A ZONE FORECAST. HOWEVER LOOKING
AT ALL OF THE DATA...THE SETUP TONIGHT LOOKS VERY FAVORABLE FOR
PERIOD OF GUSTY SOUTH WINDS BENEATH ELEVATED RADAR ECHOES. WE
SHALL SEE.
A STRONG SHORTWAVE TROUGH WILL ROTATE THROUGH THE SOUTHERN PLAINS
TOMORROW AND WILL PUSH THE DRYLINE FARTHER TO THE EAST INTO THE NW
ZONES. WITH DAYTIME HEATING...CIN SHOULD BE LOW ENOUGH OVER THE NW
ZONES FOR ISOLATED SEVERE STORMS TO DEVELOP IN THE AFTERNOON.
WIND FIELDS WILL STRENGTHEN A BIT AND SUPERCELL STORM MOTION WILL
BE EASTERLY. WEST TO EAST STORM TRACKS ON SUNDAY EVENING MEANS
POPS WILL COVER THE AREAS NORTH OF I-20. LOW LEVEL HELICITY RAMPS
UP AROUND SUNSET SUNDAY EVENING AND IF SUPERCELLS CAN OVERCOME THE
WEAK CIN AND TAP INTO SURFACE PARCELS...A TORNADO THREAT WILL
EXIST. MONDAY LOOKS LIKE A CARBON COPY OF SUNDAY/S PATTERN WITH
THE MAIN FEATURES IN THE SAME PLACE...JUST A LITTLE WEAKER CIN SO
POPS ARE SLIGHTLY HIGHER/FARTHER SOUTH. TEMPS WILL REMAIN NEAR
PERSISTENCE AND WINDS WILL BE BREEZY SUNDAY AND MONDAY.
ON TUESDAY THE UPPER TROUGH WILL BEGIN TO FINALLY MOVE EAST AND
THIS WILL PUSH A COLD FRONT INTO THE NW ZONES TUESDAY AFTERNOON.
SCATTERED TO NUMEROUS STORMS SHOULD FIRE ALONG THE COLD FRONT
TUESDAY AFTERNOON AND WORK EAST AND SOUTHEAST ACROSS MUCH OF THE
AREA INTO TUESDAY NIGHT. RAINFALL MAY BE WIDESPREAD AND AVERAGE
1/2 TO 1 INCH. SEVERE WEATHER WILL BE A CONCERN GIVEN HIGH
INSTABILITY AND ADEQUATE DEEP LAYER SHEAR.
THE FRONT WILL PUSH THROUGH THE REGION AND DRIER AIR WILL END RAIN
CHANCES FROM NORTH TO SOUTH WEDNESDAY. LOW TEMPS WILL COOL A BIT
AND INTO THE 60S DUE TO THE LOWER DEWPOINTS...BUT HIGHS WILL
CONTINUE IN THE MID 80S TO NEAR 90 THROUGH THE REMAINDER OF THE
WEEK. WILL KEEP THE FORECAST DRY AS AN UPPER RIDGE SETTLES INTO
THE AREA...BUT WE MAY HAVE TO WATCH FOR NW FLOW MCS ACTIVITY ON
FRIDAY NIGHT IN THE NW ZONES. TOO FAR OUT TO RELY ON THE MODEL
FORECASTS FOR THIS POSSIBILITY AT THIS TIME.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 90 72 89 72 / 20 10 20 10 20
WACO, TX 72 90 73 90 73 / 10 5 5 5 10
PARIS, TX 70 88 70 87 70 / 20 10 20 10 40
DENTON, TX 73 90 71 89 70 / 20 10 20 20 30
MCKINNEY, TX 73 89 71 88 71 / 20 10 20 10 30
DALLAS, TX 75 91 74 90 74 / 20 10 20 10 20
TERRELL, TX 72 88 71 89 73 / 10 5 20 10 20
CORSICANA, TX 71 89 72 89 73 / 10 5 5 5 10
TEMPLE, TX 71 89 73 90 73 / 5 5 5 5 10
MINERAL WELLS, TX 71 93 70 92 71 / 20 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS64 KFWD 182024
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
324 PM CDT SAT MAY 18 2013
.DISCUSSION...
A SLOW MOVING UPPER LEVEL TROUGH OVER THE PLAINS WILL PUT THE
REGION IN AN ACTIVE WEATHER PATTERN THROUGH TUESDAY WITH SEVERE
WEATHER POSSIBLE EACH DAY. PRIMARILY THE NORTHWEST/NORTHERN PARTS
OF THE CWA WILL BE IMPACTED BY CONVECTION TONIGHT THROUGH
MONDAY...BUT THE CENTRAL AND SOUTHERN CWA WILL BE UNDER THE GUN
FOR A WIDESPREAD RAIN EVENT TUESDAY AFTERNOON AND EVENING. THE
MAIN CHANGE WITH THIS FORECAST CONCERNS TONIGHT...AND THE ADDITION
OF POPS FOR AREAS NORTH OF I-20...NOT NECESSARILY FOR SUPERCELL
TYPE CONVECTION...BUT FOR VERY HIGH BASED WEAK CONVECTION THAT
COULD CAUSE STRONG GUSTY WINDS VIA HEATBURSTS LATE THIS EVENING.
THIS AFTERNOON THE DRY LINE REMAINS WELL TO THE WEST OF THE REGION
AND SHORT-TERM GUIDANCE SUGGESTS IT WILL STAY AS FAR WEST AS A
CHILDRESS TO SAN ANGELO LINE. THIS RESULTS IN SOME CONCERNS ABOUT
WHETHER SURFACE BASED CONVECTION WILL INITIATE CLOSE ENOUGH TO
ENTER THE CWA. MID LEVEL WESTERLY FLOW IS STRONGER TODAY...AND
THEREFORE STORM MOTIONS WOULD BE MORE EASTERLY. SURFACE BASED
CONVECTION WOULD HAVE ENOUGH SHEAR AND INSTABILITY TO BECOME
SUPERCELLS AND PRODUCE SIGNIFICANT SEVERE WEATHER. LOCAL OBJECTIVE
ANALYSIS INDICATES THE BEST AXIS OF INSTABILITY AND DIMINISHED CIN
IS TO THE WEST OF THE CWA...WITH THE AIRMASS OVER OUR WESTERN
COUNTIES NOT QUITE AS UNSTABLE WITH CAPE AT 1500-2500 J/KG AND
HIGHER CIN DUE TO DEWPOINTS DROPPING INTO THE LOW 60S. WATER VAPOR
LOOP AND MODEL GUIDANCE DOES INDICATE A SHORTWAVE IS APPROACHING
FROM THE SOUTHWEST AND THE LIFT PROVIDED BY THIS FEATURE SHOULD
ALLOW SURFACE BASED CONVECTION TO INITIATE AND ORGANIZE WEST OF
THE CWA. SOME OF THIS ACTIVITY SHOULD ENTER THE NW ZONES...BUT
BELIEVE THE CELLS MAY WEAKEN A BIT AND BECOME ELEVATED DUE TO THE
SLIGHTLY LESS FAVORABLE ENVIRONMENT. IN SUMMARY...A SEVERE THREAT
EXIST FOR PRIMARILY HAIL/WIND...AND POPS ARE NEAR 20-30 PERCENT IN
THE NW ZONES EARLY THIS EVENING. THE RISK FOR GIANT HAIL OR
TORNADOES DOES NOT LOOK AS HIGH AS IT DID YESTERDAY IN OUR CWA.
CURRENTLY...WEAK ELEVATED CONVECTION BASED AT AROUND 14000FT
CONTINUES TO BUBBLE UP OVER THE WESTERN ZONES. MOST OF THE PRECIP
IS EVAPORATING BEFORE REACHING THE GROUND...BUT THIS ELEVATED
MOISTURE PLUME LOOKS LIKE IT WILL HAVE IMPLICATIONS ON THE FORECAST
OVER THE NORTHERN HALF OF THE AREA TONIGHT. ESSENTIALLY THERE ARE
A FEW MODELS NOW INDICATING A MOISTURE PLUME FROM 500-600MB
ENTERING THE NORTHERN HALF OF THE AREA...LIKELY ASSOCIATED WITH
ANVILS FROM STORMS TO THE WEST. THE ISSUE IS THAT THIS MOISTURE
WILL BE WITHIN AN AREA OF DRY ADIABATIC LAPSE RATES...AND
COINCIDES WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. THE STAGE
IS SET FOR SCATTERED ELEVATED CONVECTION WITH BASES ABOVE 12000FT.
MOST OF THE RAIN WILL EVAPORATE DUE TO VERY DRY AIR BELOW 600MB...
BUT SPORADIC LIGHTNING STRIKES WILL BE POSSIBLE TONIGHT.
MEANWHILE...A 50KT SOUTHERLY LOW LEVEL JET WILL BE DEVELOPING AND
THE ENVIRONMENT WILL BE FAVORABLE FOR THIS HIGH BASED CONVECTION
TO TRANSFER STRONG WINDS TO THE SURFACE IN WHAT IS TECHNICALLY A
TYPE OF HEATBURST. THIS IS TOUGH TO COMMUNICATE TO THE PUBLIC IN
SIMPLE TERMS...BUT THE POPS ARE FOR MEASURABLE RAIN AND THE CHANCE
FOR THAT IS LOW. HOWEVER GUSTY WINDS AND LIGHT RAIN MAY AFFECT A
LARGE PORTION OF THE NORTHERN CWA TONIGHT...AND THEREFORE HAVE
BUMPED UP SOUTH WINDS TO 20-25 MPH AND MENTIONED GUSTS TO 40 MPH
IN THE ZONES. THIS FORECAST IS NOT OF HIGH CONFIDENCE...PARTLY
BECAUSE IT MAY BE THE FIRST NWS FORECAST THAT HAS EVER TRIED TO
INCLUDE A RISK OF HEATBURSTS IN A ZONE FORECAST. HOWEVER LOOKING
AT ALL OF THE DATA...THE SETUP TONIGHT LOOKS VERY FAVORABLE FOR
PERIOD OF GUSTY SOUTH WINDS BENEATH ELEVATED RADAR ECHOES. WE
SHALL SEE.
A STRONG SHORTWAVE TROUGH WILL ROTATE THROUGH THE SOUTHERN PLAINS
TOMORROW AND WILL PUSH THE DRYLINE FARTHER TO THE EAST INTO THE NW
ZONES. WITH DAYTIME HEATING...CIN SHOULD BE LOW ENOUGH OVER THE NW
ZONES FOR ISOLATED SEVERE STORMS TO DEVELOP IN THE AFTERNOON.
WIND FIELDS WILL STRENGTHEN A BIT AND SUPERCELL STORM MOTION WILL
BE EASTERLY. WEST TO EAST STORM TRACKS ON SUNDAY EVENING MEANS
POPS WILL COVER THE AREAS NORTH OF I-20. LOW LEVEL HELICITY RAMPS
UP AROUND SUNSET SUNDAY EVENING AND IF SUPERCELLS CAN OVERCOME THE
WEAK CIN AND TAP INTO SURFACE PARCELS...A TORNADO THREAT WILL
EXIST. MONDAY LOOKS LIKE A CARBON COPY OF SUNDAY/S PATTERN WITH
THE MAIN FEATURES IN THE SAME PLACE...JUST A LITTLE WEAKER CIN SO
POPS ARE SLIGHTLY HIGHER/FARTHER SOUTH. TEMPS WILL REMAIN NEAR
PERSISTENCE AND WINDS WILL BE BREEZY SUNDAY AND MONDAY.
ON TUESDAY THE UPPER TROUGH WILL BEGIN TO FINALLY MOVE EAST AND
THIS WILL PUSH A COLD FRONT INTO THE NW ZONES TUESDAY AFTERNOON.
SCATTERED TO NUMEROUS STORMS SHOULD FIRE ALONG THE COLD FRONT
TUESDAY AFTERNOON AND WORK EAST AND SOUTHEAST ACROSS MUCH OF THE
AREA INTO TUESDAY NIGHT. RAINFALL MAY BE WIDESPREAD AND AVERAGE
1/2 TO 1 INCH. SEVERE WEATHER WILL BE A CONCERN GIVEN HIGH
INSTABILITY AND ADEQUATE DEEP LAYER SHEAR.
THE FRONT WILL PUSH THROUGH THE REGION AND DRIER AIR WILL END RAIN
CHANCES FROM NORTH TO SOUTH WEDNESDAY. LOW TEMPS WILL COOL A BIT
AND INTO THE 60S DUE TO THE LOWER DEWPOINTS...BUT HIGHS WILL
CONTINUE IN THE MID 80S TO NEAR 90 THROUGH THE REMAINDER OF THE
WEEK. WILL KEEP THE FORECAST DRY AS AN UPPER RIDGE SETTLES INTO
THE AREA...BUT WE MAY HAVE TO WATCH FOR NW FLOW MCS ACTIVITY ON
FRIDAY NIGHT IN THE NW ZONES. TOO FAR OUT TO RELY ON THE MODEL
FORECASTS FOR THIS POSSIBILITY AT THIS TIME.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 90 72 89 72 / 20 10 20 10 20
WACO, TX 72 90 73 90 73 / 10 5 5 5 10
PARIS, TX 70 88 70 87 70 / 20 10 20 10 40
DENTON, TX 73 90 71 89 70 / 20 10 20 20 30
MCKINNEY, TX 73 89 71 88 71 / 20 10 20 10 30
DALLAS, TX 75 91 74 90 74 / 20 10 20 10 20
TERRELL, TX 72 88 71 89 73 / 10 5 20 10 20
CORSICANA, TX 71 89 72 89 73 / 10 5 5 5 10
TEMPLE, TX 71 89 73 90 73 / 5 5 5 5 10
MINERAL WELLS, TX 71 93 70 92 71 / 20 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS64 KFWD 181727 AAB
AFDFWD
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1227 PM CDT SAT MAY 18 2013
.AVIATION...
THE NORTH/CENTRAL TEXAS TAF SITES WILL BE BREEZY AND
VFR THIS AFTERNOON THROUGH LATE TONIGHT. THEN...MVFR CIGS ARE
EXPECTED TO ADVECT ACROSS THE SITES...AROUND 09Z AT KACT AND BY 11Z
ACROSS THE METROPLEX. THIS IS DUE TO A STRENGTHENING LLJ TONIGHT
THAT WILL BE IN THE 40-45 KNOT RANGE LATE TONIGHT THROUGH SUNDAY MORNING.
WINDS ARE EXPECTED TO BE AROUND 18KTS WITH HIGHER GUSTS THIS
AFTERNOON...SLIGHTLY WEAKER THIS EVENING THEN INCREASING BY 06Z TO
17G27KT. WINDS ON SUNDAY SHOULD BE 20G30KTS OR JUST A BIT HIGHER
MIDDAY THROUGH LATE AFTERNOON.
A SHORTWAVE MAY DEVELOP SOME ELEVATED CONVECTION NORTH OF I-20
LATE TONIGHT. DUE TO FORECAST SOUNDING PROFILES...WE HAVE A
CONCERN ABOUT THE POTENTIAL OF HEAT BURSTS RESULTING FROM ANY
ACTIVITY THAT PASSES FAIRLY CLOSE TO THE NORTHERN MOST TAF
SITES...KAFW/KDFW/KDAL. 75
&&
.UPDATE...
12Z FWD SOUNDING SHOWS MOISTURE DEPTH HAS BEEN REDUCED AS COMPARED
TO YESTERDAY...WHICH SHOULD CAUSE DEWPOINTS TO MIX OUT INTO THE
LOW 60S WEST TO MID 60S CENTRAL AND EAST. IN ADDITION...THE LOW
LEVEL THERMAL PROFILE HAS WARMED A FEW DEGREES OVER YESTERDAY
WHICH MEANS HIGH TEMPS WILL BE A COUPLE DEGREES WARMER TODAY FOR
MOST AREAS. LIGHT ECHOES IN THE SOUTHWEST CWA THIS MORNING ARE
ASSOCIATED WITH WEAK MID LEVEL CONVECTION AND PRECIP IS LIKELY NOT
REACHING THE GROUND. PREVIOUS FORECAST WAS GENERALLY ON TRACK AND
A JUST A FEW CHANGES TO HOURLY GRIDS WERE MADE FOR TRENDS.
CONCERNING THE CONVECTIVE POTENTIAL FOR THIS AFTERNOON AND
EVENING...IT STILL APPEARS THE WESTERN AND NORTHWESTERN COUNTIES
HAVE SOME THREAT OF SEVERE STORMS BUT THERE ARE SOME MIXED
SIGNALS IN THE DATA TODAY. THE STRONG CAP WILL CONTINUE TO BE THE
PRIMARY IMPEDANCE FOR CONVECTIVE ACTIVITY. A LOWER MOISTURE DEPTH
MAY RESULT IN DEWPOINTS MIXING OUT MORE THAN FORECAST WHICH WOULD
KEEP CIN VALUES TOO HIGH. THE DRYLINE WILL ALSO BE POSITIONED
FARTHER WEST TODAY AND ALONG A LINE FROM VERNON TO SAN ANGELO.
HOWEVER...THE MODEL DATA IS IN AGREEMENT THAT A WEAK SHORTWAVE
WILL MOVE ACROSS THE NORTHWEST ZONES THIS EVENING AND RESULT IN
HEIGHT FALLS. THIS BIT OF FORCING WOULD HELP TO ERODE THE CAP AND
WOULD FAVOR CONVECTIVE INITIATION OCCURRING TO THE WEST OF THE CWA
LATE THIS AFTERNOON. MID LEVEL WESTERLY WIND FIELDS ARE SLIGHTLY
STRONGER TODAY AND STORMS WOULD HAVE THE POTENTIAL TO MOVE MORE
EASTERLY AND INTO THE WESTERN CWA BY EARLY THIS EVENING. THE RUC
KEEPS ALL ACTIVITY TO OUR WEST...BUT THE HRRR AND 12Z NAM ARE
BRINGING IT INTO THE WESTERN ZONES. SOME OF THE OTHER HI-RES
MODELS ARE NOT EVEN INITIATING...SO AGAIN POPS WILL BE GENERALLY
JUST 20 PERCENT WEST OF A GAINESVILLE TO MINERAL WELLS TO
GOLDTHWAITE DUE TO INITIATION AND STORM MOTION UNCERTAINTIES. DUE
TO STEEP LAPSE RATES...INSTABILITY WILL BE HIGH WITH CAPES LIKELY
OVER 3000 J/KG AT PEAK HEATING...AND THE MAIN SEVERE THREAT IN OUR
CWA WILL BE LARGE HAIL. ACROSS THE CENTRAL AND EASTERN ZONES THE
CAP WILL REMAIN TOO STRONG FOR SURFACE BASED CONVECTION...BUT
THESE AREAS MAY EXPERIENCE SPRINKLES AND GUSTY WINDS FROM STORM
ANVILS LATER THIS EVENING.
TR.92
&&
.SHORT TERM...
A SHORTWAVE DISTURBANCE WAS SEEN VIA WATER VAPOR SATELLITE IMAGERY
EARLY THIS MORNING ROTATING THROUGH CENTRAL/EASTERN NEW MEXICO.
THIS FEATURE WILL EJECT WITHIN INCREASING SOUTHWEST FLOW ALOFT
ACROSS WEST TX/OK BY AFTERNOON. THIS WILL DEEPEN AND MOVE THE
SURFACE DRYLINE INTO THE SOUTH PLAINS BY EARLY EVENING. LIFT FROM
BOTH OF THESE FEATURES WILL COMBINE WITH HIGH TEMPERATURES AROUND
100 DEGREES AND THE RESULTING VERY HIGH INSTABILITY FOR THE
DEVELOPMENT OF A FEW SUPERCELLS LATE IN THE DAY. THIS IS TYPICALLY
THE TIME OF THE YEAR/MID MAY-LATE JUNE/ THAT THE DRYLINE OUT WEST IS
THE MOST ACTIVE...USUALLY PRODUCING DIURNAL SEVERE WEATHER IN THE
LATE AFTERNOONS AND EARLY EVENINGS. EXPECT MORE DISCRETE SUPERCELLS
LATE TODAY AND THIS EVENING IN AND NEAR OUR FAR WESTERN COUNTIES.
CURRENT SHEAR AND BUNKERS METHOD INDICATE THERE WILL BE MORE
STEERING CURRENTS TO THE NORTHEAST VERSUS YESTERDAY WITH UPPER
TROUGH APPROACHING. HOWEVER...AS WITH ANY SUPERCELL DEVIANT
MOTIONS CANNOT BE RULED OUT ONCE ANY MESOCYCLONES DEVELOP WITHIN
THE STORMS THEMSELVES. DESPITE RELATIVELY HIGH LCLS WITH THE HOT
AND UNSTABLE AIRMASS...JUST ABOUT ALL TYPES OF SEVERE WEATHER WILL
BE POSSIBLE WITH THIS ACTIVITY. EXPECT ABOUT 20-30 PERCENT COVERAGE
OF SEVERE STORMS ACROSS THE NORTHWEST COUNTIES. THE INVERSION
STRENGTHENS ONCE AGAIN BY LATE EVENING AND EXPECT THE MAJORITY OF
ACTIVITY TO DIMINISH QUICKLY.
THE NEXT ROUND OF SEVERE WEATHER LATE SUNDAY WILL LIKELY BE MORE
ACROSS THE NORTHERN TIER COUNTIES VERSUS JUST THE WEST...AS A
NEGATIVE TILT SHORTWAVE DISTURBANCE ROTATES ACROSS THE TX/OK
PANHANDLES INTO WESTERN OK/KS. THE SURFACE DRYLINE WILL HAVE A
BETTER PUSH TO EAST ACROSS THOSE AREAS NORTH OF I-20 IN RESPONSE
TO THIS SHORTWAVE. THE HIGHER COVERAGE OF SEVERE WEATHER AND RISK
WILL BE OVER EASTERN OK INTO THE OZARKS...BUT SHOULD ZIPPER A FEW
STORMS SOUTH-SOUTHWEST ACROSS THE RED RIVER BY EVENING. ALL THREATS
WILL BE POSSIBLE ONCE AGAIN.
&&
.CLIMATE...
YESTERDAY (MAY 17) WAS THE FIRST 90-DEGREE DAY AT DFW AIRPORT THIS
YEAR. IT WAS ALSO THE FIRST TIME NORTH TEXAS HAS SEEN 100 DEGREES
IN 2013. GRAHAM HIT 101...AND BRECKENRIDGE PEAKED AT 104.
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 93 73 92 72 91 / 5 5 10 20 10
WACO, TX 92 71 91 73 90 / 5 5 10 10 10
PARIS, TX 88 70 87 68 87 / 5 5 5 20 10
DENTON, TX 93 72 90 72 90 / 5 10 10 20 10
MCKINNEY, TX 90 72 89 71 88 / 5 5 5 20 10
DALLAS, TX 93 73 91 74 91 / 5 5 10 20 10
TERRELL, TX 90 71 90 71 89 / 5 5 5 10 10
CORSICANA, TX 91 71 89 73 90 / 5 5 5 10 10
TEMPLE, TX 92 71 91 72 90 / 5 5 10 10 10
MINERAL WELLS, TX 96 70 94 69 95 / 5 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
000
FXUS64 KFWD 181556
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1056 AM CDT SAT MAY 18 2013
.UPDATE...
12Z FWD SOUNDING SHOWS MOISTURE DEPTH HAS BEEN REDUCED AS COMPARED
TO YESTERDAY...WHICH SHOULD CAUSE DEWPOINTS TO MIX OUT INTO THE
LOW 60S WEST TO MID 60S CENTRAL AND EAST. IN ADDITION...THE LOW
LEVEL THERMAL PROFILE HAS WARMED A FEW DEGREES OVER YESTERDAY
WHICH MEANS HIGH TEMPS WILL BE A COUPLE DEGREES WARMER TODAY FOR
MOST AREAS. LIGHT ECHOES IN THE SOUTHWEST CWA THIS MORNING ARE
ASSOCIATED WITH WEAK MID LEVEL CONVECTION AND PRECIP IS LIKELY NOT
REACHING THE GROUND. PREVIOUS FORECAST WAS GENERALLY ON TRACK AND
A JUST A FEW CHANGES TO HOURLY GRIDS WERE MADE FOR TRENDS.
CONCERNING THE CONVECTIVE POTENTIAL FOR THIS AFTERNOON AND
EVENING...IT STILL APPEARS THE WESTERN AND NORTHWESTERN COUNTIES
HAVE SOME THREAT OF SEVERE STORMS BUT THERE ARE SOME MIXED
SIGNALS IN THE DATA TODAY. THE STRONG CAP WILL CONTINUE TO BE THE
PRIMARY IMPEDANCE FOR CONVECTIVE ACTIVITY. A LOWER MOISTURE DEPTH
MAY RESULT IN DEWPOINTS MIXING OUT MORE THAN FORECAST WHICH WOULD
KEEP CIN VALUES TOO HIGH. THE DRYLINE WILL ALSO BE POSITIONED
FARTHER WEST TODAY AND ALONG A LINE FROM VERNON TO SAN ANGELO.
HOWEVER...THE MODEL DATA IS IN AGREEMENT THAT A WEAK SHORTWAVE
WILL MOVE ACROSS THE NORTHWEST ZONES THIS EVENING AND RESULT IN
HEIGHT FALLS. THIS BIT OF FORCING WOULD HELP TO ERODE THE CAP AND
WOULD FAVOR CONVECTIVE INITIATION OCCURRING TO THE WEST OF THE CWA
LATE THIS AFTERNOON. MID LEVEL WESTERLY WIND FIELDS ARE SLIGHTLY
STRONGER TODAY AND STORMS WOULD HAVE THE POTENTIAL TO MOVE MORE
EASTERLY AND INTO THE WESTERN CWA BY EARLY THIS EVENING. THE RUC
KEEPS ALL ACTIVITY TO OUR WEST...BUT THE HRRR AND 12Z NAM ARE
BRINGING IT INTO THE WESTERN ZONES. SOME OF THE OTHER HI-RES
MODELS ARE NOT EVEN INITIATING...SO AGAIN POPS WILL BE GENERALLY
JUST 20 PERCENT WEST OF A GAINESVILLE TO MINERAL WELLS TO
GOLDTHWAITE DUE TO INITIATION AND STORM MOTION UNCERTAINTIES. DUE
TO STEEP LAPSE RATES...INSTABILITY WILL BE HIGH WITH CAPES LIKELY
OVER 3000 J/KG AT PEAK HEATING...AND THE MAIN SEVERE THREAT IN OUR
CWA WILL BE LARGE HAIL. ACROSS THE CENTRAL AND EASTERN ZONES THE
CAP WILL REMAIN TOO STRONG FOR SURFACE BASED CONVECTION...BUT
THESE AREAS MAY EXPERIENCE SPRINKLES AND GUSTY WINDS FROM STORM
ANVILS LATER THIS EVENING.
TR.92
&&
.AVIATION...
/12Z TAFS/
CONCERNS...NOCTURNAL STRATUS AND THUNDERSTORMS TO THE WEST.
STRATUS HAS SLOWLY MADE ITS WAY UP THE I-35 CORRIDOR OVERNIGHT. A
SIGNIFICANT WESTERLY COMPONENT ABOVE THE STRATUS IS REDUCING THE
DEPTH OF THE LAYER AND SHOULD KEEP THE DECK SOUTH AND EAST OF
METROPLEX TAF SITES.
ISOLATED THUNDERSTORMS MAY DEVELOP ACROSS WESTERN PORTIONS OF
NORTH TEXAS LATE THIS AFTERNOON. SOME OF THE ACTIVITY MAY APPROACH
THE I-35 CORRIDOR THIS EVENING. MAY IMPACT WEST DEPARTURES AND
NORTHWEST ARRIVALS...BUT DO NOT ANTICIPATE ANY ISSUES AT TAF
SITES.
A MORE VIGOROUS LLJ SUNDAY MORNING SHOULD IMPROVE THE PROBABILITY
OF MORNING STRATUS.
25
&&
.SHORT TERM...
A SHORTWAVE DISTURBANCE WAS SEEN VIA WATER VAPOR SATELLITE IMAGERY
EARLY THIS MORNING ROTATING THROUGH CENTRAL/EASTERN NEW MEXICO.
THIS FEATURE WILL EJECT WITHIN INCREASING SOUTHWEST FLOW ALOFT
ACROSS WEST TX/OK BY AFTERNOON. THIS WILL DEEPEN AND MOVE THE
SURFACE DRYLINE INTO THE SOUTH PLAINS BY EARLY EVENING. LIFT FROM
BOTH OF THESE FEATURES WILL COMBINE WITH HIGH TEMPERATURES AROUND
100 DEGREES AND THE RESULTING VERY HIGH INSTABILITY FOR THE
DEVELOPMENT OF A FEW SUPERCELLS LATE IN THE DAY. THIS IS TYPICALLY
THE TIME OF THE YEAR/MID MAY-LATE JUNE/ THAT THE DRYLINE OUT WEST IS
THE MOST ACTIVE...USUALLY PRODUCING DIURNAL SEVERE WEATHER IN THE
LATE AFTERNOONS AND EARLY EVENINGS. EXPECT MORE DISCRETE SUPERCELLS
LATE TODAY AND THIS EVENING IN AND NEAR OUR FAR WESTERN COUNTIES.
CURRENT SHEAR AND BUNKERS METHOD INDICATE THERE WILL BE MORE
STEERING CURRENTS TO THE NORTHEAST VERSUS YESTERDAY WITH UPPER
TROUGH APPROACHING. HOWEVER...AS WITH ANY SUPERCELL DEVIANT
MOTIONS CANNOT BE RULED OUT ONCE ANY MESOCYCLONES DEVELOP WITHIN
THE STORMS THEMSELVES. DESPITE RELATIVELY HIGH LCLS WITH THE HOT
AND UNSTABLE AIRMASS...JUST ABOUT ALL TYPES OF SEVERE WEATHER WILL
BE POSSIBLE WITH THIS ACTIVITY. EXPECT ABOUT 20-30 PERCENT COVERAGE
OF SEVERE STORMS ACROSS THE NORTHWEST COUNTIES. THE INVERSION
STRENGTHENS ONCE AGAIN BY LATE EVENING AND EXPECT THE MAJORITY OF
ACTIVITY TO DIMINISH QUICKLY.
THE NEXT ROUND OF SEVERE WEATHER LATE SUNDAY WILL LIKELY BE MORE
ACROSS THE NORTHERN TIER COUNTIES VERSUS JUST THE WEST...AS A
NEGATIVE TILT SHORTWAVE DISTURBANCE ROTATES ACROSS THE TX/OK
PANHANDLES INTO WESTERN OK/KS. THE SURFACE DRYLINE WILL HAVE A
BETTER PUSH TO EAST ACROSS THOSE AREAS NORTH OF I-20 IN RESPONSE
TO THIS SHORTWAVE. THE HIGHER COVERAGE OF SEVERE WEATHER AND RISK
WILL BE OVER EASTERN OK INTO THE OZARKS...BUT SHOULD ZIPPER A FEW
STORMS SOUTH-SOUTHWEST ACROSS THE RED RIVER BY EVENING. ALL THREATS
WILL BE POSSIBLE ONCE AGAIN.
&&
.CLIMATE...
YESTERDAY (MAY 17) WAS THE FIRST 90-DEGREE DAY AT DFW AIRPORT THIS
YEAR. IT WAS ALSO THE FIRST TIME NORTH TEXAS HAS SEEN 100 DEGREES
IN 2013. GRAHAM HIT 101...AND BRECKENRIDGE PEAKED AT 104.
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 93 73 92 72 91 / 5 5 10 20 10
WACO, TX 92 71 91 73 90 / 5 5 10 10 10
PARIS, TX 88 70 87 68 87 / 5 5 5 20 10
DENTON, TX 93 72 90 72 90 / 5 10 10 20 10
MCKINNEY, TX 90 72 89 71 88 / 5 5 5 20 10
DALLAS, TX 93 73 91 74 91 / 5 5 10 20 10
TERRELL, TX 90 71 90 71 89 / 5 5 5 10 10
CORSICANA, TX 91 71 89 73 90 / 5 5 5 10 10
TEMPLE, TX 92 71 91 72 90 / 5 5 10 10 10
MINERAL WELLS, TX 96 70 94 69 95 / 5 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS64 KFWD 181210 AAA
AFDFWD
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
710 AM CDT SAT MAY 18 2013
.AVIATION...
/12Z TAFS/
CONCERNS...NOCTURNAL STRATUS AND THUNDERSTORMS TO THE WEST.
STRATUS HAS SLOWLY MADE ITS WAY UP THE I-35 CORRIDOR OVERNIGHT. A
SIGNIFICANT WESTERLY COMPONENT ABOVE THE STRATUS IS REDUCING THE
DEPTH OF THE LAYER AND SHOULD KEEP THE DECK SOUTH AND EAST OF
METROPLEX TAF SITES.
ISOLATED THUNDERSTORMS MAY DEVELOP ACROSS WESTERN PORTIONS OF
NORTH TEXAS LATE THIS AFTERNOON. SOME OF THE ACTIVITY MAY APPROACH
THE I-35 CORRIDOR THIS EVENING. MAY IMPACT WEST DEPARTURES AND
NORTHWEST ARRIVALS...BUT DO NOT ANTICIPATE ANY ISSUES AT TAF
SITES.
A MORE VIGOROUS LLJ SUNDAY MORNING SHOULD IMPROVE THE PROBABILITY
OF MORNING STRATUS.
25
&&
.CLIMATE...
YESTERDAY (MAY 17) WAS THE FIRST 90-DEGREE DAY AT DFW AIRPORT THIS
YEAR. IT WAS ALSO THE FIRST TIME NORTH TEXAS HAS SEEN 100 DEGREES
IN 2013. GRAHAM HIT 101...AND BRECKENRIDGE PEAKED AT 104.
&&
.SHORT TERM...
A SHORTWAVE DISTURBANCE WAS SEEN VIA WATER VAPOR SATELLITE IMAGERY
EARLY THIS MORNING ROTATING THROUGH CENTRAL/EASTERN NEW MEXICO.
THIS FEATURE WILL EJECT WITHIN INCREASING SOUTHWEST FLOW ALOFT
ACROSS WEST TX/OK BY AFTERNOON. THIS WILL DEEPEN AND MOVE THE
SURFACE DRYLINE INTO THE SOUTH PLAINS BY EARLY EVENING. LIFT FROM
BOTH OF THESE FEATURES WILL COMBINE WITH HIGH TEMPERATURES AROUND
100 DEGREES AND THE RESULTING VERY HIGH INSTABILITY FOR THE
DEVELOPMENT OF A FEW SUPERCELLS LATE IN THE DAY. THIS IS TYPICALLY
THE TIME OF THE YEAR/MID MAY-LATE JUNE/ THAT THE DRYLINE OUT WEST IS
THE MOST ACTIVE...USUALLY PRODUCING DIURNAL SEVERE WEATHER IN THE
LATE AFTERNOONS AND EARLY EVENINGS. EXPECT MORE DISCRETE SUPERCELLS
LATE TODAY AND THIS EVENING IN AND NEAR OUR FAR WESTERN COUNTIES.
CURRENT SHEAR AND BUNKERS METHOD INDICATE THERE WILL BE MORE
STEERING CURRENTS TO THE NORTHEAST VERSUS YESTERDAY WITH UPPER
TROUGH APPROACHING. HOWEVER...AS WITH ANY SUPERCELL DEVIANT
MOTIONS CANNOT BE RULED OUT ONCE ANY MESOCYCLONES DEVELOP WITHIN
THE STORMS THEMSELVES. DESPITE RELATIVELY HIGH LCLS WITH THE HOT
AND UNSTABLE AIRMASS...JUST ABOUT ALL TYPES OF SEVERE WEATHER WILL
BE POSSIBLE WITH THIS ACTIVITY. EXPECT ABOUT 20-30 PERCENT COVERAGE
OF SEVERE STORMS ACROSS THE NORTHWEST COUNTIES. THE INVERSION
STRENGTHENS ONCE AGAIN BY LATE EVENING AND EXPECT THE MAJORITY OF
ACTIVITY TO DIMINISH QUICKLY.
THE NEXT ROUND OF SEVERE WEATHER LATE SUNDAY WILL LIKELY BE MORE
ACROSS THE NORTHERN TIER COUNTIES VERSUS JUST THE WEST...AS A
NEGATIVE TILT SHORTWAVE DISTURBANCE ROTATES ACROSS THE TX/OK
PANHANDLES INTO WESTERN OK/KS. THE SURFACE DRYLINE WILL HAVE A
BETTER PUSH TO EAST ACROSS THOSE AREAS NORTH OF I-20 IN RESPONSE
TO THIS SHORTWAVE. THE HIGHER COVERAGE OF SEVERE WEATHER AND RISK
WILL BE OVER EASTERN OK INTO THE OZARKS...BUT SHOULD ZIPPER A FEW
STORMS SOUTH-SOUTHWEST ACROSS THE RED RIVER BY EVENING. ALL THREATS
WILL BE POSSIBLE ONCE AGAIN.
&&
.SYNOPSIS...
AN UPPER RIDGE HAS SHIFTED INTO THE SOUTHERN/CENTRAL PLAINS AND
INTO THE OZARKS/MISSISSIPPI VALLEY THE PAST 12 HOURS OR SO. THE
CAPPING INVERSION HAS LOWERED AND STRENGTHENED COMPARED TO 24 HOURS
AGO WHEN PREDAWN/ELEVATED SEVERE STORMS DEVELOPED AROUND DAYBREAK
FRIDAY. VERY STEEP LAPSE RATES ALOFT OVER 8 DEG C/KM BETWEEN
575-850MB AND SBCAPE VALUES NEAR 4000 J/KG EXISTED THIS PAST
EVENING ON THE 00Z FWD SOUNDING. A LONGWAVE UPPER TROUGH WAS
ORGANIZING ACROSS THE GREAT BASIN AND CENTRAL ROCKIES EARLY THIS
MORNING. THIS FEATURE WILL BE A PLAYER ALONG WITH THE SURFACE
DRYLINE...THEN EVENTUALLY A WEAK COLD FRONT FOR EPISODES OF SEVERE
WEATHER ACROSS THE PLAINS INTO THE OZARKS THE NEXT SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 93 73 92 72 91 / 5 5 10 20 10
WACO, TX 92 71 91 73 90 / 5 5 10 10 10
PARIS, TX 88 70 87 68 87 / 10 5 5 20 10
DENTON, TX 93 72 90 72 90 / 5 10 10 20 10
MCKINNEY, TX 90 72 89 71 88 / 5 5 5 20 10
DALLAS, TX 93 73 91 74 91 / 5 5 10 20 10
TERRELL, TX 90 71 90 71 89 / 5 5 5 10 10
CORSICANA, TX 91 71 89 73 90 / 5 5 5 10 10
TEMPLE, TX 92 71 91 72 90 / 5 5 10 10 10
MINERAL WELLS, TX 96 70 94 69 95 / 5 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/05
000
FXUS64 KFWD 180903
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
403 AM CDT SAT MAY 18 2013
...SEVERE WEATHER THREAT WILL EXIST ACROSS PARTS OF NORTHERN/WESTERN
NORTH TEXAS THIS WEEKEND AND INTO THE EARLY NEXT WEEK...
.SYNOPSIS...
AN UPPER RIDGE HAS SHIFTED INTO THE SOUTHERN/CENTRAL PLAINS AND
INTO THE OZARKS/MISSISSIPPI VALLEY THE PAST 12 HOURS OR SO. THE
CAPPING INVERSION HAS LOWERED AND STRENGTHENED COMPARED TO 24 HOURS
AGO WHEN PREDAWN/ELEVATED SEVERE STORMS DEVELOPED AROUND DAYBREAK
FRIDAY. VERY STEEP LAPSE RATES ALOFT OVER 8 DEG C/KM BETWEEN
575-850MB AND SBCAPE VALUES NEAR 4000 J/KG EXISTED THIS PAST
EVENING ON THE 00Z FWD SOUNDING. A LONGWAVE UPPER TROUGH WAS
ORGANIZING ACROSS THE GREAT BASIN AND CENTRAL ROCKIES EARLY THIS
MORNING. THIS FEATURE WILL BE A PLAYER ALONG WITH THE SURFACE
DRYLINE...THEN EVENTUALLY A WEAK COLD FRONT FOR EPISODES OF SEVERE
WEATHER ACROSS THE PLAINS INTO THE OZARKS THE NEXT SEVERAL DAYS.
&&
.SHORT TERM...
A SHORTWAVE DISTURBANCE WAS SEEN VIA WATER VAPOR SATELLITE IMAGERY
EARLY THIS MORNING ROTATING THROUGH CENTRAL/EASTERN NEW MEXICO.
THIS FEATURE WILL EJECT WITHIN INCREASING SOUTHWEST FLOW ALOFT
ACROSS WEST TX/OK BY AFTERNOON. THIS WILL DEEPEN AND MOVE THE
SURFACE DRYLINE INTO THE SOUTH PLAINS BY EARLY EVENING. LIFT FROM
BOTH OF THESE FEATURES WILL COMBINE WITH HIGH TEMPERATURES AROUND
100 DEGREES AND THE RESULTING VERY HIGH INSTABILITY FOR THE
DEVELOPMENT OF A FEW SUPERCELLS LATE IN THE DAY. THIS IS TYPICALLY
THE TIME OF THE YEAR/MID MAY-LATE JUNE/ THAT THE DRYLINE OUT WEST IS
THE MOST ACTIVE...USUALLY PRODUCING DIURNAL SEVERE WEATHER IN THE
LATE AFTERNOONS AND EARLY EVENINGS. EXPECT MORE DISCRETE SUPERCELLS
LATE TODAY AND THIS EVENING IN AND NEAR OUR FAR WESTERN COUNTIES.
CURRENT SHEAR AND BUNKERS METHOD INDICATE THERE WILL BE MORE
STEERING CURRENTS TO THE NORTHEAST VERSUS YESTERDAY WITH UPPER
TROUGH APPROACHING. HOWEVER...AS WITH ANY SUPERCELL DEVIANT
MOTIONS CANNOT BE RULED OUT ONCE ANY MESOCYCLONES DEVELOP WITHIN
THE STORMS THEMSELVES. DESPITE RELATIVELY HIGH LCLS WITH THE HOT
AND UNSTABLE AIRMASS...JUST ABOUT ALL TYPES OF SEVERE WEATHER WILL
BE POSSIBLE WITH THIS ACTIVITY. EXPECT ABOUT 20-30 PERCENT COVERAGE
OF SEVERE STORMS ACROSS THE NORTHWEST COUNTIES. THE INVERSION
STRENGTHENS ONCE AGAIN BY LATE EVENING AND EXPECT THE MAJORITY OF
ACTIVITY TO DIMINISH QUICKLY.
THE NEXT ROUND OF SEVERE WEATHER LATE SUNDAY WILL LIKELY BE MORE
ACROSS THE NORTHERN TIER COUNTIES VERSUS JUST THE WEST...AS A
NEGATIVE TILT SHORTWAVE DISTURBANCE ROTATES ACROSS THE TX/OK
PANHANDLES INTO WESTERN OK/KS. THE SURFACE DRYLINE WILL HAVE A
BETTER PUSH TO EAST ACROSS THOSE AREAS NORTH OF I-20 IN RESPONSE
TO THIS SHORTWAVE. THE HIGHER COVERAGE OF SEVERE WEATHER AND RISK
WILL BE OVER EASTERN OK INTO THE OZARKS...BUT SHOULD ZIPPER A FEW
STORMS SOUTH-SOUTHWEST ACROSS THE RED RIVER BY EVENING. ALL THREATS
WILL BE POSSIBLE ONCE AGAIN.
&&
.LONG TERM...
FOR LATER MONDAY INTO EARLY WEDNESDAY...ZONAL FLOW ALOFT WILL
STRENGTHEN OVER NORTH TEXAS WITH A BROAD UPPER TROUGH OVER THE
NORTHERN CONUS. THIS WILL HELP A WEAK COLD FRONT MOVE INTO THE
AREA TUESDAY/TUESDAY NIGHT WITH HIGHER CHANCES FOR STORMS. A
SEVERE WEATHER RISK WILL LIKELY CONTINUE. THE MAIN FORCING FROM
THE MAIN UPPER TROUGH WILL LIFT OUT OVER THE PLAINS TUESDAY NIGHT
INTO EARLY WEDNESDAY AND WILL ASSIST THE SOUTHEAST MOVEMENT OF
THE COLD FRONT THROUGH THE AREA. THE COLD FRONT AND THREAT FOR
STORMS WILL END FROM WEST TO EAST ON WEDNESDAY. WE FINALLY SEE A
QUIET PERIOD FOR THE LATTER HALF OF THE WEEK...THE THE UPPER
TROUGH DEPARTS TO THE EAST AND IS REPLACED BY AN UPPER RIDGE.
THE DRYLINE WILL BE ACTIVE TO OUR WEST...BUT EXPECT THE UPPER
RIDGE AND RESULTING STRONG CAP TO KEEP OUR CWA SUPPRESSED AND DRY.
NEXT WEEKEND LOOKS MORE MUDDLED AS WE GO BEYOND THE 7 DAY
FORECAST AND HAVE LEFT A DRY FORECAST FOR NOW.
.TEMPERATURES...
LOOK FOR TEMPERATURES TO STAY ABOVE NORMAL THROUGH MONDAY WITH
BREEZY AND HUMID CONDITIONS. SOME MODIFICATION BACK TOWARD
SEASONABLE NORMALS MAY OCCUR BRIEFLY AFTER THE COLD FRONT AROUND
MID WEEK...BEFORE WARMING BACK UP ABOVE NORMAL AGAIN LATE IN THE
WEEK.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 93 73 92 72 91 / 5 5 10 20 10
WACO, TX 92 71 91 73 90 / 5 5 10 10 10
PARIS, TX 88 70 87 68 87 / 10 5 5 20 10
DENTON, TX 93 72 90 72 90 / 5 10 10 20 10
MCKINNEY, TX 90 72 89 71 88 / 5 5 5 20 10
DALLAS, TX 93 73 91 74 91 / 5 5 10 20 10
TERRELL, TX 90 71 90 71 89 / 5 5 5 10 10
CORSICANA, TX 91 71 89 73 90 / 5 5 5 10 10
TEMPLE, TX 92 71 91 72 90 / 5 5 10 10 10
MINERAL WELLS, TX 96 70 94 69 95 / 5 20 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/
000
FXUS64 KFWD 180448
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1148 PM CDT FRI MAY 17 2013
.UPDATE...
SENT OUT A QUICK FORECAST UPDATE TO BUMP UP POPS A BIT FOR AREAS
ALONG AND WEST OF A LINE FROM BOWIE TO LAMPASAS. THE PRIMARY
REASON FOR THIS IS THAT AFTERNOON HIGH RESOLUTION MODEL GUIDANCE
IS MORE AGGRESSIVE WITH ISOLATED THUNDERSTORM INITIATION EAST OF
THE DRYLINE NEAR OUR FAR WESTERN CWA LATE TOMORROW AFTERNOON. THIS
ISOLATED CONVECTION IS INITIATED IN A MODELED ENVIRONMENT
CHARACTERIZED BY 3000 TO 3500 J/KG OF CAPE AND WEAK TO MODERATE
VALUES OF DEEP LAYER BULK SHEAR. THE COMBINATION OF POTENTIAL
ENERGY FOR CONVECTION AND DEEP LAYER SHEAR SHOULD SUPPORT
SUPERCELL THUNDERSTORMS ASSUMING CONVECTION INITIATES AS HIGH
RESOLUTION MODELS ADVERTISE. THERE WILL BE A CAP IN PLACE OVER
MUCH OF NORTH TEXAS...SO ONCE AGAIN THINK THUNDERSTORMS WILL
STRUGGLE TO MOVE EAST OF THIS LINE FROM BOWIE TO LAMPASAS TOMORROW
AFTERNOON OR EVENING. LARGE HAIL AND DAMAGING WINDS WOULD BE THE
PRIMARY HAZARDS...HOWEVER A TORNADO THREAT CANNOT BE RULED OUT.
BACK TO THE CAP...THE 00Z FWD SOUNDING THIS EVENING SHOWED A STOUT
CAP WITH A DEEP DRY ADIABATIC LAYER EXTENDING ABOVE THE CAP FROM
850 MB UP PAST 600 MB. THIS LAYER HAS LAPSE RATES AS STEEP AS OUR
ATMOSPHERE WILL ALLOW AWAY FROM GROUND LEVEL. ANY PRECIPITATION
INTO THIS LAYER OF STEEP LAPSE RATES AND LOW RELATIVE HUMIDITY
WILL ACCELERATE AIR DOWNWARD QUICKLY AS THIS REPRESENTS THE IDEAL
ENVIRONMENT FOR RAIN DROPS TO EVAPORATE...ADDING NEGATIVE
BUOYANCY TO AIR THAT IS ALREADY HEADED TOWARDS THE EARTH. THIS
WILL LIKELY SUPPORT HEAT BURSTS THROUGHOUT THE OVERNIGHT HOURS
WHICH IS WHAT WAS HAPPENED IN COMANCHE EARLIER THIS EVENING. A
LIGHT TO MODERATE ELEVATED RAIN SHOWER MOVED OVER COMANCHE AND
CAUSE THE TEMPERATURE TO CLIMB 4 DEGREES WHILE THE DEW POINT
DROPPED 24 DEGREES AND WINDS GUSTED TO 57 MPH. GRANTED...WE DO NOT
EXPECT MUCH IN THE WAY OF RAIN SHOWER ACTIVITY ACROSS NORTH TX
TONIGHT...BUT THERE IS A WEAK SHORTWAVE TROUGH UPSTREAM...AND IT
WOULD NOT TAKE MUCH OF A RAIN SHOWER TO INITIATE A HEAT BURST. THIS
IS SOMETHING WE WILL BE KEEPING A CLOSE EYE ON THROUGHOUT THE
OVERNIGHT HOURS. NO OTHER SIGNIFICANT CHANGES WERE MADE TO THE
FORECAST.
CAVANAUGH
&&
.AVIATION...
AN UPDATE FROM THE 00Z TAFS...LIGHT RAIN...MOSTLY EVAPORATING
BEFORE REACHING THE GROUND. THIS LIGHT RAIN WAS CAUSING WINDS TO
GUST UP TO 35 TO 40 MPH TO THE NORTHWEST OF THE METROPLEX...AND
WAS PRODUCING ISOLATED CLOUD TO GROUND LIGHTNING STRIKES OVER THE
SAME AREAS. AT THIS TIME IT LOOKS LIKE THE CORE OF THIS LIGHT
ANVIL CLOUD PRECIP WILL REMAIN NORTHWEST OF DFW AIRPORT...BUT WILL
BE WATCHING LOCAL AREA OBS CLOSELY FOR ANY DEVIATION FROM THIS
THINKING. WENT AHEAD AND AMENDED KAFW FOR VCTS AND GUSTY WINDS
FROM 02 TO 03Z DUE TO A RECORDED LIGHTNING STRIKE AROUND HASLET.
THE STORMS OUT WEST ARE BEGINNING TO DISSIPATE...SO THE THREAT FOR
GUSTY WINDS AND ANVIL CLOUD LIGHTNING STRIKES IS EXPECTED TO
DIMINISH THROUGH 04Z AS WELL.
CAVANAUGH
.../PREVIOUS AVIATION DISCUSSION/...
FOR THE 00Z TAFS...TIMING THE ONSET OF MVFR CIGS AND WATCHING FOR
ANY IMPACT TO TAF SITES FROM STORMS OUT WEST ARE THE PRIMARY
FORECAST CONCERNS.
AT THIS TIME...THE CAP ALOFT OVER AREA TAF SITES LOOKS TOO STRONG
TO ALLOW STORMS ONGOING NEAR SAN SABA AND GRAHAM TO MOVE EAST AND
DIRECTLY IMPACT THE INTERSTATE 35 CORRIDOR. STORMS WOULD LIKELY
DISSIPATE BEFORE MINERAL WELLS IF THEY STARTED TO MOVE EAST THIS
EVENING. WILL CONTINUE TO MONITOR THE IMPACT OF THESE STORMS ON
AREA TAF SITES HOWEVER AS ANVIL CLOUDS ARE THICK AND HAVE PRODUCED
LIGHTNING STRIKES AS FAR EAST AS DECATUR THIS EVENING. IF
LIGHTNING LOOKS TO IMPACT LOCAL AREA TAFS THIS EVENING MAY HAVE TO
ISSUE AN AIRPORT WEATHER WARNING FOR DFW AND AMEND TAFS TO MENTION
A THUNDERSTORM WITH NO RAIN. AT THIS TIME...THE PRESENCE OF SOME
HIGHER MID-LEVEL RH PRECLUDES A LARGER THREAT FOR HEAT BURSTS
ASSOCIATED WITH ANVIL CLOUD LIGHT PRECIPITATION.
DID NOT CHANGE THE TIMING OF THE ONSET OF MVFR STRATUS OVER AREA
TAF SITES AT THIS TIME. THE LAMP GUIDANCE IS THE MOST AGGRESSIVE
WITH THIS WITH LESS SUPPORT FROM RAP AND NAM FORECAST SOUNDINGS.
WILL MONITOR UPSTREAM STRATUS DEVELOPMENT TONIGHT AND MAY PULL
STRATUS FROM THE FORECAST BY 06Z IF THERE IS LITTLE UPSTREAM
DEVELOPMENT.
CAVANAUGH
&&
.SHORT TERM...
DRYLINE IS SHARPENING AND IS LOCATED FROM OLNEY TO BRECKENRIDGE
TO BRADY. THE DRYLINE HAS LIKELY REACHED ITS EASTERN MOST
LOCATION...AS A SURFACE LOW INDUCED BY VERY HOT TEMPERATURES IS
DEEPENING NORTH OF ABILENE. THIS HAS CAUSED SURFACE WINDS TO BEGIN
TO BACK TO THE SOUTHEAST ACROSS THE NW CWA...WHICH WILL PULL RICH
LOW LEVEL MOISTURE CHARACTERIZED BY DEWPOINTS NEAR 70 DEGREES BACK
TO THE WEST. THE COMBINATION OF TEMPS NEAR 100 WITH THESE DEWPOINTS
AND NEARLY DRY ADIABATIC LAPSE RATES FROM 500MB TO 850MB HAS
PRODUCED AN EXTREMELY UNSTABLE AIRMASS ACROSS OUR WESTERN ZONES
THIS AFTERNOON. LOCAL OBJECTIVE ANALYSIS IS DEPICTING SBCAPE
AROUND 3500 J/KG...AND POCKETS OF CAPE OVER 4000 J/KG WILL BE
POSSIBLE THROUGH EARLY EVENING. THE STRONG CAP THAT WAS EVIDENT ON
THE MORNING SOUNDING IS CLOSE TO BEING ERODED OVER THE WESTERN
ZONES...OR THE WESTERN 2 COLUMNS OF COUNTIES OF THE CWA. ALONG AND
EAST OF A BOWIE TO GRANBURY TO TEMPLE LINE...OBJECTIVE ANALYSIS
SHOWS CIN WELL ABOVE 200 J/KG AND VIS SATELLITE CONFIRMS THE
PRESENCE OF STRONG CAPPING IN CUMULUS FIELD. WITHOUT UPPER LEVEL
FORCING THIS CAP SHOULD REMAIN...WITH HEATING NOT SUFFICIENT ALONE
TO WEAKEN IT.
CONVECTIVE INITIATION IS NOW OCCURRING SOUTHWEST OF BROWNWOOD AND
CUMULUS IS ORGANIZING TO THE WEST OF BRECKENRIDGE. THIS IS TO
THE WEST OF THE DRY LINE...BUT THIS IS ACTUALLY THE FAVORED
LOCATION FOR UPWARD MESOSCALE FORCING ASSOCIATED WITH DRYLINES.
OFTEN THE LOW MOISTURE CONTENT BEHIND THE DRY LINE IS NOT
SUFFICIENT TO PRODUCE CUMULUS OR PRECIPITATION SO WE CANT SEE THE
LIFT...BUT THIS DRY LINE SEEMS TO HAVE MORE MOISTURE TO WORK WITH.
ONCE THE INFANT UPDRAFTS ARE ADVECTED TO THE MOIST SIDE OF THE DRY
LINE...THEY TAP INTO RICHER MOISTURE AND OFTEN GROW INTO CELLS
THAT RADAR CAN SEE. NEEDLESS TO SAY...CONVECTIVE INITIATION IS A
CERTAINTY AT THIS POINT...BUT COVERAGE OF STORMS WILL BE FAIRLY
LOW DUE TO WEAK UPPER LEVEL FORCING AND THE STRONG CAP. POPS WILL
RANGE FROM 20-40 PERCENT ACROSS THE WESTERN THIRD OF THE CWA.
DEEP LAYER SHEAR IS ON THE LOW SIDE OF WHAT IS TYPICALLY FOUND IN
SUPERCELL ENVIRONMENTS...BUT EXTREME INSTABILITY WILL LIKELY
COMPENSATE. STORM MOTION WILL START OUT EAST BUT AS SUPERCELLS
ORGANIZE AND MATURE THEY WILL LIKELY TURN TO THE SOUTH. THIS
SOUTHWARD MOVEMENT WILL ENHANCE LOW LEVEL STORM RELATIVE
HELICITY...WHICH MAY REACH 150-200 MS/S2 ACROSS THE NW ZONES WHERE
AN ISOLATED TORNADO THREAT IS GREATEST. HOWEVER THE MAIN THREAT
WILL BE GIANT HAIL AND DAMAGING WINDS GIVEN THE EXTREME INSTABILITY
AND LARGE DEWPOINT SPREADS. SPC HAS JUST ISSUED A SEVERE WATCH FOR
THE WESTERN ZONES...AND AGAIN DUE TO THE STRONG CAP AND SOUTHERLY
STORM MOTION BELIEVE ALL SEVERE ACTIVITY WILL REMAIN WEST OF THE
I-35 CORRIDOR. SOME LINGERING AND ELEVATED ACTIVITY MAY IMPACT THE
CENTRAL ZONES LATE TONIGHT...BUT THIS REMAINS A LOW PROBABILITY
AND KEPT POPS OUT OF THE FORECAST.
TR.92
&&
.LONG TERM...
A STRONG CAP WILL REMAIN IN PLACE ACROSS NORTH TEXAS THROUGH
MONDAY...SO THE CONVECTIVE FORECAST WILL HINGE ON WHETHER FORCING
FROM THE DRY LINE OR UPPER LEVEL SHORTWAVES WILL BE PRESENT. THE
DRYLINE WILL HEAD FARTHER WEST SATURDAY...AND ALTHOUGH A WELL
DEFINED SHORTWAVE MOVES ACROSS THE REGION...BELIEVE STORM
INITIATION WILL BE WELL NW OF THE CWA. A FEW OF THESE CELLS MAY
TRACK INTO THE NORTHWESTERN PARTS OF THE CWA SATURDAY
EVENING...BUT WILL KEEP POPS LOW AND AT 20 PERCENT. ON SUNDAY THE
DRY LINE WILL MIX EAST AGAIN AND FLIRT WITH THE NW CWA...AND HAVE
POPS A LITTLE HIGHER...BUT STILL PRIMARILY OVER THE NW ZONES IN
THE AFTERNOON. SINCE THE TAIL END OF THE PLAINS TROUGH WILL PASS
THROUGH THE NORTHERN ZONES SUNDAY NIGHT...CONVECTION MAY SURVIVE
PAST SUNSET AND TRACK ACROSS THE AREA NORTH OF I-20. EXPECT THE
SAME PATTERN ON MONDAY AND POPS ARE SIMILAR TO SUNDAYS. GIVEN THE
INSTABILITY AND SHEAR PROFILES SEVERE STORMS ARE POSSIBLE WITH ANY
ACTIVITY SATURDAY THROUGH MONDAY. FOR TEMPERATURES...SATURDAY WILL
BE THE WARMEST DAY WITH HIGHS IN THE 90S MOST AREAS...BUT WINDS
WILL INCREASE A BIT SUNDAY AND MONDAY WHICH SHOULD SHAVE A COUPLE
DEGREES...WITH HIGHS IN THE UPPER 80S EAST TO MID 90S WEST. LOWS
WILL REMAIN MUGGY AND IN THE LOW-MID 70S...WITH TONIGHT THE
COOLEST DUE TO FEWER CLOUDS AND LIGHTER WINDS.
ON TUESDAY ANOTHER LOBE OF ENERGY WILL ROTATE AROUND THE PLAINS
TROUGH AND HELP PROPEL A WEAK COLD FRONT SOUTH INTO THE AREA. THE
FRONT/DRYLINE COMBINATION WILL REACH THE NW CWA AND BECOME A FOCUS
FOR CONVECTION BY TUESDAY AFTERNOON. STRONG FORCING ASSOCIATED
WITH THE UPPER SHORTWAVE TROUGH WILL ENHANCE LIFT...AND EXPECT
SCATTERED CONVECTION TO OCCUR TUESDAY AFTERNOON AND WORK
SOUTHEAST ACROSS THE AREA. HAVE BUMPED POPS UP TO CHANCE AS THIS
WILL BE THE BEST DAY FOR RAIN CHANCES. AGAIN...THERE IS A SEVERE
WEATHER THREAT WITH THIS CONVECTION AS WELL.
THE FRONT WILL NOT BE VERY STRONG...AND WINDS MAY NOT SPEND MUCH
OR ANY TIME FROM THE NORTH...BUT THE AXIS OF BEST MOISTURE AND
INSTABILITY SHOULD GET PUSHED SOUTHEAST OF THE AREA. WILL KEEP A
SLIGHT CHANCE OF CONVECTION WEDNESDAY...BUT THIS ACTIVITY IS NOT
EXPECTED TO BE VERY SIGNIFICANT. TEMPS WILL BE A LITTLE COOLER AS
HEIGHTS LOWER...AND THE SLIGHTLY DRIER AIR WILL HELP LOWS FALL TO
NEAR NORMAL. HAVE KEPT THE REMAINDER OF THE FORECAST DRY AS UPPER
LEVEL RIDGING BUILDS INTO THE AREA...WHICH IS WELL AGREED UPON BY
EXTENDED GUIDANCE.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 92 72 90 72 / 10 5 5 10 20
WACO, TX 70 92 72 91 73 / 10 5 5 10 10
PARIS, TX 69 88 70 87 68 / 10 10 5 5 20
DENTON, TX 70 93 72 90 72 / 10 10 10 10 30
MCKINNEY, TX 69 90 71 89 71 / 10 5 5 5 20
DALLAS, TX 73 93 74 91 74 / 10 5 5 10 20
TERRELL, TX 69 90 70 91 71 / 10 5 5 5 10
CORSICANA, TX 70 90 70 89 73 / 10 5 5 5 10
TEMPLE, TX 69 92 71 91 72 / 20 10 5 10 10
MINERAL WELLS, TX 71 96 69 94 70 / 20 10 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
000
FXUS64 KFWD 180213
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
913 PM CDT FRI MAY 17 2013
.AVIATION...
AN UPDATE FROM THE 00Z TAFS...LIGHT RAIN...MOSTLY EVAPORATING
BEFORE REACHING THE GROUND. THIS LIGHT RAIN WAS CAUSING WINDS TO
GUST UP TO 35 TO 40 MPH TO THE NORTHWEST OF THE METROPLEX...AND
WAS PRODUCING ISOLATED CLOUD TO GROUND LIGHTNING STRIKES OVER THE
SAME AREAS. AT THIS TIME IT LOOKS LIKE THE CORE OF THIS LIGHT
ANVIL CLOUD PRECIP WILL REMAIN NORTHWEST OF DFW AIRPORT...BUT WILL
BE WATCHING LOCAL AREA OBS CLOSELY FOR ANY DEVIATION FROM THIS
THINKING. WENT AHEAD AND AMENDED KAFW FOR VCTS AND GUSTY WINDS
FROM 02 TO 03Z DUE TO A RECORDED LIGHTNING STRIKE AROUND HASLET.
THE STORMS OUT WEST ARE BEGINNING TO DISSIPATE...SO THE THREAT FOR
GUSTY WINDS AND ANVIL CLOUD LIGHTNING STRIKES IS EXPECTED TO
DIMINISH THROUGH 04Z AS WELL.
CAVANAUGH
.../PREVIOUS AVIATION DISCUSSION/...
FOR THE 00Z TAFS...TIMING THE ONSET OF MVFR CIGS AND WATCHING FOR
ANY IMPACT TO TAF SITES FROM STORMS OUT WEST ARE THE PRIMARY
FORECAST CONCERNS.
AT THIS TIME...THE CAP ALOFT OVER AREA TAF SITES LOOKS TOO STRONG
TO ALLOW STORMS ONGOING NEAR SAN SABA AND GRAHAM TO MOVE EAST AND
DIRECTLY IMPACT THE INTERSTATE 35 CORRIDOR. STORMS WOULD LIKELY
DISSIPATE BEFORE MINERAL WELLS IF THEY STARTED TO MOVE EAST THIS
EVENING. WILL CONTINUE TO MONITOR THE IMPACT OF THESE STORMS ON
AREA TAF SITES HOWEVER AS ANVIL CLOUDS ARE THICK AND HAVE PRODUCED
LIGHTNING STRIKES AS FAR EAST AS DECATUR THIS EVENING. IF
LIGHTNING LOOKS TO IMPACT LOCAL AREA TAFS THIS EVENING MAY HAVE TO
ISSUE AN AIRPORT WEATHER WARNING FOR DFW AND AMEND TAFS TO MENTION
A THUNDERSTORM WITH NO RAIN. AT THIS TIME...THE PRESENCE OF SOME
HIGHER MID-LEVEL RH PRECLUDES A LARGER THREAT FOR HEAT BURSTS
ASSOCIATED WITH ANVIL CLOUD LIGHT PRECIPITATION.
DID NOT CHANGE THE TIMING OF THE ONSET OF MVFR STRATUS OVER AREA
TAF SITES AT THIS TIME. THE LAMP GUIDANCE IS THE MOST AGGRESSIVE
WITH THIS WITH LESS SUPPORT FROM RAP AND NAM FORECAST SOUNDINGS.
WILL MONITOR UPSTREAM STRATUS DEVELOPMENT TONIGHT AND MAY PULL
STRATUS FROM THE FORECAST BY 06Z IF THERE IS LITTLE UPSTREAM
DEVELOPMENT.
CAVANAUGH
&&
.SHORT TERM...
DRYLINE IS SHARPENING AND IS LOCATED FROM OLNEY TO BRECKENRIDGE
TO BRADY. THE DRYLINE HAS LIKELY REACHED ITS EASTERN MOST
LOCATION...AS A SURFACE LOW INDUCED BY VERY HOT TEMPERATURES IS
DEEPENING NORTH OF ABILENE. THIS HAS CAUSED SURFACE WINDS TO BEGIN
TO BACK TO THE SOUTHEAST ACROSS THE NW CWA...WHICH WILL PULL RICH
LOW LEVEL MOISTURE CHARACTERIZED BY DEWPOINTS NEAR 70 DEGREES BACK
TO THE WEST. THE COMBINATION OF TEMPS NEAR 100 WITH THESE DEWPOINTS
AND NEARLY DRY ADIABATIC LAPSE RATES FROM 500MB TO 850MB HAS
PRODUCED AN EXTREMELY UNSTABLE AIRMASS ACROSS OUR WESTERN ZONES
THIS AFTERNOON. LOCAL OBJECTIVE ANALYSIS IS DEPICTING SBCAPE
AROUND 3500 J/KG...AND POCKETS OF CAPE OVER 4000 J/KG WILL BE
POSSIBLE THROUGH EARLY EVENING. THE STRONG CAP THAT WAS EVIDENT ON
THE MORNING SOUNDING IS CLOSE TO BEING ERODED OVER THE WESTERN
ZONES...OR THE WESTERN 2 COLUMNS OF COUNTIES OF THE CWA. ALONG AND
EAST OF A BOWIE TO GRANBURY TO TEMPLE LINE...OBJECTIVE ANALYSIS
SHOWS CIN WELL ABOVE 200 J/KG AND VIS SATELLITE CONFIRMS THE
PRESENCE OF STRONG CAPPING IN CUMULUS FIELD. WITHOUT UPPER LEVEL
FORCING THIS CAP SHOULD REMAIN...WITH HEATING NOT SUFFICIENT ALONE
TO WEAKEN IT.
CONVECTIVE INITIATION IS NOW OCCURRING SOUTHWEST OF BROWNWOOD AND
CUMULUS IS ORGANIZING TO THE WEST OF BRECKENRIDGE. THIS IS TO
THE WEST OF THE DRY LINE...BUT THIS IS ACTUALLY THE FAVORED
LOCATION FOR UPWARD MESOSCALE FORCING ASSOCIATED WITH DRYLINES.
OFTEN THE LOW MOISTURE CONTENT BEHIND THE DRY LINE IS NOT
SUFFICIENT TO PRODUCE CUMULUS OR PRECIPITATION SO WE CANT SEE THE
LIFT...BUT THIS DRY LINE SEEMS TO HAVE MORE MOISTURE TO WORK WITH.
ONCE THE INFANT UPDRAFTS ARE ADVECTED TO THE MOIST SIDE OF THE DRY
LINE...THEY TAP INTO RICHER MOISTURE AND OFTEN GROW INTO CELLS
THAT RADAR CAN SEE. NEEDLESS TO SAY...CONVECTIVE INITIATION IS A
CERTAINTY AT THIS POINT...BUT COVERAGE OF STORMS WILL BE FAIRLY
LOW DUE TO WEAK UPPER LEVEL FORCING AND THE STRONG CAP. POPS WILL
RANGE FROM 20-40 PERCENT ACROSS THE WESTERN THIRD OF THE CWA.
DEEP LAYER SHEAR IS ON THE LOW SIDE OF WHAT IS TYPICALLY FOUND IN
SUPERCELL ENVIRONMENTS...BUT EXTREME INSTABILITY WILL LIKELY
COMPENSATE. STORM MOTION WILL START OUT EAST BUT AS SUPERCELLS
ORGANIZE AND MATURE THEY WILL LIKELY TURN TO THE SOUTH. THIS
SOUTHWARD MOVEMENT WILL ENHANCE LOW LEVEL STORM RELATIVE
HELICITY...WHICH MAY REACH 150-200 MS/S2 ACROSS THE NW ZONES WHERE
AN ISOLATED TORNADO THREAT IS GREATEST. HOWEVER THE MAIN THREAT
WILL BE GIANT HAIL AND DAMAGING WINDS GIVEN THE EXTREME INSTABILITY
AND LARGE DEWPOINT SPREADS. SPC HAS JUST ISSUED A SEVERE WATCH FOR
THE WESTERN ZONES...AND AGAIN DUE TO THE STRONG CAP AND SOUTHERLY
STORM MOTION BELIEVE ALL SEVERE ACTIVITY WILL REMAIN WEST OF THE
I-35 CORRIDOR. SOME LINGERING AND ELEVATED ACTIVITY MAY IMPACT THE
CENTRAL ZONES LATE TONIGHT...BUT THIS REMAINS A LOW PROBABILITY
AND KEPT POPS OUT OF THE FORECAST.
TR.92
&&
.LONG TERM...
A STRONG CAP WILL REMAIN IN PLACE ACROSS NORTH TEXAS THROUGH
MONDAY...SO THE CONVECTIVE FORECAST WILL HINGE ON WHETHER FORCING
FROM THE DRY LINE OR UPPER LEVEL SHORTWAVES WILL BE PRESENT. THE
DRYLINE WILL HEAD FARTHER WEST SATURDAY...AND ALTHOUGH A WELL
DEFINED SHORTWAVE MOVES ACROSS THE REGION...BELIEVE STORM
INITIATION WILL BE WELL NW OF THE CWA. A FEW OF THESE CELLS MAY
TRACK INTO THE NORTHWESTERN PARTS OF THE CWA SATURDAY
EVENING...BUT WILL KEEP POPS LOW AND AT 20 PERCENT. ON SUNDAY THE
DRY LINE WILL MIX EAST AGAIN AND FLIRT WITH THE NW CWA...AND HAVE
POPS A LITTLE HIGHER...BUT STILL PRIMARILY OVER THE NW ZONES IN
THE AFTERNOON. SINCE THE TAIL END OF THE PLAINS TROUGH WILL PASS
THROUGH THE NORTHERN ZONES SUNDAY NIGHT...CONVECTION MAY SURVIVE
PAST SUNSET AND TRACK ACROSS THE AREA NORTH OF I-20. EXPECT THE
SAME PATTERN ON MONDAY AND POPS ARE SIMILAR TO SUNDAYS. GIVEN THE
INSTABILITY AND SHEAR PROFILES SEVERE STORMS ARE POSSIBLE WITH ANY
ACTIVITY SATURDAY THROUGH MONDAY. FOR TEMPERATURES...SATURDAY WILL
BE THE WARMEST DAY WITH HIGHS IN THE 90S MOST AREAS...BUT WINDS
WILL INCREASE A BIT SUNDAY AND MONDAY WHICH SHOULD SHAVE A COUPLE
DEGREES...WITH HIGHS IN THE UPPER 80S EAST TO MID 90S WEST. LOWS
WILL REMAIN MUGGY AND IN THE LOW-MID 70S...WITH TONIGHT THE
COOLEST DUE TO FEWER CLOUDS AND LIGHTER WINDS.
ON TUESDAY ANOTHER LOBE OF ENERGY WILL ROTATE AROUND THE PLAINS
TROUGH AND HELP PROPEL A WEAK COLD FRONT SOUTH INTO THE AREA. THE
FRONT/DRYLINE COMBINATION WILL REACH THE NW CWA AND BECOME A FOCUS
FOR CONVECTION BY TUESDAY AFTERNOON. STRONG FORCING ASSOCIATED
WITH THE UPPER SHORTWAVE TROUGH WILL ENHANCE LIFT...AND EXPECT
SCATTERED CONVECTION TO OCCUR TUESDAY AFTERNOON AND WORK
SOUTHEAST ACROSS THE AREA. HAVE BUMPED POPS UP TO CHANCE AS THIS
WILL BE THE BEST DAY FOR RAIN CHANCES. AGAIN...THERE IS A SEVERE
WEATHER THREAT WITH THIS CONVECTION AS WELL.
THE FRONT WILL NOT BE VERY STRONG...AND WINDS MAY NOT SPEND MUCH
OR ANY TIME FROM THE NORTH...BUT THE AXIS OF BEST MOISTURE AND
INSTABILITY SHOULD GET PUSHED SOUTHEAST OF THE AREA. WILL KEEP A
SLIGHT CHANCE OF CONVECTION WEDNESDAY...BUT THIS ACTIVITY IS NOT
EXPECTED TO BE VERY SIGNIFICANT. TEMPS WILL BE A LITTLE COOLER AS
HEIGHTS LOWER...AND THE SLIGHTLY DRIER AIR WILL HELP LOWS FALL TO
NEAR NORMAL. HAVE KEPT THE REMAINDER OF THE FORECAST DRY AS UPPER
LEVEL RIDGING BUILDS INTO THE AREA...WHICH IS WELL AGREED UPON BY
EXTENDED GUIDANCE.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 92 72 90 72 / 10 5 5 10 20
WACO, TX 70 92 72 91 73 / 10 5 5 10 10
PARIS, TX 69 88 70 87 68 / 10 10 5 5 20
DENTON, TX 70 93 72 90 72 / 10 10 10 10 30
MCKINNEY, TX 69 90 71 89 71 / 10 5 5 5 20
DALLAS, TX 73 93 74 91 74 / 10 5 5 10 20
TERRELL, TX 69 90 70 91 71 / 10 5 5 5 10
CORSICANA, TX 70 90 70 89 73 / 10 5 5 5 10
TEMPLE, TX 69 92 71 91 72 / 20 10 5 10 10
MINERAL WELLS, TX 71 96 69 94 70 / 20 10 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
000
FXUS64 KFWD 172341
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
641 PM CDT FRI MAY 17 2013
.AVIATION...
FOR THE 00Z TAFS...TIMING THE ONSET OF MVFR CIGS AND WATCHING FOR
ANY IMPACT TO TAF SITES FROM STORMS OUT WEST ARE THE PRIMARY
FORECAST CONCERNS.
AT THIS TIME...THE CAP ALOFT OVER AREA TAF SITES LOOKS TOO STRONG
TO ALLOW STORMS ONGOING NEAR SAN SABA AND GRAHAM TO MOVE EAST AND
DIRECTLY IMPACT THE INTERSTATE 35 CORRIDOR. STORMS WOULD LIKELY
DISSIPATE BEFORE MINERAL WELLS IF THEY STARTED TO MOVE EAST THIS
EVENING. WILL CONTINUE TO MONITOR THE IMPACT OF THESE STORMS ON
AREA TAF SITES HOWEVER AS ANVIL CLOUDS ARE THICK AND HAVE PRODUCED
LIGHTNING STRIKES AS FAR EAST AS DECATUR THIS EVENING. IF
LIGHTNING LOOKS TO IMPACT LOCAL AREA TAFS THIS EVENING MAY HAVE TO
ISSUE AN AIRPORT WEATHER WARNING FOR DFW AND AMEND TAFS TO MENTION
A THUNDERSTORM WITH NO RAIN. AT THIS TIME...THE PRESENCE OF SOME
HIGHER MID-LEVEL RH PRECLUDES A LARGER THREAT FOR HEAT BURSTS
ASSOCIATED WITH ANVIL CLOUD LIGHT PRECIPITATION.
DID NOT CHANGE THE TIMING OF THE ONSET OF MVFR STRATUS OVER AREA
TAF SITES AT THIS TIME. THE LAMP GUIDANCE IS THE MOST AGGRESSIVE
WITH THIS WITH LESS SUPPORT FROM RAP AND NAM FORECAST SOUNDINGS.
WILL MONITOR UPSTREAM STRATUS DEVELOPMENT TONIGHT AND MAY PULL
STRATUS FROM THE FORECAST BY 06Z IF THERE IS LITTLE UPSTREAM
DEVELOPMENT.
CAVANAUGH
&&
.SHORT TERM...
DRYLINE IS SHARPENING AND IS LOCATED FROM OLNEY TO BRECKENRIDGE
TO BRADY. THE DRYLINE HAS LIKELY REACHED ITS EASTERN MOST
LOCATION...AS A SURFACE LOW INDUCED BY VERY HOT TEMPERATURES IS
DEEPENING NORTH OF ABILENE. THIS HAS CAUSED SURFACE WINDS TO BEGIN
TO BACK TO THE SOUTHEAST ACROSS THE NW CWA...WHICH WILL PULL RICH
LOW LEVEL MOISTURE CHARACTERIZED BY DEWPOINTS NEAR 70 DEGREES BACK
TO THE WEST. THE COMBINATION OF TEMPS NEAR 100 WITH THESE DEWPOINTS
AND NEARLY DRY ADIABATIC LAPSE RATES FROM 500MB TO 850MB HAS
PRODUCED AN EXTREMELY UNSTABLE AIRMASS ACROSS OUR WESTERN ZONES
THIS AFTERNOON. LOCAL OBJECTIVE ANALYSIS IS DEPICTING SBCAPE
AROUND 3500 J/KG...AND POCKETS OF CAPE OVER 4000 J/KG WILL BE
POSSIBLE THROUGH EARLY EVENING. THE STRONG CAP THAT WAS EVIDENT ON
THE MORNING SOUNDING IS CLOSE TO BEING ERODED OVER THE WESTERN
ZONES...OR THE WESTERN 2 COLUMNS OF COUNTIES OF THE CWA. ALONG AND
EAST OF A BOWIE TO GRANBURY TO TEMPLE LINE...OBJECTIVE ANALYSIS
SHOWS CIN WELL ABOVE 200 J/KG AND VIS SATELLITE CONFIRMS THE
PRESENCE OF STRONG CAPPING IN CUMULUS FIELD. WITHOUT UPPER LEVEL
FORCING THIS CAP SHOULD REMAIN...WITH HEATING NOT SUFFICIENT ALONE
TO WEAKEN IT.
CONVECTIVE INITIATION IS NOW OCCURRING SOUTHWEST OF BROWNWOOD AND
CUMULUS IS ORGANIZING TO THE WEST OF BRECKENRIDGE. THIS IS TO
THE WEST OF THE DRY LINE...BUT THIS IS ACTUALLY THE FAVORED
LOCATION FOR UPWARD MESOSCALE FORCING ASSOCIATED WITH DRYLINES.
OFTEN THE LOW MOISTURE CONTENT BEHIND THE DRY LINE IS NOT
SUFFICIENT TO PRODUCE CUMULUS OR PRECIPITATION SO WE CANT SEE THE
LIFT...BUT THIS DRY LINE SEEMS TO HAVE MORE MOISTURE TO WORK WITH.
ONCE THE INFANT UPDRAFTS ARE ADVECTED TO THE MOIST SIDE OF THE DRY
LINE...THEY TAP INTO RICHER MOISTURE AND OFTEN GROW INTO CELLS
THAT RADAR CAN SEE. NEEDLESS TO SAY...CONVECTIVE INITIATION IS A
CERTAINTY AT THIS POINT...BUT COVERAGE OF STORMS WILL BE FAIRLY
LOW DUE TO WEAK UPPER LEVEL FORCING AND THE STRONG CAP. POPS WILL
RANGE FROM 20-40 PERCENT ACROSS THE WESTERN THIRD OF THE CWA.
DEEP LAYER SHEAR IS ON THE LOW SIDE OF WHAT IS TYPICALLY FOUND IN
SUPERCELL ENVIRONMENTS...BUT EXTREME INSTABILITY WILL LIKELY
COMPENSATE. STORM MOTION WILL START OUT EAST BUT AS SUPERCELLS
ORGANIZE AND MATURE THEY WILL LIKELY TURN TO THE SOUTH. THIS
SOUTHWARD MOVEMENT WILL ENHANCE LOW LEVEL STORM RELATIVE
HELICITY...WHICH MAY REACH 150-200 MS/S2 ACROSS THE NW ZONES WHERE
AN ISOLATED TORNADO THREAT IS GREATEST. HOWEVER THE MAIN THREAT
WILL BE GIANT HAIL AND DAMAGING WINDS GIVEN THE EXTREME INSTABILITY
AND LARGE DEWPOINT SPREADS. SPC HAS JUST ISSUED A SEVERE WATCH FOR
THE WESTERN ZONES...AND AGAIN DUE TO THE STRONG CAP AND SOUTHERLY
STORM MOTION BELIEVE ALL SEVERE ACTIVITY WILL REMAIN WEST OF THE
I-35 CORRIDOR. SOME LINGERING AND ELEVATED ACTIVITY MAY IMPACT THE
CENTRAL ZONES LATE TONIGHT...BUT THIS REMAINS A LOW PROBABILITY
AND KEPT POPS OUT OF THE FORECAST.
TR.92
&&
.LONG TERM...
A STRONG CAP WILL REMAIN IN PLACE ACROSS NORTH TEXAS THROUGH
MONDAY...SO THE CONVECTIVE FORECAST WILL HINGE ON WHETHER FORCING
FROM THE DRY LINE OR UPPER LEVEL SHORTWAVES WILL BE PRESENT. THE
DRYLINE WILL HEAD FARTHER WEST SATURDAY...AND ALTHOUGH A WELL
DEFINED SHORTWAVE MOVES ACROSS THE REGION...BELIEVE STORM
INITIATION WILL BE WELL NW OF THE CWA. A FEW OF THESE CELLS MAY
TRACK INTO THE NORTHWESTERN PARTS OF THE CWA SATURDAY
EVENING...BUT WILL KEEP POPS LOW AND AT 20 PERCENT. ON SUNDAY THE
DRY LINE WILL MIX EAST AGAIN AND FLIRT WITH THE NW CWA...AND HAVE
POPS A LITTLE HIGHER...BUT STILL PRIMARILY OVER THE NW ZONES IN
THE AFTERNOON. SINCE THE TAIL END OF THE PLAINS TROUGH WILL PASS
THROUGH THE NORTHERN ZONES SUNDAY NIGHT...CONVECTION MAY SURVIVE
PAST SUNSET AND TRACK ACROSS THE AREA NORTH OF I-20. EXPECT THE
SAME PATTERN ON MONDAY AND POPS ARE SIMILAR TO SUNDAYS. GIVEN THE
INSTABILITY AND SHEAR PROFILES SEVERE STORMS ARE POSSIBLE WITH ANY
ACTIVITY SATURDAY THROUGH MONDAY. FOR TEMPERATURES...SATURDAY WILL
BE THE WARMEST DAY WITH HIGHS IN THE 90S MOST AREAS...BUT WINDS
WILL INCREASE A BIT SUNDAY AND MONDAY WHICH SHOULD SHAVE A COUPLE
DEGREES...WITH HIGHS IN THE UPPER 80S EAST TO MID 90S WEST. LOWS
WILL REMAIN MUGGY AND IN THE LOW-MID 70S...WITH TONIGHT THE
COOLEST DUE TO FEWER CLOUDS AND LIGHTER WINDS.
ON TUESDAY ANOTHER LOBE OF ENERGY WILL ROTATE AROUND THE PLAINS
TROUGH AND HELP PROPEL A WEAK COLD FRONT SOUTH INTO THE AREA. THE
FRONT/DRYLINE COMBINATION WILL REACH THE NW CWA AND BECOME A FOCUS
FOR CONVECTION BY TUESDAY AFTERNOON. STRONG FORCING ASSOCIATED
WITH THE UPPER SHORTWAVE TROUGH WILL ENHANCE LIFT...AND EXPECT
SCATTERED CONVECTION TO OCCUR TUESDAY AFTERNOON AND WORK
SOUTHEAST ACROSS THE AREA. HAVE BUMPED POPS UP TO CHANCE AS THIS
WILL BE THE BEST DAY FOR RAIN CHANCES. AGAIN...THERE IS A SEVERE
WEATHER THREAT WITH THIS CONVECTION AS WELL.
THE FRONT WILL NOT BE VERY STRONG...AND WINDS MAY NOT SPEND MUCH
OR ANY TIME FROM THE NORTH...BUT THE AXIS OF BEST MOISTURE AND
INSTABILITY SHOULD GET PUSHED SOUTHEAST OF THE AREA. WILL KEEP A
SLIGHT CHANCE OF CONVECTION WEDNESDAY...BUT THIS ACTIVITY IS NOT
EXPECTED TO BE VERY SIGNIFICANT. TEMPS WILL BE A LITTLE COOLER AS
HEIGHTS LOWER...AND THE SLIGHTLY DRIER AIR WILL HELP LOWS FALL TO
NEAR NORMAL. HAVE KEPT THE REMAINDER OF THE FORECAST DRY AS UPPER
LEVEL RIDGING BUILDS INTO THE AREA...WHICH IS WELL AGREED UPON BY
EXTENDED GUIDANCE.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 92 72 90 72 / 10 5 5 10 20
WACO, TX 70 92 72 91 73 / 10 5 5 10 10
PARIS, TX 69 88 70 87 68 / 10 10 5 5 20
DENTON, TX 70 93 72 90 72 / 10 10 10 10 30
MCKINNEY, TX 69 90 71 89 71 / 10 5 5 5 20
DALLAS, TX 73 93 74 91 74 / 10 5 5 10 20
TERRELL, TX 69 90 70 91 71 / 10 5 5 5 10
CORSICANA, TX 70 90 70 89 73 / 10 5 5 5 10
TEMPLE, TX 69 92 71 91 72 / 20 10 5 10 10
MINERAL WELLS, TX 71 96 69 94 70 / 20 10 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS64 KFWD 172043
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
343 PM CDT FRI MAY 17 2013
.SHORT TERM...
DRYLINE IS SHARPENING AND IS LOCATED FROM OLNEY TO BRECKENRIDGE
TO BRADY. THE DRYLINE HAS LIKELY REACHED ITS EASTERN MOST
LOCATION...AS A SURFACE LOW INDUCED BY VERY HOT TEMPERATURES IS
DEEPENING NORTH OF ABILENE. THIS HAS CAUSED SURFACE WINDS TO BEGIN
TO BACK TO THE SOUTHEAST ACROSS THE NW CWA...WHICH WILL PULL RICH
LOW LEVEL MOISTURE CHARACTERIZED BY DEWPOINTS NEAR 70 DEGREES BACK
TO THE WEST. THE COMBINATION OF TEMPS NEAR 100 WITH THESE DEWPOINTS
AND NEARLY DRY ADIABATIC LAPSE RATES FROM 500MB TO 850MB HAS
PRODUCED AN EXTREMELY UNSTABLE AIRMASS ACROSS OUR WESTERN ZONES
THIS AFTERNOON. LOCAL OBJECTIVE ANALYSIS IS DEPICTING SBCAPE
AROUND 3500 J/KG...AND POCKETS OF CAPE OVER 4000 J/KG WILL BE
POSSIBLE THROUGH EARLY EVENING. THE STRONG CAP THAT WAS EVIDENT ON
THE MORNING SOUNDING IS CLOSE TO BEING ERODED OVER THE WESTERN
ZONES...OR THE WESTERN 2 COLUMNS OF COUNTIES OF THE CWA. ALONG AND
EAST OF A BOWIE TO GRANBURY TO TEMPLE LINE...OBJECTIVE ANALYSIS
SHOWS CIN WELL ABOVE 200 J/KG AND VIS SATELLITE CONFIRMS THE
PRESENCE OF STRONG CAPPING IN CUMULUS FIELD. WITHOUT UPPER LEVEL
FORCING THIS CAP SHOULD REMAIN...WITH HEATING NOT SUFFICIENT ALONE
TO WEAKEN IT.
CONVECTIVE INITIATION IS NOW OCCURRING SOUTHWEST OF BROWNWOOD AND
CUMULUS IS ORGANIZING TO THE WEST OF BRECKENRIDGE. THIS IS TO
THE WEST OF THE DRY LINE...BUT THIS IS ACTUALLY THE FAVORED
LOCATION FOR UPWARD MESOSCALE FORCING ASSOCIATED WITH DRYLINES.
OFTEN THE LOW MOISTURE CONTENT BEHIND THE DRY LINE IS NOT
SUFFICIENT TO PRODUCE CUMULUS OR PRECIPITATION SO WE CANT SEE THE
LIFT...BUT THIS DRY LINE SEEMS TO HAVE MORE MOISTURE TO WORK WITH.
ONCE THE INFANT UPDRAFTS ARE ADVECTED TO THE MOIST SIDE OF THE DRY
LINE...THEY TAP INTO RICHER MOISTURE AND OFTEN GROW INTO CELLS
THAT RADAR CAN SEE. NEEDLESS TO SAY...CONVECTIVE INITIATION IS A
CERTAINTY AT THIS POINT...BUT COVERAGE OF STORMS WILL BE FAIRLY
LOW DUE TO WEAK UPPER LEVEL FORCING AND THE STRONG CAP. POPS WILL
RANGE FROM 20-40 PERCENT ACROSS THE WESTERN THIRD OF THE CWA.
DEEP LAYER SHEAR IS ON THE LOW SIDE OF WHAT IS TYPICALLY FOUND IN
SUPERCELL ENVIRONMENTS...BUT EXTREME INSTABILITY WILL LIKELY
COMPENSATE. STORM MOTION WILL START OUT EAST BUT AS SUPERCELLS
ORGANIZE AND MATURE THEY WILL LIKELY TURN TO THE SOUTH. THIS
SOUTHWARD MOVEMENT WILL ENHANCE LOW LEVEL STORM RELATIVE
HELICITY...WHICH MAY REACH 150-200 MS/S2 ACROSS THE NW ZONES WHERE
AN ISOLATED TORNADO THREAT IS GREATEST. HOWEVER THE MAIN THREAT
WILL BE GIANT HAIL AND DAMAGING WINDS GIVEN THE EXTREME INSTABILITY
AND LARGE DEWPOINT SPREADS. SPC HAS JUST ISSUED A SEVERE WATCH FOR
THE WESTERN ZONES...AND AGAIN DUE TO THE STRONG CAP AND SOUTHERLY
STORM MOTION BELIEVE ALL SEVERE ACTIVITY WILL REMAIN WEST OF THE
I-35 CORRIDOR. SOME LINGERING AND ELEVATED ACTIVITY MAY IMPACT THE
CENTRAL ZONES LATE TONIGHT...BUT THIS REMAINS A LOW PROBABILITY
AND KEPT POPS OUT OF THE FORECAST.
TR.92
&&
.LONG TERM...
A STRONG CAP WILL REMAIN IN PLACE ACROSS NORTH TEXAS THROUGH
MONDAY...SO THE CONVECTIVE FORECAST WILL HINGE ON WHETHER FORCING
FROM THE DRY LINE OR UPPER LEVEL SHORTWAVES WILL BE PRESENT. THE
DRYLINE WILL HEAD FARTHER WEST SATURDAY...AND ALTHOUGH A WELL
DEFINED SHORTWAVE MOVES ACROSS THE REGION...BELIEVE STORM
INITIATION WILL BE WELL NW OF THE CWA. A FEW OF THESE CELLS MAY
TRACK INTO THE NORTHWESTERN PARTS OF THE CWA SATURDAY
EVENING...BUT WILL KEEP POPS LOW AND AT 20 PERCENT. ON SUNDAY THE
DRY LINE WILL MIX EAST AGAIN AND FLIRT WITH THE NW CWA...AND HAVE
POPS A LITTLE HIGHER...BUT STILL PRIMARILY OVER THE NW ZONES IN
THE AFTERNOON. SINCE THE TAIL END OF THE PLAINS TROUGH WILL PASS
THROUGH THE NORTHERN ZONES SUNDAY NIGHT...CONVECTION MAY SURVIVE
PAST SUNSET AND TRACK ACROSS THE AREA NORTH OF I-20. EXPECT THE
SAME PATTERN ON MONDAY AND POPS ARE SIMILAR TO SUNDAYS. GIVEN THE
INSTABILITY AND SHEAR PROFILES SEVERE STORMS ARE POSSIBLE WITH ANY
ACTIVITY SATURDAY THROUGH MONDAY. FOR TEMPERATURES...SATURDAY WILL
BE THE WARMEST DAY WITH HIGHS IN THE 90S MOST AREAS...BUT WINDS
WILL INCREASE A BIT SUNDAY AND MONDAY WHICH SHOULD SHAVE A COUPLE
DEGREES...WITH HIGHS IN THE UPPER 80S EAST TO MID 90S WEST. LOWS
WILL REMAIN MUGGY AND IN THE LOW-MID 70S...WITH TONIGHT THE
COOLEST DUE TO FEWER CLOUDS AND LIGHTER WINDS.
ON TUESDAY ANOTHER LOBE OF ENERGY WILL ROTATE AROUND THE PLAINS
TROUGH AND HELP PROPEL A WEAK COLD FRONT SOUTH INTO THE AREA. THE
FRONT/DRYLINE COMBINATION WILL REACH THE NW CWA AND BECOME A FOCUS
FOR CONVECTION BY TUESDAY AFTERNOON. STRONG FORCING ASSOCIATED
WITH THE UPPER SHORTWAVE TROUGH WILL ENHANCE LIFT...AND EXPECT
SCATTERED CONVECTION TO OCCUR TUESDAY AFTERNOON AND WORK
SOUTHEAST ACROSS THE AREA. HAVE BUMPED POPS UP TO CHANCE AS THIS
WILL BE THE BEST DAY FOR RAIN CHANCES. AGAIN...THERE IS A SEVERE
WEATHER THREAT WITH THIS CONVECTION AS WELL.
THE FRONT WILL NOT BE VERY STRONG...AND WINDS MAY NOT SPEND MUCH
OR ANY TIME FROM THE NORTH...BUT THE AXIS OF BEST MOISTURE AND
INSTABILITY SHOULD GET PUSHED SOUTHEAST OF THE AREA. WILL KEEP A
SLIGHT CHANCE OF CONVECTION WEDNESDAY...BUT THIS ACTIVITY IS NOT
EXPECTED TO BE VERY SIGNIFICANT. TEMPS WILL BE A LITTLE COOLER AS
HEIGHTS LOWER...AND THE SLIGHTLY DRIER AIR WILL HELP LOWS FALL TO
NEAR NORMAL. HAVE KEPT THE REMAINDER OF THE FORECAST DRY AS UPPER
LEVEL RIDGING BUILDS INTO THE AREA...WHICH IS WELL AGREED UPON BY
EXTENDED GUIDANCE.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 92 72 90 72 / 10 5 5 10 20
WACO, TX 70 92 72 91 73 / 10 5 5 10 10
PARIS, TX 69 88 70 87 68 / 10 10 5 5 20
DENTON, TX 70 93 72 90 72 / 10 10 10 10 30
MCKINNEY, TX 69 90 71 89 71 / 10 5 5 5 20
DALLAS, TX 73 93 74 91 74 / 10 5 5 10 20
TERRELL, TX 69 90 70 91 71 / 10 5 5 5 10
CORSICANA, TX 70 90 70 89 73 / 10 5 5 5 10
TEMPLE, TX 69 92 71 91 72 / 20 10 5 10 10
MINERAL WELLS, TX 71 96 69 94 70 / 20 10 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
92/92
000
FXUS64 KFWD 172016
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
316 PM CDT FRI MAY 17 2013
.DISCUSSION...
DRYLINE IS SHARPENING AND IS LOCATED FROM OLNEY TO BRECKENRIDGE
TO BRADY. THE DRYLINE HAS LIKELY REACHED ITS EASTERN MOST
LOCATION...AS A SURFACE LOW INDUCED BY VERY HOT TEMPERATURES IS
DEEPENING NORTH OF ABILENE. THIS HAS CAUSED SURFACE WINDS TO BEGIN
TO BACK TO THE SOUTHEAST ACROSS THE NW CWA...WHICH WILL PULL RICH
LOW LEVEL MOISTURE CHARACTERIZED BY DEWPOINTS NEAR 70 DEGREES BACK
TO THE WEST. THE COMBINATION OF TEMPS NEAR 100 WITH THESE DEWPOINTS
AND NEARLY DRY ADIABATIC LAPSE RATES FROM 500MB TO 850MB HAS
PRODUCED AN EXTREMELY UNSTABLE AIRMASS ACROSS OUR WESTERN ZONES
THIS AFTERNOON. LOCAL OBJECTIVE ANALYSIS IS DEPICTING SBCAPE
AROUND 3500 J/KG...AND POCKETS OF CAPE OVER 4000 J/KG WILL BE
POSSIBLE THROUGH EARLY EVENING. THE STRONG CAP THAT WAS EVIDENT ON
THE MORNING SOUNDING IS CLOSE TO BEING ERODED OVER THE WESTERN
ZONES...OR THE WESTERN 2 COLUMNS OF COUNTIES OF THE CWA. ALONG AND
EAST OF A BOWIE TO GRANBURY TO TEMPLE LINE...OBJECTIVE ANALYSIS
SHOWS CIN WELL ABOVE 200 J/KG AND VIS SATELLITE CONFIRMS THE
PRESENCE OF STRONG CAPPING IN CUMULUS FIELD. WITHOUT UPPER LEVEL
FORCING THIS CAP SHOULD REMAIN...WITH HEATING NOT SUFFICIENT ALONE
TO WEAKEN IT.
CONVECTIVE INITIATION IS NOW OCCURRING SOUTHWEST OF BROWNWOOD AND
CUMULUS IS ORGANIZING TO THE WEST OF BRECKENRIDGE. THIS IS TO
THE WEST OF THE DRY LINE...BUT THIS IS ACTUALLY THE FAVORED
LOCATION FOR UPWARD MESOSCALE FORCING ASSOCIATED WITH DRYLINES.
OFTEN THE LOW MOISTURE CONTENT BEHIND THE DRY LINE IS NOT
SUFFICIENT TO PRODUCE CUMULUS OR PRECIPITATION SO WE CANT SEE THE
LIFT...BUT THIS DRY LINE SEEMS TO HAVE MORE MOISTURE TO WORK WITH.
ONCE THE INFANT UPDRAFTS ARE ADVECTED TO THE MOIST SIDE OF THE DRY
LINE...THEY TAP INTO RICHER MOISTURE AND OFTEN GROW INTO CELLS
THAT RADAR CAN SEE. NEEDLESS TO SAY...CONVECTIVE INITIATION IS A
CERTAINTY AT THIS POINT...BUT COVERAGE OF STORMS WILL BE FAIRLY
LOW DUE TO WEAK UPPER LEVEL FORCING AND THE STRONG CAP. POPS WILL
RANGE FROM 20-40 PERCENT ACROSS THE WESTERN THIRD OF THE CWA.
DEEP LAYER SHEAR IS ON THE LOW SIDE OF WHAT IS TYPICALLY FOUND IN
SUPERCELL ENVIRONMENTS...BUT EXTREME INSTABILITY WILL LIKELY
COMPENSATE. STORM MOTION WILL START OUT EAST BUT AS SUPERCELLS
ORGANIZE AND MATURE THEY WILL LIKELY TURN TO THE SOUTH. THIS
SOUTHWARD MOVEMENT WILL ENHANCE LOW LEVEL STORM RELATIVE
HELICITY...WHICH MAY REACH 150-200 MS/S2 ACROSS THE NW ZONES WHERE
AN ISOLATED TORNADO THREAT IS GREATEST. HOWEVER THE MAIN THREAT
WILL BE GIANT HAIL AND DAMAGING WINDS GIVEN THE EXTREME INSTABILITY
AND LARGE DEWPOINT SPREADS. SPC HAS JUST ISSUED A SEVERE WATCH FOR
THE WESTERN ZONES...AND AGAIN DUE TO THE STRONG CAP AND SOUTHERLY
STORM MOTION BELIEVE ALL SEVERE ACTIVITY WILL REMAIN WEST OF THE
I-35 CORRIDOR. SOME LINGERING AND ELEVATED ACTIVITY MAY IMPACT THE
CENTRAL ZONES LATE TONIGHT...BUT THIS REMAINS A LOW PROBABILITY
AND KEPT POPS OUT OF THE FORECAST.
THIS DISCUSSION WILL BE SENT AGAIN IN A FEW MINUTES WITH DETAILS
ON THE FORECAST BEYOND TONIGHT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 92 72 90 72 / 10 5 5 10 20
WACO, TX 70 92 72 91 73 / 10 5 5 10 10
PARIS, TX 69 88 70 87 68 / 10 10 5 5 20
DENTON, TX 70 93 72 90 72 / 10 10 10 10 30
MCKINNEY, TX 69 90 71 89 71 / 10 5 5 5 20
DALLAS, TX 73 93 74 91 74 / 10 5 5 10 20
TERRELL, TX 69 90 70 91 71 / 10 5 5 5 10
CORSICANA, TX 70 90 70 89 73 / 10 5 5 5 10
TEMPLE, TX 69 92 71 91 72 / 20 10 5 10 10
MINERAL WELLS, TX 71 96 69 94 70 / 20 10 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS64 KFWD 171723 AAB
AFDFWD
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1223 PM CDT FRI MAY 17 2013
.AVIATION...
CONCERNS...RETURN OF MVFR CIGS LATE TONIGHT.
CURRENT MVFR CIGS ACROSS THE METROPLEX SHOULD GO SCT030-040 FOR
MOST TAF SITES EARLY THIS AFTERNOON WHILE KFTW/KAFW MAY REMAIN
BKN030 THROUGH 20Z. AFTERWARD...VFR CONDITIONS WITH SOUTHERLY
WINDS 13-20KTS. EXPECT ANOTHER ROUND OF STRATUS LATE TONIGHT
08-10Z THAT WILL PERSIST UNTIL 15Z. VFR SKIES LATE MORNING THROUGH
LATE SATURDAY AFTERNOON. SURFACE WINDS SHOULD BE SEVERAL KNOTS
HIGHER ON SATURDAY AFTERNOON THAN THIS AFTERNOON.
AS FOR CONVECTION...MIDDAY CONVECTION BETWEEN KCRS-KLFK-KUTS WILL
PERSIST SEVERAL MORE HOURS AS THE CELLS PROPAGATE SOUTHEAST.
OTHERWISE...FORECAST SOUNDINGS SHOW ALL FWD TAF SITES REMAINING
STRONGLY CAPPED THROUGH THE FORECAST PERIOD. HOWEVER...FAR TO THE
WEST...A DRYLINE WILL NEAR A KCDS-KABI- KSJT LINE THIS AFTERNOON
AND SHOULD BE ABLE TO PRODUCE SEVERAL SUPERCELL THUNDERSTORMS
BETWEEN 21-23Z. NONE ARE EXPECTED TO AFFECT OUR TAF SITES. 75
&&
.UPDATE...
12Z FWD SOUNDING DEPICTS NEARLY DRY ADIABATIC LAPSE RATES FROM
850MB UP TO 500MB. CURRENTLY A WEAK SHORTWAVE WAS MOVING ACROSS
NORTH TEXAS IN NORTHWEST FLOW ALOFT AND WAS RESPONSIBLE FOR THE
ELEVATED CONVECTION OCCURRING OVER THE SOUTHEAST ZONES THIS
MORNING. THESE STORMS HAVE PRODUCED HAIL UP TO GOLF BALL SIZE AND
ARE A TESTAMENT TO THE STEEP LAPSE RATES ALOFT. THIS SHORTWAVE
WILL CONTINUE TO MOVE SOUTHEAST AND OUT OF THE AREA BY MIDDAY.
STRONG SURFACE HEATING ACROSS THE WESTERN ZONES WILL HELP PUSH
TEMPERATURES TO NEAR THE CENTURY MARK THIS AFTERNOON. A DRY LINE
WILL REACH A LINE FROM GRAHAM TO COMANCHE TO LLANO. SHORT TERM
MODELS DEPICT DEWPOINTS IN THE LOW TO MID 70S AHEAD OF THE DRY
LINE...BUT THIS IS PROBABLY TOO HIGH. BELIEVE DEWPOINTS WILL MIX
OUT INTO THE UPPER 60S. NONETHELESS...THIS WILL CONTRIBUTE TO
EXTREME INSTABILITY WITH SURFACE BASED CAPE VALUES ABOVE 4000
J/KG. UNLIKE THE EVENT ON WEDNESDAY...THE CAP WILL BE MUCH
STRONGER TODAY AND WILL REQUIRE STRONG HEATING AND THE MESOSCALE
FORCING PROVIDED BY A DRY LINE TO BE OVERCOME. GIVEN A REASONABLE
FORECAST TEMP/DEWPOINT COMBINATION OF 99 OVER 68 AHEAD OF THE DRY
LINE...THIS SHOULD BE SUFFICIENT FOR THE CAP TO BREAK.
SEVERAL OF THE HI-RES CONVECTION ALLOWING MODELS AND THE LAST 2
RUNS OF THE NAM ARE SHOWING STORM INITIATION LATE THIS
AFTERNOON...AND ARE FOCUSING IN ON THE AREA NEAR THE LLANO
UPLIFT...WHICH WOULD AFFECT OUR SW ZONES AND ALSO ANOTHER AREA
NEAR GRAHAM AND BRECKENRIDGE. DEEP LAYER SHEAR IS NOT OVERLY
STRONG AND IS ON THE LOW END OF THE ALLOWABLE LEVEL FOR
SUPERCELLS. HOWEVER THE HIGH INSTABILITY WILL LIKELY COMPENSATE
AND ALLOW FOR SUPERCELL MODES. SUPERCELL STORM MOTION TECHNIQUES
BASED ONLY ON WIND PROFILES ARE EAST AT 10KT...BUT IN CASES OF
HIGH INSTABILITY AND WEAK FLOW...THESE SUPERCELLS WILL LIKELY HEAD
SLOWLY SOUTHEAST OR EVEN DUE SOUTH. GIANT HAIL...PERHAPS GREATER
THAN BASEBALLS WILL BE POSSIBLE WITH ANY SUPERCELL STORM.
SURFACE TEMPS WILL LIKELY REACH 105 WEST OF OUR CWA BEHIND THE
DRY LINE...WHICH SHOULD ALLOW A THERMAL SURFACE LOW TO INTENSIFY
TODAY. THIS WILL CAUSE LOW LEVEL WINDS TO BACK OVER THE NORTHERN
PART OF THE CWA...WHICH WILL ENHANCE LOW LEVEL DIRECTION SHEAR
PROFILES ACROSS THE NORTHWEST CWA DESPITE WIND SPEEDS REMAINING
FAIRLY WEAK AND LESS THAN 15KT AT ANY GIVEN LEVEL. STORM RELATIVE
0-3KM HELICITY VALUES BY THE RUC/NAM ARE FORECAST TO BE NEAR
100-150 MS/S2...SIGNIFICANTLY LESS THAN LAST WEDNESDAY...BUT AGAIN
THE HIGHER INSTABILITY CAN OFTEN COMPENSATE TO RAISE THE CONCERN
FOR TORNADOGENESIS. IN ADDITION SHOULD SUPERCELLS IN FACT MOVE
SOUTH...THESE MODEL VALUES OF 0-3 SRH VALUES ARE TOO LOW. HAVE
ADDED A RISK OF ISOLATED TORNADOES TO THE HWO AND GRAPHIC
FORECASTS AS WELL.
I SHOULD STRESS ALL OF THE SEVERE THREAT TODAY IS CONDITIONAL
BASED ON THE CAP BREAKING...WHICH AGAIN IS NOT GUARANTEED BUT IS
PROBABLE. WITH LESS HEATING ACROSS THE I-35 CORRIDOR...THIS SHOULD
KEEP SEVERE CONVECTION CONFINED TO THE WESTERN ZONES WITH THE CAP
TOO STRONG FOR SURFACE BASED CONVECTION IN THE CENTRAL AND EASTERN
ZONES. STILL IT IS POSSIBLE RESIDUAL ELEVATED CONVECTION OR ANVIL
PRECIPITATION MAY ENTER THE CENTRAL ZONES LATE TONIGHT...BUT WILL
KEEP POPS AT 10 PERCENT WITH NO MODEL SUPPORT FOR THIS SCENARIO.
FOR THE UPDATE HAVE LOWERED HIGHS IN THE SOUTHEAST ZONES DUE TO
MORNING RAIN AND CLOUDS. HAVE RAISED POPS IN THE WESTERN ZONES TO
REFLECT THE HIGHER POTENTIAL FOR STORMS THIS AFTERNOON AND EVENING.
TR.92
&&
.PREV DISCUSSION... /ISSUED 354 AM CDT FRI MAY 17 2013/
...A FEW SEVERE STORMS POSSIBLE ACROSS FAR WESTERN NORTH TEXAS BY
EACH EVENING TODAY AND SATURDAY...THEN NORTH OF I-20 LATE SUNDAY...
WEATHER FORECAST REMAINS CHALLENGING TODAY INTO THE WEEKEND. WE
CONTINUED TO SEE A SUBTLE SURFACE BOUNDARY SITUATED ALONG/NORTH OF
HWY 38 THIS MORNING AS EVIDENCED BY THE BACKED/LIGHTER EAST WINDS
AND LOWER SURFACE DEW POINTS THIS MORNING...WHILE STRONGER SSE
WINDS 10 TO 15 MPH WHERE OCCURRING FROM THE I-20 CORRIDOR INTO
CENTRAL TEXAS. SOME PATCHY DENSE FOG WAS OCCURRING ALONG THE RED
RIVER VALLEY...WHILE A SUBTLE DISTURBANCE WAS MOVING ACROSS WITHIN
THE UPPER RIDGE OVER THE TOP OF THE AREA. SOME AC/ACCAS WAS NOTED
ON INFRARED SATELLITE IMAGERY WITH STEEP LAPSE RATES ALOFT ON THE
00Z FWD SOUNDING AND MODELS. ISOLATED...ELEVATED/HIGH-BASED
SHOWERS AND STORMS ARE POSSIBLE THIS MORNING MAINLY ALONG AND
SOUTH OF THE I-20/I-30 CORRIDORS. LIGHTNING WILL BE THE MAIN
THREAT WITH ACTIVITY THIS MORNING WITH VERY LITTLE IN THE WAY OF
MEASURABLE RAINFALL EXPECTED.
THE SURFACE DRYLINE AND ASSOCIATED LOW PRESSURE OVER FAR WEST
TEXAS WILL CONTINUE TO DEEPEN AND SLIDE SLOWLY EAST TOWARD OUR FAR
W/SW COUNTIES LATE THIS AFTERNOON/EVE. STRONG MIXING AND HEATING
ALONG AND JUST AHEAD OF THIS FEATURE WILL HELP HIGHS SOAR WELL
INTO THE 90S WITH A FEW AREAS TOPPING THE CENTURY MARK WEST OF
I-35/I-35W. OUR CAPPING INVERSION WAS ELEVATED AND BASED ABOVE
800MB AND NOT OVERLY STOUT...SO DESPITE THE UPPER RIDGE ARRIVING
OVERHEAD...FEEL THE HOT TEMPS WILL MAKE IT BREAKABLE. HIGH-RES
WRF/ARW/AND HRRR MODELS ALL HINT AT ISOLATED STORM DEVELOPMENT JUST
W/SW OF OUR CWA AT PEAK HEATING AND POTENTIALLY AFFECTING OUR FAR
WSW COUNTIES BETWEEN 4 PM AND SUNSET. INSTABILITY WILL BE VERY HIGH
WITH MODELS SHOWING 3500-5000 J/KG SBCAPE OR POSSIBLY MORE WITH
VERY STEEP MID LEVEL LAPSE RATES OVER 8 DEG C/KM. ANY ISOLATED
STORMS THAT OCCUR WILL LIKELY BE SEVERE WITH VERY LARGE HAIL AND
DAMAGING DOWNBURSTS. DESPITE SURFACE DEW POINTS BEING NEAR 70
DEGREES...THE HOT TEMPERATURES WILL RESULT IN RELATIVELY HIGH
BASES AND A LOWER TORNADO THREAT THAN A FEW DAYS AGO. WITH THE
UPPER RIDGE OVERHEAD...STORMS WILL DIMINISH IN STRENGTH OR
DISSIPATE RAPIDLY AROUND SUNSET WITH LOSS OF HEATING AND THE CAP
INTENSIFYING QUICKLY BY LATE EVENING.
THE UPPER RIDGE SHIFTS EAST OF THE AREA ON SATURDAY WITH LONGWAVE
UPPER TROUGH SNAKING OVER THE ROCKIES INTO THE WESTERN HIGH
PLAINS. THE DRYLINE WILL ACTUALLY MAKE A STRONGER PUSH TOWARD OUR
FAR WESTERN COUNTIES BY EARLY EVENING SATURDAY WITH A LITTLE
BETTER UPPER SUPPORT. INSTABILITY WILL BE VERY STRONG ONCE AGAIN
WITH ISOLATED TO SCATTERED STRONG TO SEVERE STORMS EXPECTED MAINLY
ALONG AND WEST OF HWY 281...THEN DIMINISHING QUICKLY AFTER SUNSET
WITH THE CAP INTENSIFYING ONCE AGAIN. THE UPPER TROUGH DAMPENS
OVER THE CONUS ON SUNDAY WITH STRONG WESTERLY FLOW ALOFT OCCURRING
FROM THE RED RIVER VALLEY NORTH THROUGH THE CENTRAL PLAINS. HAVE
MODIFIED BEST CHANCES TO OCCUR NORTH OF I-20 AND INTO THE RED
RIVER VALLEY...WITH THE CAP BEING MUCH STRONGER OVER THE SOUTH.
DIURNAL SEVERE WEATHER WILL BE POSSIBLE AGAIN...BUT CONFIDENCE IS
LOWER FOR LATE SUNDAY DUE TO UNCERTAINTIES REGARDING CAP STRENGTH
AND SOUTHERN EXTENT OF FORCING. THE BEST SURFACE FOCUS WILL BE
ALONG A COLD FRONT THAT IS EXPECTED TO BE WELL TO THE NORTHWEST OF
THE AREA AS WELL.
OTHERWISE IN THE EXTENDED...STAYED WITH PERSISTENCE WITH THE
PREVIOUS FORECAST WITH LOW POPS RETURNING BY MID WEEK WITH A COLD
FRONT WEAKENING AND STALLING ACROSS THE NORTHWEST COUNTIES. A
SHORTWAVE TROUGH WILL BE MOVING OVER THE CENTRAL AND SOUTHERN
PLAINS AT THIS TIME AS WELL. IT IS TOO EARLY TO ASSESS ANY SEVERE
WEATHER THREAT THIS FAR OUT...BUT WILL CONTINUE TO ASSESS THESE
POSSIBILITIES IN THE COMING DAYS AHEAD. 05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 89 72 93 72 88 / 10 10 5 10 10
WACO, TX 91 71 92 71 90 / 10 10 5 10 10
PARIS, TX 82 68 86 69 86 / 10 10 10 10 10
DENTON, TX 86 70 93 71 89 / 10 10 10 10 20
MCKINNEY, TX 84 69 91 69 88 / 10 10 5 10 10
DALLAS, TX 88 72 93 72 90 / 10 10 5 10 10
TERRELL, TX 87 69 90 70 89 / 10 10 5 10 10
CORSICANA, TX 89 70 91 70 89 / 40 10 5 10 10
TEMPLE, TX 91 70 91 71 89 / 10 20 10 10 10
MINERAL WELLS, TX 94 70 96 70 93 / 10 20 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
000
FXUS64 KFWD 171535
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1035 AM CDT FRI MAY 17 2013
.UPDATE...
12Z FWD SOUNDING DEPICTS NEARLY DRY ADIABATIC LAPSE RATES FROM
850MB UP TO 500MB. CURRENTLY A WEAK SHORTWAVE WAS MOVING ACROSS
NORTH TEXAS IN NORTHWEST FLOW ALOFT AND WAS RESPONSIBLE FOR THE
ELEVATED CONVECTION OCCURRING OVER THE SOUTHEAST ZONES THIS
MORNING. THESE STORMS HAVE PRODUCED HAIL UP TO GOLF BALL SIZE AND
ARE A TESTAMENT TO THE STEEP LAPSE RATES ALOFT. THIS SHORTWAVE
WILL CONTINUE TO MOVE SOUTHEAST AND OUT OF THE AREA BY MIDDAY.
STRONG SURFACE HEATING ACROSS THE WESTERN ZONES WILL HELP PUSH
TEMPERATURES TO NEAR THE CENTURY MARK THIS AFTERNOON. A DRY LINE
WILL REACH A LINE FROM GRAHAM TO COMANCHE TO LLANO. SHORT TERM
MODELS DEPICT DEWPOINTS IN THE LOW TO MID 70S AHEAD OF THE DRY
LINE...BUT THIS IS PROBABLY TOO HIGH. BELIEVE DEWPOINTS WILL MIX
OUT INTO THE UPPER 60S. NONETHELESS...THIS WILL CONTRIBUTE TO
EXTREME INSTABILITY WITH SURFACE BASED CAPE VALUES ABOVE 4000
J/KG. UNLIKE THE EVENT ON WEDNESDAY...THE CAP WILL BE MUCH
STRONGER TODAY AND WILL REQUIRE STRONG HEATING AND THE MESOSCALE
FORCING PROVIDED BY A DRY LINE TO BE OVERCOME. GIVEN A REASONABLE
FORECAST TEMP/DEWPOINT COMBINATION OF 99 OVER 68 AHEAD OF THE DRY
LINE...THIS SHOULD BE SUFFICIENT FOR THE CAP TO BREAK.
SEVERAL OF THE HI-RES CONVECTION ALLOWING MODELS AND THE LAST 2
RUNS OF THE NAM ARE SHOWING STORM INITIATION LATE THIS
AFTERNOON...AND ARE FOCUSING IN ON THE AREA NEAR THE LLANO
UPLIFT...WHICH WOULD AFFECT OUR SW ZONES AND ALSO ANOTHER AREA
NEAR GRAHAM AND BRECKENRIDGE. DEEP LAYER SHEAR IS NOT OVERLY
STRONG AND IS ON THE LOW END OF THE ALLOWABLE LEVEL FOR
SUPERCELLS. HOWEVER THE HIGH INSTABILITY WILL LIKELY COMPENSATE
AND ALLOW FOR SUPERCELL MODES. SUPERCELL STORM MOTION TECHNIQUES
BASED ONLY ON WIND PROFILES ARE EAST AT 10KT...BUT IN CASES OF
HIGH INSTABILITY AND WEAK FLOW...THESE SUPERCELLS WILL LIKELY HEAD
SLOWLY SOUTHEAST OR EVEN DUE SOUTH. GIANT HAIL...PERHAPS GREATER
THAN BASEBALLS WILL BE POSSIBLE WITH ANY SUPERCELL STORM.
SURFACE TEMPS WILL LIKELY REACH 105 WEST OF OUR CWA BEHIND THE
DRY LINE...WHICH SHOULD ALLOW A THERMAL SURFACE LOW TO INTENSIFY
TODAY. THIS WILL CAUSE LOW LEVEL WINDS TO BACK OVER THE NORTHERN
PART OF THE CWA...WHICH WILL ENHANCE LOW LEVEL DIRECTION SHEAR
PROFILES ACROSS THE NORTHWEST CWA DESPITE WIND SPEEDS REMAINING
FAIRLY WEAK AND LESS THAN 15KT AT ANY GIVEN LEVEL. STORM RELATIVE
0-3KM HELICITY VALUES BY THE RUC/NAM ARE FORECAST TO BE NEAR
100-150 MS/S2...SIGNIFICANTLY LESS THAN LAST WEDNESDAY...BUT AGAIN
THE HIGHER INSTABILITY CAN OFTEN COMPENSATE TO RAISE THE CONCERN
FOR TORNADOGENESIS. IN ADDITION SHOULD SUPERCELLS IN FACT MOVE
SOUTH...THESE MODEL VALUES OF 0-3 SRH VALUES ARE TOO LOW. HAVE
ADDED A RISK OF ISOLATED TORNADOES TO THE HWO AND GRAPHIC
FORECASTS AS WELL.
I SHOULD STRESS ALL OF THE SEVERE THREAT TODAY IS CONDITIONAL
BASED ON THE CAP BREAKING...WHICH AGAIN IS NOT GARAUNTEED BUT IS
PROBABLE. WITH LESS HEATING ACROSS THE I-35 CORRIDOR...THIS SHOULD
KEEP SEVERE CONVECTION CONFINED TO THE WESTERN ZONES WITH THE CAP
TOO STRONG FOR SURFACE BASED CONVECTION IN THE CENTRAL AND EASTERN
ZONES. STILL IT IS POSSIBLE RESIDUAL ELEVATED CONVECTION OR ANVIL
PRECIPITATION MAY ENTER THE CENTRAL ZONES LATE TONIGHT...BUT WILL
KEEP POPS AT 10 PERCENT WITH NO MODEL SUPPORT FOR THIS SCENARIO.
FOR THE UPDATE HAVE LOWERED HIGHS IN THE SOUTHEAST ZONES DUE TO
MORNING RAIN AND CLOUDS. HAVE RAISED POPS IN THE WESTERN ZONES TO
REFLECT THE HIGHER POTENTIAL FOR STORMS THIS AFTERNOON AND EVENING.
TR.92
&&
.PREV DISCUSSION... /ISSUED 354 AM CDT FRI MAY 17 2013/
...A FEW SEVERE STORMS POSSIBLE ACROSS FAR WESTERN NORTH TEXAS BY
EACH EVENING TODAY AND SATURDAY...THEN NORTH OF I-20 LATE SUNDAY...
WEATHER FORECAST REMAINS CHALLENGING TODAY INTO THE WEEKEND. WE
CONTINUED TO SEE A SUBTLE SURFACE BOUNDARY SITUATED ALONG/NORTH OF
HWY 38 THIS MORNING AS EVIDENCED BY THE BACKED/LIGHTER EAST WINDS
AND LOWER SURFACE DEW POINTS THIS MORNING...WHILE STRONGER SSE
WINDS 10 TO 15 MPH WHERE OCCURRING FROM THE I-20 CORRIDOR INTO
CENTRAL TEXAS. SOME PATCHY DENSE FOG WAS OCCURRING ALONG THE RED
RIVER VALLEY...WHILE A SUBTLE DISTURBANCE WAS MOVING ACROSS WITHIN
THE UPPER RIDGE OVER THE TOP OF THE AREA. SOME AC/ACCAS WAS NOTED
ON INFRARED SATELLITE IMAGERY WITH STEEP LAPSE RATES ALOFT ON THE
00Z FWD SOUNDING AND MODELS. ISOLATED...ELEVATED/HIGH-BASED
SHOWERS AND STORMS ARE POSSIBLE THIS MORNING MAINLY ALONG AND
SOUTH OF THE I-20/I-30 CORRIDORS. LIGHTNING WILL BE THE MAIN
THREAT WITH ACTIVITY THIS MORNING WITH VERY LITTLE IN THE WAY OF
MEASURABLE RAINFALL EXPECTED.
THE SURFACE DRYLINE AND ASSOCIATED LOW PRESSURE OVER FAR WEST
TEXAS WILL CONTINUE TO DEEPEN AND SLIDE SLOWLY EAST TOWARD OUR FAR
W/SW COUNTIES LATE THIS AFTERNOON/EVE. STRONG MIXING AND HEATING
ALONG AND JUST AHEAD OF THIS FEATURE WILL HELP HIGHS SOAR WELL
INTO THE 90S WITH A FEW AREAS TOPPING THE CENTURY MARK WEST OF
I-35/I-35W. OUR CAPPING INVERSION WAS ELEVATED AND BASED ABOVE
800MB AND NOT OVERLY STOUT...SO DESPITE THE UPPER RIDGE ARRIVING
OVERHEAD...FEEL THE HOT TEMPS WILL MAKE IT BREAKABLE. HIGH-RES
WRF/ARW/AND HRRR MODELS ALL HINT AT ISOLATED STORM DEVELOPMENT JUST
W/SW OF OUR CWA AT PEAK HEATING AND POTENTIALLY AFFECTING OUR FAR
WSW COUNTIES BETWEEN 4 PM AND SUNSET. INSTABILITY WILL BE VERY HIGH
WITH MODELS SHOWING 3500-5000 J/KG SBCAPE OR POSSIBLY MORE WITH
VERY STEEP MID LEVEL LAPSE RATES OVER 8 DEG C/KM. ANY ISOLATED
STORMS THAT OCCUR WILL LIKELY BE SEVERE WITH VERY LARGE HAIL AND
DAMAGING DOWNBURSTS. DESPITE SURFACE DEW POINTS BEING NEAR 70
DEGREES...THE HOT TEMPERATURES WILL RESULT IN RELATIVELY HIGH
BASES AND A LOWER TORNADO THREAT THAN A FEW DAYS AGO. WITH THE
UPPER RIDGE OVERHEAD...STORMS WILL DIMINISH IN STRENGTH OR
DISSIPATE RAPIDLY AROUND SUNSET WITH LOSS OF HEATING AND THE CAP
INTENSIFYING QUICKLY BY LATE EVENING.
THE UPPER RIDGE SHIFTS EAST OF THE AREA ON SATURDAY WITH LONGWAVE
UPPER TROUGH SNAKING OVER THE ROCKIES INTO THE WESTERN HIGH
PLAINS. THE DRYLINE WILL ACTUALLY MAKE A STRONGER PUSH TOWARD OUR
FAR WESTERN COUNTIES BY EARLY EVENING SATURDAY WITH A LITTLE
BETTER UPPER SUPPORT. INSTABILITY WILL BE VERY STRONG ONCE AGAIN
WITH ISOLATED TO SCATTERED STRONG TO SEVERE STORMS EXPECTED MAINLY
ALONG AND WEST OF HWY 281...THEN DIMINISHING QUICKLY AFTER SUNSET
WITH THE CAP INTENSIFYING ONCE AGAIN. THE UPPER TROUGH DAMPENS
OVER THE CONUS ON SUNDAY WITH STRONG WESTERLY FLOW ALOFT OCCURRING
FROM THE RED RIVER VALLEY NORTH THROUGH THE CENTRAL PLAINS. HAVE
MODIFIED BEST CHANCES TO OCCUR NORTH OF I-20 AND INTO THE RED
RIVER VALLEY...WITH THE CAP BEING MUCH STRONGER OVER THE SOUTH.
DIURNAL SEVERE WEATHER WILL BE POSSIBLE AGAIN...BUT CONFIDENCE IS
LOWER FOR LATE SUNDAY DUE TO UNCERTAINTIES REGARDING CAP STRENGTH
AND SOUTHERN EXTENT OF FORCING. THE BEST SURFACE FOCUS WILL BE
ALONG A COLD FRONT THAT IS EXPECTED TO BE WELL TO THE NORTHWEST OF
THE AREA AS WELL.
OTHERWISE IN THE EXTENDED...STAYED WITH PERSISTENCE WITH THE
PREVIOUS FORECAST WITH LOW POPS RETURNING BY MID WEEK WITH A COLD
FRONT WEAKENING AND STALLING ACROSS THE NORTHWEST COUNTIES. A
SHORTWAVE TROUGH WILL BE MOVING OVER THE CENTRAL AND SOUTHERN
PLAINS AT THIS TIME AS WELL. IT IS TOO EARLY TO ASSESS ANY SEVERE
WEATHER THREAT THIS FAR OUT...BUT WILL CONTINUE TO ASSESS THESE
POSSIBILITIES IN THE COMING DAYS AHEAD.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 89 72 93 72 88 / 10 10 5 10 10
WACO, TX 91 71 92 71 90 / 10 10 5 10 10
PARIS, TX 82 68 86 69 86 / 10 10 10 10 10
DENTON, TX 86 70 93 71 89 / 10 10 10 10 20
MCKINNEY, TX 84 69 91 69 88 / 10 10 5 10 10
DALLAS, TX 88 72 93 72 90 / 10 10 5 10 10
TERRELL, TX 87 69 90 70 89 / 10 10 5 10 10
CORSICANA, TX 89 70 91 70 89 / 40 10 5 10 10
TEMPLE, TX 91 70 91 71 89 / 10 20 10 10 10
MINERAL WELLS, TX 94 70 96 70 93 / 10 20 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
000
FXUS64 KFWD 170854
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
354 AM CDT FRI MAY 17 2013
.DISCUSSION...
...A FEW SEVERE STORMS POSSIBLE ACROSS FAR WESTERN NORTH TEXAS BY
EACH EVENING TODAY AND SATURDAY...THEN NORTH OF I-20 LATE SUNDAY...
WEATHER FORECAST REMAINS CHALLENGING TODAY INTO THE WEEKEND. WE
CONTINUED TO SEE A SUBTLE SURFACE BOUNDARY SITUATED ALONG/NORTH OF
HWY 38 THIS MORNING AS EVIDENCED BY THE BACKED/LIGHTER EAST WINDS
AND LOWER SURFACE DEW POINTS THIS MORNING...WHILE STRONGER SSE
WINDS 10 TO 15 MPH WHERE OCCURRING FROM THE I-20 CORRIDOR INTO
CENTRAL TEXAS. SOME PATCHY DENSE FOG WAS OCCURRING ALONG THE RED
RIVER VALLEY...WHILE A SUBTLE DISTURBANCE WAS MOVING ACROSS WITHIN
THE UPPER RIDGE OVER THE TOP OF THE AREA. SOME AC/ACCAS WAS NOTED
ON INFRARED SATELLITE IMAGERY WITH STEEP LAPSE RATES ALOFT ON THE
00Z FWD SOUNDING AND MODELS. ISOLATED...ELEVATED/HIGH-BASED
SHOWERS AND STORMS ARE POSSIBLE THIS MORNING MAINLY ALONG AND
SOUTH OF THE I-20/I-30 CORRIDORS. LIGHTNING WILL BE THE MAIN
THREAT WITH ACTIVITY THIS MORNING WITH VERY LITTLE IN THE WAY OF
MEASURABLE RAINFALL EXPECTED.
THE SURFACE DRYLINE AND ASSOCIATED LOW PRESSURE OVER FAR WEST
TEXAS WILL CONTINUE TO DEEPEN AND SLIDE SLOWLY EAST TOWARD OUR FAR
W/SW COUNTIES LATE THIS AFTERNOON/EVE. STRONG MIXING AND HEATING
ALONG AND JUST AHEAD OF THIS FEATURE WILL HELP HIGHS SOAR WELL
INTO THE 90S WITH A FEW AREAS TOPPING THE CENTURY MARK WEST OF
I-35/I-35W. OUR CAPPING INVERSION WAS ELEVATED AND BASED ABOVE
800MB AND NOT OVERLY STOUT...SO DESPITE THE UPPER RIDGE ARRIVING
OVERHEAD...FEEL THE HOT TEMPS WILL MAKE IT BREAKABLE. HIGH-RES
WRF/ARW/AND HRRR MODELS ALL HINT AT ISOLATED STORM DEVELOPMENT JUST
W/SW OF OUR CWA AT PEAK HEATING AND POTENTIALLY AFFECTING OUR FAR
WSW COUNTIES BETWEEN 4 PM AND SUNSET. INSTABILITY WILL BE VERY HIGH
WITH MODELS SHOWING 3500-5000 J/KG SBCAPE OR POSSIBLY MORE WITH
VERY STEEP MID LEVEL LAPSE RATES OVER 8 DEG C/KM. ANY ISOLATED
STORMS THAT OCCUR WILL LIKELY BE SEVERE WITH VERY LARGE HAIL AND
DAMAGING DOWNBURSTS. DESPITE SURFACE DEW POINTS BEING NEAR 70
DEGREES...THE HOT TEMPERATURES WILL RESULT IN RELATIVELY HIGH
BASES AND A LOWER TORNADO THREAT THAN A FEW DAYS AGO. WITH THE
UPPER RIDGE OVERHEAD...STORMS WILL DIMINISH IN STRENGTH OR
DISSIPATE RAPIDLY AROUND SUNSET WITH LOSS OF HEATING AND THE CAP
INTENSIFYING QUICKLY BY LATE EVENING.
THE UPPER RIDGE SHIFTS EAST OF THE AREA ON SATURDAY WITH LONGWAVE
UPPER TROUGH SNAKING OVER THE ROCKIES INTO THE WESTERN HIGH
PLAINS. THE DRYLINE WILL ACTUALLY MAKE A STRONGER PUSH TOWARD OUR
FAR WESTERN COUNTIES BY EARLY EVENING SATURDAY WITH A LITTLE
BETTER UPPER SUPPORT. INSTABILITY WILL BE VERY STRONG ONCE AGAIN
WITH ISOLATED TO SCATTERED STRONG TO SEVERE STORMS EXPECTED MAINLY
ALONG AND WEST OF HWY 281...THEN DIMINISHING QUICKLY AFTER SUNSET
WITH THE CAP INTENSIFYING ONCE AGAIN. THE UPPER TROUGH DAMPENS
OVER THE CONUS ON SUNDAY WITH STRONG WESTERLY FLOW ALOFT OCCURRING
FROM THE RED RIVER VALLEY NORTH THROUGH THE CENTRAL PLAINS. HAVE
MODIFIED BEST CHANCES TO OCCUR NORTH OF I-20 AND INTO THE RED
RIVER VALLEY...WITH THE CAP BEING MUCH STRONGER OVER THE SOUTH.
DIURNAL SEVERE WEATHER WILL BE POSSIBLE AGAIN...BUT CONFIDENCE IS
LOWER FOR LATE SUNDAY DUE TO UNCERTAINTIES REGARDING CAP STRENGTH
AND SOUTHERN EXTENT OF FORCING. THE BEST SURFACE FOCUS WILL BE
ALONG A COLD FRONT THAT IS EXPECTED TO BE WELL TO THE NORTHWEST OF
THE AREA AS WELL.
OTHERWISE IN THE EXTENDED...STAYED WITH PERSISTENCE WITH THE
PREVIOUS FORECAST WITH LOW POPS RETURNING BY MID WEEK WITH A COLD
FRONT WEAKENING AND STALLING ACROSS THE NORTHWEST COUNTIES. A
SHORTWAVE TROUGH WILL BE MOVING OVER THE CENTRAL AND SOUTHERN
PLAINS AT THIS TIME AS WELL. IT IS TOO EARLY TO ASSESS ANY SEVERE
WEATHER THREAT THIS FAR OUT...BUT WILL CONTINUE TO ASSESS THESE
POSSIBILITIES IN THE COMING DAYS AHEAD.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 89 72 93 72 88 / 10 10 5 10 10
WACO, TX 92 71 92 71 90 / 20 10 5 10 10
PARIS, TX 82 68 86 69 86 / 10 10 10 10 10
DENTON, TX 86 70 93 71 89 / 10 10 10 10 20
MCKINNEY, TX 84 69 91 69 88 / 10 10 5 10 10
DALLAS, TX 88 72 93 72 90 / 10 10 5 10 10
TERRELL, TX 89 69 90 70 89 / 10 10 5 10 10
CORSICANA, TX 91 70 91 70 89 / 20 10 5 10 10
TEMPLE, TX 91 70 91 71 89 / 10 10 10 10 10
MINERAL WELLS, TX 94 70 96 70 93 / 10 10 10 10 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/
000
FXUS64 KFWD 170436
AFDFWD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1136 PM CDT THU MAY 16 2013
.AVIATION...
COOLER AIR AND LIGHT NORTHEAST WINDS RESIDE NORTH OF A SUBTLE
SURFACE TROUGH CURRENTLY SITUATED JUST NORTH OF THE DALLAS-FORT
WORTH METROPLEX...LEADING TO IFR CIGS AND PATCHY FOG OVER AREAS
NEAR THE RED RIVER. WILL NEED TO KEEP AN EYE ON THIS AREA...BUT
FEEL THE BOUNDARY WILL LIFT NORTH WHILE WASHING OUT OVERNIGHT PER
THE LATEST GUIDANCE. THIS SHOULD PRECLUDE A SIGNIFICANT REDUCTION
IN VISIBILITIES IN THE METRO AREA. MEANWHILE A SWATH OF MVFR
STRATUS OVER CENTRAL AND SOUTHEAST TEXAS CAN BE SEEN ON SATELLITE
ADVANCING NORTH. THESE CLOUDS WILL REACH KACT SHORTLY AND SHOULD
MAKE IT UP TO THE DALLAS-FORT WORTH AREA AROUND 08-09Z. WILL STICK
WITH THE 010 FROM THE PREVIOUS FORECASTS...BUT KEEP AN EYE ON
TRENDS PRIOR TO THE CLOUD DECK SPREADING OVERHEAD. THERE WILL ALSO
LIKELY BE SOME FOG AT ALL AREAS WHICH COULD REDUCE SURFACE
VISIBILITIES TO AROUND 3 MILES DURING THE EARLY MORNING HOURS.
CONDITIONS SHOULD IMPROVE MID TO LATE MORNING WITH VFR CONDITIONS
EXPECTED DURING THE AFTERNOON HOURS FRIDAY. OTHERWISE SOUTH TO
SOUTHEAST WINDS AROUND 10 KT CAN BE EXPECTED.
30
&&
.PREV DISCUSSION... /ISSUED 259 PM CDT THU MAY 16 2013/
UPPER LOW IS CURRENTLY LEAVING EASTERN OKLAHOMA HEADING FOR THE
MISSOURI BOOT HEEL. LARGE SCALE LIFT ASSOCIATED WITH THE LOW IS
ALSO HEADING EAST AND THE NORTHEAST RAIN HAS MOVED INTO EAST TX.
WITH WESTERLY FLOW ALOFT...CLEAR SKIES...AND THE DRY LINE SITTING
ACROSS THE BIG COUNTRY...HAVE ADDED A SMALL AREA OF ISOLATED
THUNDER ACROSS FAR SOUTHWEST ZONES. HI RES MODELS SHOW A WEAK
SHORT WAVE IN THE FLOW TO ADD A BIT OF LIFT...ALTHOUGH VERY
LITTLE CU HAS DEVELOPED DOWN THERE SO FAR.
WARM MOIST AIR MASS WILL PERSIST ACROSS NORTH TEXAS...WITH DRY
LINE STORMS EXPECTED SATURDAY EVENING IN THE NORTHWEST...AND
SUNDAY EVENING IN THE NORTHWEST POSSIBLY DRIFTING EAST INTO THE
I-35 CORRIDOR IN RESPONSE TO AN UPPER LOW MOVING INTO THE
CENTRAL AND NORTHERN PLAINS.
AS THE NEW UPPER LOW ENTERS THE NORTHERN PLAINS SUNDAY AND
PERSISTS UNTIL WEDNESDAY...NORTH TEXAS WILL REMAIN IN SOUTHWEST
FLOW ALOFT. THIS IS A BIT MORE FAVORABLE FOR RAIN CHANCES AS
DISTURBANCES ROTATE AROUND THE LOW AND THE DRY LINE PUSHES EAST
TOWARDS NORTH TEXAS EACH DAY. HAVE KEPT LOW POPS IN THE FORECAST
NEXT WEEK TO COVER THIS PATTERN. THE FLOW BECOMES MORE ZONAL
THROUGH FRIDAY MORNING AND MODELS CONTINUE TO PRODUCE
INTERMITTENT RAIN CHANCES SO LOW POPS CONTINUE THROUGH THE END OF
THIS FORECAST. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 70 86 71 90 70 / 10 5 10 10 10
WACO, TX 71 92 71 91 70 / 10 10 5 10 10
PARIS, TX 67 81 69 86 69 / 10 10 10 10 10
DENTON, TX 69 84 70 91 70 / 10 5 10 10 10
MCKINNEY, TX 68 84 69 89 69 / 10 10 10 10 10
DALLAS, TX 70 89 71 92 70 / 10 5 10 10 10
TERRELL, TX 69 89 69 90 69 / 10 10 10 10 10
CORSICANA, TX 70 91 70 90 70 / 10 5 5 10 10
TEMPLE, TX 71 91 70 90 69 / 10 10 5 10 10
MINERAL WELLS, TX 69 92 70 94 69 / 10 5 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/69
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