189 
FXUS64 KFWD 102326 AAA
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
626 PM CDT SUN JUN 10 2012

.AVIATION...
CONCERNS...POSSIBLE MVFR CEILINGS MONDAY MORNING.

SOUTHERLY WINDS OF AROUND 15 KNOTS WILL PREVAIL OVERNIGHT. MVFR
STRATUS IS EXPECTED TO DEVELOP ACROSS SOUTH TEXAS TONIGHT AND
SPREAD NORTH INTO THE WACO AREA AROUND 09Z...AND INTO THE
METROPLEX AROUND 11Z. CONDITIONS ARE EXPECTED TO RETURN TO VFR
17-18Z MONDAY. A COLD FRONT CURRENTLY /AS OF 23Z/ EXTENDS FROM
SOUTHEASTERN NEBRASKA TO SOUTH OF GAGE OKLAHOMA /KGAG/ TO
NORTHEASTERN NEW MEXICO NORTH OF TUCUMCARI /KTCC/. THIS FRONT
WILL MOVE SOUTHEAST THROUGH MONDAY AND EXTEND SOUTH OF AN ADA
OKLAHOMA /KADA/...WICHITA FALLS /KSPS/....SWEETWATER /KSWW/ LINE
BY 00Z TUESDAY. EXPECT SOUTHERLY WINDS TO CONTINUE ACROSS THE
REGION THROUGH THE FORECAST PERIOD. THERE WILL BE A CHANCE OF
THUNDERSTORMS ALONG THE FRONT MONDAY...BUT THE AIR MASS ACROSS
NORTH TEXAS WILL REMAIN CAPPED THROUGH 00Z...AND THE CHANCES AT
THE METROPLEX TAF SITES AFTER 00Z ARE TOO LOW TO INCLUDE IN THE
TAFS AT THIS TIME.
 



58

&&


.PREV DISCUSSION... /ISSUED 403 PM CDT SUN JUN 10 2012/

19Z SURFACE OBSERVATIONS INDICATED A COLD FRONT THROUGH THE SOUTHERN
HIGH PLAINS AND LOCATED JUST TO THE NORTH OF AMARILLO. A DRYLINE
WAS OBSERVED FROM JUST EAST OF CHILDRESS SOUTH TOWARDS SAN ANGELO
AND THEN ANGLING BACK SOUTHWEST TOWARDS FORT STOCKTON. SOUTH-
SOUTHEASTERLY FLOW WAS IN PLACE ACROSS MUCH OF NORTH TEXAS WITH
UPPER 60S TO LOWER 70S DEW POINTS HOLDING JUST SOUTH OF INTERSTATE
20 EARLY THIS AFTERNOON. VISIBLE SATELLITE INDICATED VERY LITTLE
COVERAGE OF CUMULUS CLOUDS OVER THE FORECAST AREA BUT DID DEPICT A
LARGE PLUME OF SMOKE OVER NORTH TX ABOVE THE 15000 FT LEVEL FROM
WILDFIRE ACTIVITY IN NEW MEXICO THE PAST COUPLE OF DAYS. 12Z UPPER
AIR ANALYSIS INDICATED SHORTWAVE RIDGING MOVING OVER NORTH TX WITH
A PLUME OF VERY STEEP MID-LEVEL LAPSE RATES ORIENTED DIRECTLY
BENEATH AND WEST OF THE RIDGE AXIS. H700 TO H500 OBSERVED
TEMPERATURE DIFFERENCES IN EXCESS OF 24 DEG C WERE OBSERVED OVER
ALL OF THE SOUTHERN HIGH PLAINS. A LARGE UPPER LEVEL TROUGH WAS
LOCATED OVER CENTRAL MT AND WY THIS MORNING WITH THE JET STREAM
LOCATED IN THE BASE OF THE TROUGH SPILLING OVER THE CENTRAL CONUS
ROCKIES AND OVER THE NORTHERN PLAINS.

THIS AFTERNOON THROUGH MONDAY...THE STRONG ELEVATED MIXED LAYER
(EML) LOCATED BENEATH AND WEST OF THE RIDGE ALOFT SHOULD HAVE
MOVED ON TOP OF NORTH TX BY THE TIME OF THIS DISCUSSION. THIS WILL
KEEP A STRONG CAPPING INVERSION IN PLACE OVER NORTH TX THROUGH
AT LEAST MONDAY AFTERNOON. FORCING FOR SUBSIDENCE ASSOCIATED WITH
THE RIDGE ALOFT SHOULD HELP STRENGTHEN THIS CAP THROUGH THE
PERIOD...AND AS A RESULT HAVE MAINTAINED A DRY FORECAST AT THIS
TIME. UPPER 60S AND LOWER 70S DEW POINTS BENEATH THE EML HAVE
BROUGHT MIXED LAYER AND SURFACE BASED CONVECTIVE POTENTIAL ENERGY
VALUES UP INTO THE 3000 TO 4000 J/KG RANGE SOUTH OF INTERSTATE 20.
WHILE THIS POTENTIAL ENERGY IS NOT EXPECTED TO BE CONVERTED INTO
BUOYANT ENERGY DUE TO THE EML CAP AND SUBSIDENCE OVER NORTH
TX...HIGH RESOLUTION GUIDANCE AND THE OPERATIONAL NAM ARE
INDICATING THAT A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS MAY
DEVELOP ALONG THE DRYLINE SOUTHWEST OF THE CWA BY SUNSET. OUTFLOW
FROM THIS CONVECTION MAY MOVE NORTHEAST AND PROVIDE SOME LIFT OVER
SOUTHWEST PORTIONS OF THE CWA THIS EVENING...HOWEVER CONTINUE TO
THINK THE CAP WILL BE TOO STRONG TO SUPPORT FORWARD PROPAGATING
CONVECTION AT THIS TIME.

THIS CONVECTION...IF IT GETS GOING...MAY HAVE STILL HAVE SOME
IMPACT ON OUR FORECAST. AS PREVIOUS DISCUSSION NOTED...MODELS ARE
ADVERTISING THE PRESENCE OF MID LEVEL (AROUND 500 MB) HIGH RH AIR
MOVING EAST OVER NORTH TX JUST BEFORE SUNRISE MONDAY MORNING. THE
NAM IS THE MOST AGGRESSIVE WITH THIS DEPICTION OF MID-LEVEL
MOISTURE AND FORECAST SOUNDINGS CONTINUE TO ELICIT AROUND 100 J/KG
OF VERY ELEVATED CAPE. THIS MAY BE SUFFICIENT TO ALLOW SOME MID
LEVEL UPDRAFTS TO GET GOING...ASSUMING SOME FORM OF LIFT EXISTS
NEAR THIS ELEVATED MOISTURE. IF PRECIPITATION WERE TO FORM...RAIN
WOULD NOT LIKELY REACH THE SURFACE AS PRECIPITATION WOULD HAVE TO
FALL THROUGH SEVERAL THOUSAND FEET OF DRY AIR FIRST.
REGARDLESS...THIS ACTIVITY MAY BE CAPABLE OF PRODUCING SOME
LIGHTNING STRIKES AS THE UPDRAFT BASES WOULD BE UP ABOVE 14000 FT
AND THE UPDRAFTS WOULD LIKELY CONTAIN A SUFFICIENT AMOUNT OF ICE
TO WARRANT A FEW CLOUD TO GROUND LIGHTNING STRIKES. AT THIS TIME
KEPT MENTION OF ELEVATED STORMS OUT OF THE EARLY MORNING FORECAST
AS THE NAM APPEARS TO HAVE GREATLY OVER ESTIMATED MID-LEVEL
MOISTURE FIELDS ACROSS THE HIGH TERRAIN OF NORTHERN MEXICO THIS
AFTERNOON. HOWEVER...IF ENOUGH THUNDERSTORM ACTIVITY GETS GOING
UPSTREAM OF THE CWA...THIS ACTIVITY COULD PUMP ENOUGH MID-LEVEL
MOISTURE INTO THE ATMOSPHERE FOR THE NAM'S MID-LEVEL MOISTURE
FIELDS TO COME TO FRUITION. WILL HAVE TO WAIT AND SEE HOW
MUCH...IF ANY...THUNDERSTORM ACTIVITY INITIATES TO OUR SOUTHWEST
THIS EVENING.

ON MONDAY...THE SHORTWAVE RIDGING ALOFT LOOKS TO BECOME BROKEN
DOWN BY THE PASSAGE OF THE STRONG NORTHERN STREAM TROUGH THROUGH
THE PLAINS TONIGHT. ASSUMING THIS HAPPENS...THE LOSS OF LARGE
SCALE FORCING FOR SUBSIDENCE WILL ALLOW FOR A MODIFICATION OF THE
STRONG EML IN PLACE OVER THE FORECAST AREA MOVING FORWARD. BY
MONDAY AFTERNOON...THE COLD FRONT THAT WAS NEAR AMARILLO THIS
AFTERNOON WAS STRONGLY MERIDIONALLY ORIENTED THROUGH THE PLAINS AT
THE TIME OF THIS DISCUSSION. THE TX PANHANDLE PORTION OF THE
FRONT IS EXPECTED TO REMAIN MORE OR LESS STATIONARY FOR THE NEXT
24 HOURS WHILE THE REMAINDER OF THE FRONT PIVOTS SOUTH TOWARDS THE
RED RIVER THROUGH MONDAY AFTERNOON. WHERE THE FRONT STALLS OUT
REMAINS UNCERTAIN...HOWEVER CONFIDENCE IS HIGH THAT THE FRONT WILL
STALL OUT NORTH OF INTERSTATE 20. THE DRYLINE SHOULD REMAIN WEST
OF THE FORECAST AREA FOR THE PEAK HEATING HOURS OF THE DAY.

THROUGH SUNSET...MAINTAINED A DRY FORECAST AT THIS TIME AS THE EML
CAP IS EXPECTED TO MAINTAIN ITS STRENGTH IN THE ABSENCE OF STRONG
LARGE SCALE FORCING FOR ASCENT. HOWEVER MESOSCALE FORCING COULD
LOCALLY MODIFY/LIFT THE CAP SUFFICIENTLY FOR THUNDERSTORM
INITIATION LATE MONDAY AFTERNOON OR EVENING. THE TWO OBVIOUS
SOURCES OF MESOSCALE LIFT WILL BE ALONG THE DRYLINE TO THE
WEST...AND THEN ALONG THE STALLED OUT COLD FRONT NEAR THE RED
RIVER. HIGH RESOLUTION GUIDANCE INDICATES THAT CONVECTION WILL
DEVELOP ALONG THE DRYLINE SOUTHWEST OF THE CWA IN THE 21 TO 00Z
TIMEFRAME. THE SAME GUIDANCE ALSO INDICATES THAT CONVECTION MAY
DEVELOP ALONG THE STALLED COLD FRONT NEAR PARIS AFTER 00Z. EITHER
WAY IT LOOKS AS THOUGH THESE TWO BOUNDARIES HAVE SOME CHANCE AT
BECOMING ACTIVE AFTER 00Z SO MAINTAINED 20 POPS FOR THE NORTHWEST
HALF OF THE FORECAST AREA AS A RESULT. THINK THAT THE FORCING FOR
ASCENT ALONG THE COLD FRONT ON THE EASTERN PERIPHERY OF THE EML
CAP IS THE MOST LIKELY PLACE FOR CONVECTION TO DEVELOP MONDAY
EVENING...THEREFORE KEPT 30 POPS IN PLACE FOR LOCATIONS NORTHEAST
OF THE METROPLEX AT THIS TIME. ANY STORMS THAT DEVELOP WILL HAVE A
CHANCE AT BECOMING SEVERE AS VERY HIGH CAPE VALUES IN THE PRESENCE
OF MEAGER DEEP LAYER SHEAR WILL CONTINUE TO SUPPORT PRIMARILY A
LARGE HAIL AND DAMAGING WIND THREAT.  

TUESDAY...ASSUMING THUNDERSTORMS DO NOT GROW UPSCALE AND CAUSE A
SIGNIFICANT CHANGE TO THE THERMODYNAMIC ENVIRONMENT MONDAY
NIGHT...VERY HIGH INSTABILITY...STEEP LAPSE RATES AND THE RELATIVE
POSITIONS OF THE DRYLINE AND STATIONARY FRONT SHOULD LARGELY
REMAIN UNCHANGED. SIGNIFICANT THUNDERSTORM ACTIVITY MONDAY NIGHT
WOULD LIKELY REQUIRE LARGE CHANGES TO THE FORECAST ON TUESDAY.

AS IT STANDS...OPERATIONAL GUIDANCE CONTINUES TO ADVERTISE THE
PASSAGE OF A SHORTWAVE TROUGH OVER THE SOUTHERN PLAINS DURING THE
DAY ON TUESDAY. THIS TROUGH WOULD LIKELY BE SUFFICIENT TO ALLOW
FOR THE DEVELOPMENT OF NUMEROUS THUNDERSTORMS ALONG EITHER THE
DRYLINE OR STATIONARY FRONT WHENEVER IT MOVES OVER THE REGION. THE
GFS/ECMWF AND CANADIAN MODELS ALL BRING THIS FEATURE OVER THE
PLAINS AROUND 00Z TUESDAY EVENING. ASSUMING THIS VERIFIES THIS
SHOULD RESULT IN OUR BEST PRECIPITATION CHANCES THROUGH THE
FORECAST AREA WITH STORMS GROWING UPSCALE INTO A MULTI-CELL
CLUSTER OR LINEAR MCS TUESDAY EVENING AS THEY MOVE EAST OR
SOUTHEAST THROUGH NORTH TX. THE EXACT SEVERE WEATHER THREAT IS
CONDITIONAL ON WHAT MODE THE STORMS EXIST IN. A MULTI-CELL CLUSTER
WILL CONTINUE TO SUPPORT A LARGE HAIL AND DOWNBURST WIND THREAT
WHILE A LINEAR MCS WOULD SUPPORT A MORE SIGNIFICANT DAMAGING WIND
THREAT TO NORTH TX. WILL HAVE TO WAIT AND SEE HOW THE MESOSCALE
ENVIRONMENT SETS UP ACROSS NORTH TX AFTER MONDAY EVENINGS ACTIVITY
DIMINISHES. THE SHORTWAVE TROUGH IS CURRENTLY VISIBLE JUST OFF THE
COAST OF THE BAY AREA IN CALIFORNIA ON WATER VAPOR IMAGERY.

WEDNESDAY...GUIDANCE IS COMING INTO BETTER AGREEMENT THAT TUESDAYS
CONVECTION WILL RESULT IN A NORTHWEST TO SOUTHEAST REORIENTATION
OF THE STATIONARY FRONT DURING THE DAY ON WEDNESDAY. WITH THE
ATMOSPHERE SOMEWHAT WORKED OVER FROM TUESDAYS STORMS...THINK THAT
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE MORE LIKELY
WEDNESDAY MORNING ASSOCIATED WITH REMNANTS OF TUESDAYS
THUNDERSTORM ACTIVITY. ANY BREAKS IN THE CLOUDS AND FORCING NEAR
THE FRONT SHOULD RESULT IN SOME SCATTERED THUNDERSTORMS OVER THE
NORTHEASTERN HALF OF THE CWA WEDNESDAY AFTERNOON. SEVERE WEATHER
IS MUCH LESS LIKELY AS POTENTIAL INSTABILITY IS EXPECTED TO BE
MUCH LOWER WEDNESDAY AFTERNOON WITH MEAGER MID-LEVEL LAPSE RATES
AND PARTLY CLOUDY SKIES ALL DAY.

EXTENDED...UPPER RIDGING LOOKS TO MOVE BACK OVER NORTH TX BY
THURSDAY AND HAVE MAINTAINED A DRY FORECAST FOR THE END OF THE
WEEK INTO NEXT WEEKEND AS A RESULT. TEMPERATURES ARE EXPECTED TO
REMAIN NEAR SEASONAL NORMALS AT THIS TIME.  

CAVANAUGH

&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  76  97  76  92  72 /   5  10  20  30  50 
WACO, TX              77  98  78  95  75 /   5   5  10  20  40 
PARIS, TX             72  96  74  89  70 /   5  10  30  20  50 
DENTON, TX            75  96  74  91  70 /   5  10  20  30  50 
MCKINNEY, TX          74  95  75  91  70 /   5  10  20  30  50 
DALLAS, TX            77  97  76  93  73 /   5  10  20  30  50 
TERRELL, TX           74  96  76  92  70 /   5   5  20  20  50 
CORSICANA, TX         75  97  77  94  71 /   5   5  10  20  40 
TEMPLE, TX            76  97  77  94  77 /   5   5  10  10  40 
MINERAL WELLS, TX     71  98  72  91  69 /   5  10  20  30  50 

&&

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

&&

$$

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