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000
FXUS64 KLIX 121314
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
714 AM CST THU DEC 12 2013


.SOUNDING DISCUSSION...
NO PROBLEMS WITH LAUNCH THIS MORNING. CLOUD COVER CLEARED ABOUT AN
HOUR PRIOR TO LAUNCH AND SOUNDING REFLECTS THE DRYNESS WITH A
PRECIPITABLE WATER OF 0NLY 0.47 INCHES. VERY STABLE WITH LI OF
17.7. SURFACE BASED FRONTAL INVERSION TO 8KFT THEN PSEUDO LAPSE
RATE THROUGH TROPOPAUSE AT 195 MB. WINDS WERE NE 10-25 KT SURFACE
TO 2800 FT...THEN NW-W 15 TO 115 KT ABOVE. PEAK WIND 260/115KT AT
44.6KFT. FLIGHT TERMINATED 90 MILES EAST OVER COASTAL EAST ALABAMA
NEAR GRAND BAY NEAR THE INTERSECTION OF HENDERSON CAMP ROAD AND MARINE
LABORATORY ROAD AT AN ALTITUDE OF 33178 M OR 20.6 MILES UP AT 7.5
MB. 24/RR

&&

.PREV DISCUSSION... /ISSUED 333 AM CST THU DEC 12 2013/

SHORT TERM...
RE-ENFORCING SURGE OF COLD AIR CONTINUED TO BUILD SOUTHWARD
THIS MORNING WITH MUCH OF WESTERN LOUISIANA AND MISSISSIPPI EXCEPT
THE COAST IN THE 30S. A STUBBORN MID-LAYER CLOUD DECK BEGINNING TO
ERODE FROM NORTH TO SOUTH AS FRONT ADVANCES. SKIES SHOULD BECOME
MOSTLY CLEAR DURING THE MORNING BUT COLD AIR ADVECTION KEEPING A
SMALL DIURNAL RANGE ON TEMPERATURES TODAY. A COLD NIGHT IS IN
STORE UNDER STRONG RADIATIONAL COOLING...FOLLOWED BY GRADUAL
WARMING FRIDAY AS MODIFYING ARCTIC HIGH MOVES QUICKLY EASTWARD.
FLOW BECOMES ONSHORE ORIENTED THROUGHOUT THE DAY FRIDAY AND SOME
ADVECTIVE FOG MAY RESULT AS DEWPOINTS RISE THROGH THE 50S INTO THE
LOWER 60S OVERNIGHT FRIDAY NIGHT AND EARLY SATURDAY MORNING.
INTRODUCED FOG IN WEATHER GRIDS FOR AREAS DOWNWIND OF MARINE LAYER
ADVECTION. TEMPERATURES WILL LIKELY WARM OVERNIGHT FRIDAY NIGHT.
MODEL SOUNDINGS STILL SHOW LIMITED CAPES FOR THUNDER DEVELOPMENT
BUT MAY ATTAIN SOME SURFACE BASED LIFT CHARACTERISTICS OVER THE
COASTAL WATERS AND NEAR SHORE AREAS BY SATURDAY MORNING. MAIN
CONVECTIVE MODE SHOULD BE SHOWERS BUT WILL LEAVE ISOLATED THUNDER
WITH FRONTAL FORCING IN WARM SECTOR. 24/RR

LONG TERM...
LOW PRESSURE AREA MOVES NORTHEAST OF AREA SATURDAY AFTERNOON WITH
SOME LINGERING STRATIFORM RAIN AND ELEVATED SHOWERS POSSIBLE PRIOR
TO UPPER TROUGH PASSAGE SUNDAY MORNING. MODELS ARE IN PRETTY GOOD
AGREEMENT WITH TROUGH AXIS PASSAGE THOUGH GFS MAY BE SLIGHTLY
FASTER THAN ECMWF AND WENT WITH THE MORE OPTIMISTIC GFS TIMING.
COLD NORTHWEST FLOW BECOMES ESTABLISHED AND PERSISTS THROUGH AT
LEAST MID-WEEK BEFORE ANOTHER LOW PRESSURE SYSTEM AND COLD FRONT
DEVELOPS IN THE PLAINS STATES LATTER PART OF NEXT WEEK. ONSHORE
FLOW AND BAROCLINIC RETURN SHOULD INDUCE A SHOWERY REGIME LATE
NEXT THURSDAY INTO FRIDAY. 24/RR

AVIATION...
A MID-LEVEL CLOUD DECK CONTINUES TO RAPIDLY CLEAR...WITH SKC
CONDITIONS NOW OCCURING AT KMCB...KBTR...AND KHDC.  THE CLEARING
LINE WILL CONTINUE TO PUSH TO THE SOUTH...BRINGING SKC CONDITIONS TO
THE REMAINING TERMINALS BY 15Z.  VFR CONDITIONS WILL THEN DOMINATE
AT ALL OF THE TERMINALS THROUGH TOMORROW MORNING.  STRONG COLD AIR
ADVECTION ACROSS LAKE PONTCHARTRAIN WILL ALLOW FOR A PERIOD OF
STRONG NORTHERLY WINDS IN EXCESS OF 12 KNOTS THROUGH AROUND 00Z. 32

MARINE...
INCREASED GRADIENT FLOW ASSOCIATED WITH A STRONG 1035MB SURFACE HIGH
BUILDING INTO THE REGION WILL ALLOW FOR A PERIOD OF SMALL CRAFT
ADVISORY CONDITIONS OVER THE GULF COASTAL WATERS AND THE CHANDELEUR
AND BRETON SOUNDS THROUGH THIS EVENING.  EXERCISE CAUTION WILL
IMPACT THE TIDAL LAKES AND MISSISSIPPI SOUND.  THE HIGH WILL SETTLE
OVER THE REGION TONIGHT...AND THE OVERALL PRESSURE GRADIENT ACROSS
THE REGION WILL RELAX.   EXERCISE CAUTION CONDITIONS WILL LINGER
OVER THE GULF COASTAL WATERS TONIGHT...AND WILL FURTHER DROP TO
BELOW 15 KNOTS BY TOMORROW MORNING.  THE HIGH WILL QUICKLY PULL TO
THE EAST FRIDAY NIGHT...WITH INCREASED SOUTHEAST FLOW DEVELOPING IN
ADVANCE OF A DEEPENING SURFACE LOW.  EXERCISE CAUTION CONDITIONS
WILL DEVELOP BY FRIDAY EVENING AND PERSIST THROUGH THE NIGHT. THE
LOW WILL SWEEP THROUGH ON SATURDAY...ALLOWING WINDS TO SHIFT TO A
MORE WESTERLY DIRECTION BY SATURDAY AFTERNOON.  WINDS WILL INCREASE
BY SATURDAY NIGHT AND SHIFT TO THE NORTHWEST...AS A COLDER AIRMASS
ADVECTS INTO THE REGION IN THE WAKE OF A PASSING UPPER LEVEL TROUGH
AXIS.  WINDS WILL RISE BACK TO NEAR ADVISORY RANGE SATURDAY NIGHT
AND REMAIN NEAR 20 KNOTS THROUGH THE DAY ON SUNDAY.  WINDS WILL
GRADUALLY EASE SUNDAY NIGHT INTO MONDAY...AS THE SURFACE HIGH
SETTLES OVER THE GULF SOUTH.  32

DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.

DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN  = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE   = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
         VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
         WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
         TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED    = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
         AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
         SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  52  29  60  53 /   0   0  10 100
BTR  53  32  63  57 /   0  10  10  90
ASD  55  32  64  58 /   0   0  10  70
MSY  55  40  66  60 /   0  10  10  60
GPT  56  33  63  61 /   0   0  10  50
PQL  56  30  64  62 /   0   0  10  40

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM THURSDAY FOR THE FOLLOWING
     ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS
     FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI
     RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO
     STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM
     PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS
     FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60
     NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA
     RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO
     THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60
     NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...AND
     COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
     RIVER TO PORT FOURCHON OUT 20 NM.

MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM THURSDAY FOR THE FOLLOWING
     ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL WATERS
     FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI
     RIVER OUT 20 NM...COASTAL WATERS FROM PASCAGOULA MS TO
     STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL WATERS FROM
     PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM...COASTAL WATERS
     FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60
     NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA
     RIVER OUT 20 NM...COASTAL WATERS FROM STAKE ISLAND LA TO
     THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60
     NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM...AND
     COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI
     RIVER TO PORT FOURCHON OUT 20 NM.

&&

$$