Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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446
FXUS64 KLIX 270948
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
348 AM CST THU NOV 27 2014

.SHORT TERM...

DEEP LAYER NORTHWEST FLOW AND STRONG NEGATIVE VORTICITY ADVECTION WILL
KEEP A DRY AND STABLE AIRMASS OVER THE FORECAST AREA THROUGH
FRIDAY. CLEAR SKIES AND COOLER THAN AVERAGE TEMPERATURES CAN BE
EXPECTED. AN UPPER LEVEL RIDGE WILL PROCEED TO CENTER ITSELF OVER
THE GULF SOUTH ON SATURDAY AND REMAIN OVER THE AREA INTO SUNDAY.
WITH STRONG SUBSIDENCE THROUGHOUT THE ATMOSPHERIC COLUMN...THE MID
AND UPPER LEVELS OF THE ATMOSPHERE WILL REMAIN DRY AND NO CHANCE
OF RAINFALL IS EXPECTED. HOWEVER...SOUTH-SOUTHWEST FLOW WILL
DEVELOP DURING THE DAY ON SATURDAY AND CONTINUE INTO SUNDAY IN THE
LOW LEVELS. THIS ONSHORE FLOW WILL USHER IN A MUCH WARMER AND MORE
HUMID AIRMASS FOR THE WEEKEND. AS THE AIRMASS MOISTENS IN THE LOW
LEVELS...THE SUBSIDENCE ALOFT WILL KEEP CONDITIONS WARM AND DRY IN
THE MID-LEVELS. THIS WILL LEAD TO THE DEVELOPMENT OF AN ELEVATED
INVERSION. EXPECT TO SEE A STRATO-CU FIELD DEVELOP SATURDAY
AFTERNOON BENEATH THIS INVERSION AND TURN INTO A THICKER STRATUS
DECK SATURDAY NIGHT. AT THIS TIME...IT APPEARS THAT BOUNDARY LAYER
FLOW WILL BE TOO STRONG FOR MUCH IN THE WAY OF ADVECTION FOG TO FORM
OVER THE WEEKEND AND HAVE LEFT OUT FOG FROM THE SATURDAY NIGHT
FORECAST FOR NOW.

.LONG TERM...

HEADING INTO NEXT WEEK...BOTH THE EURO AND THE GFS SHOW THE UPPER
LEVEL RIDGE AXIS MOVING OVER FLORIDA ON MONDAY. AT THE SAME
TIME...A WEAK SHORT-WAVE TROUGH WILL SLIDE THROUGH THE MIDWEST.
THIS WEAK UPPER LEVEL TROUGH WILL BRING A FRONTAL BOUNDARY INTO
THE LOWER MISSISSIPPI VALLEY DURING THE DAY ON MONDAY. THIS WEAK
BOUNDARY SHOULD STALL JUST NORTH OF THE FORECAST AREA AND
GRADUALLY DISSIPATE INTO MONDAY NIGHT. HOWEVER...THERE COULD BE
JUST ENOUGH MID-LEVEL MOISTURE ADVECTION AND WEAK OMEGA ALONG THE
FRONT TO SPARK OFF SOME ISOLATED SHOWERS. HAVE KEPT A SLIGHT
CHANCE OF SHOWERS IN THE FORECAST FOR SOUTHWEST MISSISSIPPI AND
THE BATON ROUGE AREA MONDAY AFTERNOON INTO MONDAY EVENING. EXPECT
TO RAIN CHANCES DIMINISH GREATLY BY TUESDAY MORNING AS THE FRONT
DISSIPATES AND ANY UPPER LEVEL SUPPORT QUICKLY PULLS TO THE EAST.
TEMPERATURES WILL CONTINUE TO WARM ON MONDAY...AND EXPECT TO SEE
READINGS AROUND 10 DEGREES ABOVE NORMAL BY THIS POINT.

THESE WARMER THE AVERAGE CONDITIONS WILL CONTINUE INTO TUESDAY AND
WEDNESDAY WITH HIGHS RISING INTO THE LOWER TO MIDDLE 70S AND
OVERNIGHT LOWS DIPPING INTO THE 50S. BOUNDARY LAYER FLOW WILL BE
SIGNIFICANTLY WEAKER EARLY NEXT WEEK...SO SOME ADVECTION FOG MAY
DEVELOP EACH NIGHT ALONG THE COAST. GIVEN THE EXTENDED TIME
FRAME...HAVE ONLY KEPT IN HIGHER THAN NORMAL SKY COVERAGE FOR THE
PERIOD AS STRATUS DEVELOPMENT IS LIKELY EACH NIGHT.

THERE ARE SOME MODEL DIFFERENCES HEADING INTO WEDNESDAY AND
THURSDAY...WITH THE EURO MODEL SHOWING A MORE PROGRESSIVE FEATURE
MOVING THROUGH THE EASTERN HALF OF THE CONUS. THE GFS HAS A MUCH
SLOWER AND WEAKER SYSTEM IMPACTING THE AREA NEXT WEEKEND. AT THIS
TIME...HAVE WENT WITH A BLEND OF THE MODEL SOLUTIONS...AND HAVE
SLIGHT CHANCE POPS IN PLACE FOR WEDNESDAY. IF THE MODELS TREND
TOWARD THE EURO OVER THE NEXT COUPLE OF DAYS...RAIN CHANCES WILL
NEED TO BE INCREASED.  OVERALL...GIVEN THE LARGE MODEL DIFFERENCES AND
TIMING ISSUES WITH SYSTEMS COMING IN FROM THE EASTERN
PACIFIC...FORECAST CONFIDENCE FOR THE MIDDLE OF NEXT WEEK IS LOWER
THAN AVERAGE.

&&

.AVIATION...

VFR CAVU CONDITIONS ARE EXPECTED AT ALL TERMINALS NEXT 24-30 HOURS. 24/RR

&&

.MARINE...

CLIPPER TYPE SYSTEM MOVING ACROSS THE OHIO VALLEY AND USHERING CONTINENTAL
COOL HIGH PRESSURE SOUTHWARD THIS MORNING. RENEWED PERIOD OF COLD AIR
ADVECTION SHOULD PRESENT SOME GUSTINESS THIS MORNING BEFORE NEUTRALIZING
THIS AFTERNOON. SMALL CRAFT ADVISORY WAS ADJUSTED SLIGHTLY TO REMOVE LAKE
BORGNE BUT REMAINS FOR OTHER AREAS TODAY. HIGH PRESSURE IS EXPECTED TO
INFLUENCE THE WIND FIELD THROUGH THE WEEKEND BEFORE MOVING EAST AND
MODERATING LATTER PART OF THE WEEKEND. ONSHORE FLOW ONSETS AHEAD OF NEXT
HIGH PRESSURE SURGE EARLY NEXT WEEK. LATEST MODEL RUNS NOW SHOW THE FRONT
MAKING IT TO THE COAST...MAYBE HIGH PRESSURE BRIDGING THE FRONT INTO THE
NORTH GULF LATER NEXT WEEK. 24/RR

&&

.DECISION SUPPORT...

DSS CODE...GREEN.
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  56  32  60  44 /   0   0   0   0
BTR  59  34  62  48 /   0   0   0   0
ASD  59  34  60  44 /   0   0   0   0
MSY  59  42  61  51 /   0   0   0   0
GPT  58  37  58  47 /   0   0   0   0
PQL  59  34  58  41 /   0   0   0   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON 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 OUT 20 NM...LAKE BORGNE...AND MISSISSIPPI
     SOUND.

     SMALL CRAFT ADVISORY UNTIL 3 PM THURSDAY FOR THE FOLLOWING
     ZONES: COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA
     FROM 20 TO 60 NM...AND COASTAL WATERS FROM STAKE ISLAND LA
     TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO
     60 NM.

MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON 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 OUT 20 NM...LAKE BORGNE...AND MISSISSIPPI
     SOUND.

     SMALL CRAFT ADVISORY UNTIL 3 PM THURSDAY FOR THE FOLLOWING
     ZONES: COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA
     FROM 20 TO 60 NM...AND COASTAL WATERS FROM STAKE ISLAND LA
     TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO
     60 NM.

&&

$$

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