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

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000
FXUS64 KLIX 201009
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
509 AM CDT SAT SEP 20 2014

.SYNOPSIS...A WEAK COLD FRONT HAS PUSHED SOUTH INTO THE NORTH GULF
COASTAL WATERS. IN THE UPPER LEVELS...WATER VAPOR IMAGERY LOOPS
SHOW AN AMPLIFIED TROUGH FROM THE SOUTHEAST STATES INTO THE
CENTRAL GULF OF MEXICO DRIVING DRY AIR SOUTHEAST. CONVERGENCE DUE
TO STRONGER EASTERLY WINDS OFFSHORE IS RESULTING IN ISOLATED
SHOWERS NEAR AND SOUTH OF THE FRONTAL BOUNDARY.

.SHORT TERM /TODAY THROUGH SUNDAY NIGHT/...

A STATIONARY FRONTAL BOUNDARY IS EXPECTED TO MEANDER NEAR THE
NORTH GULF COAST AND ADJACENT COASTAL WATERS THROUGH THE WEEKEND.
THE AMPLIFIED UPPER LEVEL PATTERN OVER THE GULF STATES WILL
MAINTAIN FAIRLY DRY AIR OVER THE CENTRAL GULF COAST REGION. THIS
WILL MAINTAIN A MAINLY DRY PATTERN THROUGH THE WEEKEND WITH
LESS HUMID AIR OVER MOST AREAS...AND ANY ISOLATED SHOWERS AND
THUNDERSTORMS SHOULD BE LIMITED TO THE IMMEDIATE COASTAL AREAS OF
SOUTHEAST LOUISIANA AND THE COASTAL WATERS TO THE SOUTH AND
SOUTHEAST. SKIES ARE EXPECTED TO BE CLEAR TO PARTLY CLOUDY...AND
TEMPERATURES ARE EXPECTED TO BE NEAR TO SLIGHTLY ABOVE NORMAL FOR
HIGHS WITH LOWS NEAR NORMAL.

.LONG TERM /MONDAY THROUGH FRIDAY NIGHT/...

A SERIES OF SHORTWAVE TROUGHS MOVING SOUTHEAST OUT OF CANADA INTO
THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES REGION WILL AMPLIFY A
PROGRESSIVE SHORTWAVE TROUGH AXIS DOWN INTO THE TENNESSEE VALLEY
AND MID ATLANTIC REGION SUNDAY NIGHT INTO MONDAY. THIS WILL DRIVE
A REINFORCING COLD FRONT SOUTH INTO THE GULF COAST REGION. USING A
CONSENSUS OF THE MODELS...THERE APPEARS TO BE A SUFFICIENT
COMBINATION OF MOISTURE...LIFT AND INSTABILITY FOR AT LEAST
ISOLATED TO POSSIBLY SCATTERED SHOWERS AND THUNDERSTORMS TO
DEVELOP ALONG THE FRONTAL BOUNDARY MONDAY AFTERNOON...ESPECIALLY
OVER CENTRAL AND SOUTHERN PORTIONS OF THE FORECAST AREA. RAINFALL
AMOUNTS SHOULD BE MOSTLY LIGHT TO MODERATE.

ANOTHER PUSH OF DRIER AIR IS EXPECTED TO PUSH OFFSHORE AND BRING
MORE OF A TASTE OF AUTUMN TO THE REGION. LOWS MONDAY NIGHT AND
TUESDAY NIGHT ARE EXPECTED TO DROP TO THE LOWER TO MID 60S OVER
AREAS ALONG AND NORTH OF THE I-10/LAKE PONTCHARTRAIN CORRIDOR WITH
UPPER 60S TO LOWER 70S SOUTH OF I-10 IN LOUISIANA. EVEN THE HIGHS
SHOULD BE A BIT BELOW NORMAL WITH MID 80S EXPECTED STARTING
TUESDAY AND CONTINUING THROUGH MOST OF NEXT WEEK. THE LOWS SHOULD
START TO RECOVER WEDNESDAY NIGHT THROUGH THE WEEK AS THE FRONT
WASHES OUT OR REPOSITIONS CLOSER TO THE COAST. PERSISTENT
EASTERLIES NEAR THE COAST WITH INVERTED TROUGH FEATURES MOVING
FROM EAST TO WEST...OR SOUTHEAST TO NORTHWEST WILL RESULT IN
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS IN COASTAL AREAS
THURSDAY INTO FRIDAY WITH LOWER CHANCES OVER INLAND AREAS WHERE
THE DRY AIR WILL BE HARDER TO DISLODGE. 22/TD

&&

.MARINE...

A TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE COASTAL WATERS
THROUGH EARLY TONIGHT AS A BROAD AREA OF LOW PRESSURE OVER THE
CENTRAL GOMEX INTERACTS WITH A STRONG RIDGE OF HIGH PRESSURE OVER
THE SOUTHEASTERN CONUS.  EAST WINDS OF 20 TO 25 KNOTS WILL PERSIST
OVER THE GULF COASTAL WATERS WITH WINDS OF 15 TO 20 KNOTS EXPECTED
IN THE SOUNDS.  THE PRESSURE GRADIENT WILL WEAKEN LATE TONIGHT AND
TOMORROW AS THE LOW DEGRADES IN THE GULF AND THE HIGH OVER THE
SOUTHEAST SHIFTS TO THE EAST. THIS WILL ALLOW THE EASTERLY FLOW TO
DECREASE TO AROUND 10 TO 15 KNOTS AND SEAS TO FALL BACK TO
AROUND 2 TO 4 FEET BY SUNDAY EVENING. HEADING INTO MONDAY...A WEAK
FRONTAL BOUNDARY WILL SLIP INTO THE COASTAL WATERS AND PUSH INTO
THE NORTHERN GOMEX BY TUESDAY MORNING. WITH STRENGTHENING HIGH
PRESSURE BUILDING IN FROM THE NORTH...THE GRADIENT FLOW WILL ONCE
AGAIN INCREASE FOR WEDNESDAY AND THURSDAY. EXPECT TO SEE EASTERLY
FLOW INCREASE BACK TO NEAR SMALL CRAFT ADVISORY RANGE DURING THIS
PERIOD. 32

&&

.AVIATION...

A MUCH DRIER AND MORE STABLE AIRMASS IS IN PLACE ACROSS THE FORECAST
AREA.  AS A RESULT...VFR CONDITIONS WILL GENERALLY BE THE RULE AT
ALL OF THE TERMINALS THROUGH THE FORECAST PERIOD.  HOWEVER...A WEAK
LOW LEVEL INVERSION IS EXPECTED TO DEVELOP OVER INLAND TERMINALS
EARLY THIS MORNING AND ONCE AGAIN LATE TONIGHT.  HAVE INCLUDED A
TEMPO GROUP AT MCB...HDC...ASD...BTR...AND HUM WITH SOME LIGHT FOG
WORDING TO INCLUDE MVFR VISIBILITY RESTRICTIONS.  A VERY SIMILAR
PATTERN IS EXPECTED FOR LATE TONIGHT...GENERALLY AFTER 09Z.  32

&&

.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT AND SUPPORTING USCG SSW OF PASCAGOULA.

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.
&&

.DECISION SUPPORT...

DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT AND SUPPORTING USCG SSW OF PASCAGOULA.

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  89  66  90  66 /   0   0   0  10
BTR  90  69  91  68 /   0  10   0   0
ASD  89  69  90  69 /  10  10  10   0
MSY  89  75  90  74 /  10  10  10   0
GPT  89  71  89  70 /  10  10  10  10
PQL  88  67  89  66 /  10  10  10  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM SATURDAY FOR THE FOLLOWING
     ZONES: 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 7 PM SATURDAY FOR THE FOLLOWING
     ZONES: 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.

&&

$$






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