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

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417
FXUS64 KLIX 221351
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
751 AM CST THU JAN 22 2015

...SOUNDING DISCUSSION...

THE SOUNDING THIS MORNING HAS EASTERLY WINDS NEAR THE SFC UP TO 35
KTS AT 1000 FT. NEAR 850 MB THE WINDS SWITCH TO THE WEST WITH A 118
KT JET MAX AT 195 MB. LOW LEVELS ARE STILL DRY... THOUGH THE
SOUNDING BECOMES SATURATED AT 600 MB.

AK

&&

.PREV DISCUSSION... /ISSUED 351 AM CST THU JAN 22 2015/

DISCUSSION...
ONLY REAL WEATHER ISSUES WILL BE IN THE FIRST 48 HOURS AS A
SURFACE LOW MOVES THROUGH THE NORTHERN GULF OF MEXICO. UPPER
TROUGH CURRENTLY DIGGING INTO THE SOUTHWEST CONUS WILL FORCE
DEVELOPMENT OF SURFACE LOW OVER THE WESTERN GULF BY THIS EVENING.
THIS LOW WILL THEN MOVE EAST/NORTHEASTWARD INTO THE FLORIDA
PANHANDLE AS THE UPPER TROUGH SWINGS THROUGH THE LOWER
MISSISSIPPI VALLEY. AS THE LOW MOVES THROUGH THE GULF...RAIN WILL
SPREAD ACROSS THE GULF SOUTH TODAY AND TONIGHT. ALREADY SEEING
RADAR RETURNS ACROSS NORTHWESTERN PORTIONS OF THE REGION THIS
MORNING...BUT MOST OF THIS PRECIPITATION IS LIKELY EVAPORATING
BEFORE REACHING THE GROUND AS THERE IS STILL SIGNIFICANT DRY AIR
BELOW ABOUT 600MB/14KFT.

WILL TAKE A WHILE FOR MOISTURE TO WORK ITS WAY DOWN INTO THE LOWER
PART OF THE ATMOSPHERE...SO AM CARRYING SLIGHT CHANCE TO LOW END
CHANCE POPS FOR THE FIRST PART OF THIS MORNING...GRADUALLY
INCREASING FROM WEST TO EAST THROUGHOUT THE DAY AND RISING TO
LIKELY TO DEFINITE POPS BY LATE THIS AFTERNOON. ANY PRECIP SHOULD
BE LIGHT DURING THE MORNING HOURS...WITH MORE MODERATE RAINFALL
POSSIBLE THIS AFTERNOON. HIGHEST COVERAGE WILL OCCUR OVERNIGHT...
WITH 100 PERCENT POPS FOR THE ENTIRE AREA. THE SURFACE LOW IS
EXPECTED TO REMAIN OVER THE GULF OF MEXICO AS IT PASSES BY THE
LOCAL AREA...WHICH SHOULD KEEP THREAT OF THUNDERSTORMS LIMITED TO
COASTAL WATERS AND POSSIBLY IMMEDIATE COASTAL AREAS OF SOUTHEAST
LOUISIANA. ONCE THE LOW MOVES EAST OF THE LOCAL AREA...RAIN
WILL BECOME LIGHTER AND POPS WILL SLOWLY TAPER DOWN. RAIN WILL
CONTINUE TO BE POSSIBLE THROUGH FRIDAY NIGHT WHEN THE UPPER TROUGH
AXIS FINALLY MOVES EAST OF THE LOCAL AREA AND DRIER HIGH PRESSURE
BUILDS IN. STORM TOTAL RAINFALL IS FORECAST IN THE 1 TO 3 INCH
RANGE...SPREAD OUT OVER ABOUT 48 HOURS SO NO SIGNIFICANT ISSUES
ARE EXPECTED.

ONCE THE RAIN CLEARS OUT...NO OTHER PRECIPITATION IS FORECAST
THROUGH THE 7 DAY PERIOD. DRY HIGH PRESSURE WILL BUILD INTO THE
AREA AND BE REINFORCED EARLY NEXT WEEK AS ANOTHER UPPER TROUGH
DIGS INTO THE SOUTHEASTERN CONUS. TEMPERATURES WILL BE NEAR
TO BELOW NORMAL THROUGH THE PERIOD.

AVIATION...
EXPECT VFR CONDITIONS THROUGH THE MORNING HOURS TODAY...THEN TOP
DOWN SATURATION AND A STRONG OVERRUNNING SETUP WILL LEAD TO LOWER
CIGS OF 020-030 AND LIGHT RAIN DEVELOPING 19-21Z THIS AFTERNOON. A
CONTINUED LOWERING OF CONDITIONS TO LOW END MVFR AND IFR IS LIKELY
BY 22-24Z THIS AFTERNOON/EVENING...AND THESE LOW CONDITIONS WILL
PERSIST THROUGH TONIGHT AND FRIDAY. RAIN WILL BE FAIRLY STEADY AND
MODERATE TO HEAVY AT TIMES TONIGHT WITH A FEW BRIEF TSRA POSSIBLE
MAINLY IN COASTAL AREAS OF SOUTHEAST LOUISIANA.

MARINE...
AN AREA OF LOW PRESSURE AROUND 1012 MB IS EXPECTED TO DEVELOP IN
THE  NORTHWEST GULF OFF THE TEXAS COAST THIS AFTERNOON. THE LOW IS
THEN EXPECTED TO KEEP THE SAME PRESSURE AND ELONGATE NORTHEAST TO
SOUTHWEST AS IT MOVES EAST-NORTHEAST TONIGHT AND FRIDAY MORNING
ACROSS THE SOUTHEAST LOUISIANA OFFSHORE COASTAL WATERS SOUTH THROUGH
EAST OF SOUTHWEST PASS. WINDS ARE EXPECTED TO RISE TO NEAR OR ABOVE
SMALL CRAFT ADVISORY /SCA/ CRITERIA THIS MORNING ACROSS ALL WATERS
EXCEPT LAKES PONTCHARTRAIN/MAUREPAS AND THE OFFSHORE CENTRAL COASTAL
WATERS ZONES. ALL WATERS WILL THEN LIKELY EXPERIENCE SCA CONDITIONS
TONIGHT INTO FRIDAY MORNING...AND AGAIN LATE FRIDAY AFTERNOON
THROUGH EARLY SATURDAY MORNING. HAVE ADJUSTED THE STARTING TIME OF
SCA BASED ON THIS FORECAST. AREAS OF LIGHT RAIN WILL DEVELOP THIS
MORNING TO AROUND MIDDAY...THEN MORE WIDESPREAD RAIN AND SHOWERS
WILL DEVELOP THIS AFTERNOON AND TONIGHT BEFORE DIMINISHING FROM THE
COAST OFFSHORE ON FRIDAY AFTERNOON AND EVENING. ISOLATED
THUNDERSTORMS ARE ALSO POSSIBLE IN THE COASTAL WATERS TONIGHT INTO
EARLY FRIDAY MORNING.

WINDS SHOULD EASE BACK TO 10 TO 15 KNOTS BY LATE SATURDAY AFTERNOON
THROUGH SUNDAY MORNING...THEN ANOTHER SURGE OF COOLER AIR WILL
LIKELY BRING WINDS BACK UP TO 15 TO 20 KNOTS LATE SUNDAY INTO MONDAY
MORNING.

DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
             SMALL CRAFT ADVISORY

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  55  42  48  34 / 100 100  50  30
BTR  57  42  49  35 / 100 100  40  30
ASD  60  46  52  37 /  80 100  50  30
MSY  61  46  51  38 /  80 100  50  20
GPT  60  47  53  38 /  80 100  50  30
PQL  60  49  54  38 /  70 100  60  30

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 AM SATURDAY 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 THE SOUTHWEST PASS OF
     THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
     BORGNE...AND MISSISSIPPI SOUND.

     SMALL CRAFT ADVISORY FROM 6 PM THURSDAY TO NOON SATURDAY FOR THE
     FOLLOWING ZONES: COASTAL WATERS FROM STAKE ISLAND LA TO THE
     SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60
     NM...AND COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM.

     SMALL CRAFT ADVISORY FROM 5 PM THURSDAY TO 6 AM SATURDAY FOR THE
     FOLLOWING ZONES: AND LAKE PONTCHARTRAIN AND LAKE MAUREPAS.

MS...NONE.
GM...SMALL CRAFT ADVISORY FROM 5 PM THURSDAY TO 6 AM SATURDAY FOR THE
     FOLLOWING ZONES: AND LAKE PONTCHARTRAIN AND LAKE MAUREPAS.

     SMALL CRAFT ADVISORY UNTIL 9 AM SATURDAY 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 THE SOUTHWEST PASS OF
     THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
     BORGNE...AND MISSISSIPPI SOUND.

     SMALL CRAFT ADVISORY FROM 6 PM THURSDAY TO NOON SATURDAY FOR THE
     FOLLOWING ZONES: COASTAL WATERS FROM STAKE ISLAND LA TO THE
     SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60
     NM...AND COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM.

&&

$$







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