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

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004
FXUS64 KLIX 240835
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
335 AM CDT WED SEP 24 2014

.SYNOPSIS...

HIGH PRESSURE REMAINS CENTERED OVER THE NORTHEASTERN STATES.
STATIONARY FRONT OVER THE GULF AT ABOUT 27N LATITUDE. SOME CIRRUS
ACROSS WESTERN PORTIONS OF THE AREA AND A FEW CLOUDS BETWEEN FL030
AND FL050 OVER THE GULF AND IMMEDIATE COAST...BUT THE CLOSEST
PRECIPITATION IS OVER THE CENTRAL GULF. TEMPERATURES AWAY FROM
MARINE INFLUENCES ARE GENERALLY IN THE 60S.

&&

.SHORT TERM...

DRY AIR REMAINS IN PLACE THROUGH FRIDAY. ANY ISOLATED
PRECIPITATION SHOULD REMAIN OVER THE COASTAL WATERS AND ADJACENT
SHORELINES. MAY HAVE A LITTLE MORE HIGH CLOUDINESS TO PREVENT
TEMPERATURES FROM MAXING OUT...ESPECIALLY OVER WESTERN PORTIONS OF
THE AREA. NAM SOLUTION BY FRIDAY APPEARS TO BE A LITTLE
OVERAGGRESSIVE WITH AN INVERTED TROF MOVING WESTWARD ACROSS THE
AREA...A FEATURE THAT IS NOT EMPHASIZED IN THE GFS/ECMWF
SOLUTIONS. WILL TREND TOWARD THE WARMER SOLUTIONS ON HIGH
TEMPERATURES. LOW TEMPERATURE FORECASTS SEEM TO BE PRETTY CLOSE
AND WILL GO WITH A BLENDED SOLUTION. 35

&&

.LONG TERM...

GFS AND ECMWF ARE FAIRLY CLOSE WITH THEIR PATTERN EVOLUTION
THROUGH MIDDAY SUNDAY...AT WHICH POINT THE ECMWF TENDS TO BE MORE
SUPPORTIVE OF A BIT STRONGER UPPER LOW OVER THE ARKLATEX. THE GFS
GIVES A LITTLE MORE SUPPORT TO A STRONGER NORTHERN STREAM IMPULSE.
THIS MEANS THE ECMWF IS A BIT STRONGER ON AN INVERTED SURFACE TROF
THAT MOVES ACROSS THE AREA SUNDAY AND MONDAY. BOTH SOLUTIONS BRING
PRECIPITATION TO THE AREA FOR SATURDAY THROUGH SUNDAY NIGHT. THE
PREVIOUS FORECAST POP TRENDS FIT WELL WITH OUR NEIGHBORS AND HAVE
OPTED TO MAKE LITTLE CHANGE. THE ECMWF SOLUTION WOULD INDICATE WE
MAY NEED TO BUMP POPS UP SLIGHTLY...MAYBE ANOTHER 10 PERCENT...FOR
SATURDAY AND SATURDAY NIGHT IN LATER FORECASTS. HAVE NOT HOPPED
TOTALLY ON BOARD OF THE ECMWF SOLUTION YET...WHICH WOULD REQUIRE
DRYING OUT THE FORECAST ON MONDAY AND TUESDAY. KEEPING MINIMAL
POPS IN PLACE THERE FOR NOW...CLOSER TO GFS SOLUTION. TEMPERATURES
NEAR TO A LITTLE ABOVE NORMAL FOR THE EXTENDED PERIOD...BUT MAY
NEED TO TEMPER HIGHS SOMEWHAT IF WETTER SOLUTIONS PREVAIL. 35

&&

.AVIATION...

VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST THURSDAY. SOME
SCATTERED TO BROKEN CLOUD DECKS FROM 030-050 WERE OBSERVED IN
SATELLITE IMAGERY AND SURFACE OBSERVATIONS NEAR THE EXTREME
SOUTHEAST LOUISIANA COAST AND OFFSHORE IN THE GULF. THESE CLOUDS
WILL MOVE ONSHORE ACROSS SOME OF THE SOUTHEAST LA AIRPORTS THIS
MORNING AND EARLY AFTERNOON BEFORE DRY AIR MIXES OUT THE CLOUDS
LATER IN THE AFTERNOON. ANY CIGS SHOULD BE BRIEF SO HAVE ONLY
CARRIED SCATTERED COVERAGE IN THE TAFS. 22/TD

&&

.MARINE...

THE SURFACE FEATURES AFFECTING THE MARINE WINDS WILL NOT CHANGE MUCH
THROUGH ABOUT SATURDAY WITH THE DOMINANT FEATURES BEING A LARGE HIGH
PRESSURE RIDGE COVERING THE EASTERN U.S. AND SOUTHEAST CANADA...AND
A STALLED FRONTAL BOUNDARY OVER THE CENTRAL GULF OF MEXICO. THE MAIN
FORECAST ISSUE WILL BE ANY WEAK WAVES OR INVERTED TROUGH FEATURES
THAT MAY DEVELOP NEAR TO NORTH OF THE FRONTAL ZONE OVER THE NORTH
CENTRAL GULF THAT MAY TIGHTEN THE PRESSURE GRADIENT AND INCREASE THE
EASTERLY WIND SPEEDS. ONE OTHER THING THAT COULD AT LEAST LOCALLY
PRODUCE HIGHER WINDS IS FLARE UPS OF DEEPER CONVECTION. RIGHT
NOW...AM NOT KEYING IN ON ANY SUBSTANTIAL WAVE FEATURES THAT WILL
HAVE A BIG IMPACT ON WINDS...BUT THAT WILL HAVE TO BE WATCHED OVER
THE NEXT FEW DAYS.

HAVE GENERALLY USED A BLEND OF THE MODELS AND PREVIOUS FORECASTS.
WILL BE KEEPING THE SMALL CRAFT ADVISORY THROUGH THURSDAY MORNING
FOR THE EASTERNMOST TWO COASTAL WATERS ZONES WHERE WINDS SHOULD
REMAIN NEAR 20 KNOTS AND/OR SEAS NEAR 7 FEET. ELSEWHERE...THE
REMAINING COASTAL WATERS AND SOUNDS SHOULD STAY MOSTLY IN THE 15 TO
20 KNOTS RANGE WITH THE TIDAL LAKES MOSTLY 15 KNOTS OR LESS THROUGH
THURSDAY MORNING. FROM THURSDAY AFTERNOON THROUGH ABOUT MIDDAY ON
SATURDAY...EASTERLY WINDS SHOULD AVERAGE AROUND 15 KNOTS OVER
OFFSHORE WATERS AND 10 TO 15 KNOTS OVER NEAR SHORE WATERS...SOUNDS
AND TIDAL LAKES. THE PRESSURE GRADIENT SHOULD WEAKEN SUBSTANTIALLY
TO BRING WINDS DOWN TO AROUND 10 KNOTS OR LESS BY SUNDAY AFTERNOON
INTO EARLY NEXT WEEK AS HIGH PRESSURE WEAKENS AND A WEAK TROUGH
MOVES OVER THE CENTRAL GULF COAST REGION. THE MOST LIKELY TIME FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WITH LOCALLY
STRONGER WIND GUSTS WILL BE FROM FRIDAY NIGHT THROUGH MONDAY
MORNING. 22/TD

&&

.DECISION SUPPORT...

DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SMALL CRAFT ADVISORY...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  84  61  85  63 /  10   0  10  10
BTR  86  64  87  64 /  10   0  10  10
ASD  85  63  86  66 /  10   0  10  10
MSY  85  70  85  71 /  10   0  10  10
GPT  85  66  85  67 /  10   0  10  10
PQL  84  62  85  65 /  10   0  10  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM THURSDAY FOR THE FOLLOWING
     ZONES: COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA
     FROM 20 TO 60 NM...AND COASTAL WATERS FROM PASCAGOULA MS TO
     STAKE ISLAND LA OUT 20 NM.

MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM THURSDAY FOR THE FOLLOWING
     ZONES: COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA
     FROM 20 TO 60 NM...AND COASTAL WATERS FROM PASCAGOULA MS TO
     STAKE ISLAND LA OUT 20 NM.

&&

$$







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