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

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556
FXUS64 KLIX 131702
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1202 PM CDT SAT SEP 13 2014

.AVIATION...
...18Z TAF ISSUANCE...
POST-FRONTAL LOW CLOUDS SHOULD SLOWLY ERODE WITH DAYTIME HEATING
THIS AFTERNOON BUT RUN MVFR SCT-BKN BASES THIS AFTERNOON.
CONVECTION WILL BE SOMEWHAT LIMITED IN COVERAGE DUE TO CLOUD COVER
BUT WHERE BREAKS DO OCCUR...THIS WILL ONSET DIFFERENTIAL HEATING
FOR CONVECTIVE GENERATION...PARTICULARLY ALONG LAKE BREEZE
BOUNDARIES THAT MAY INTERACT WITH MESO-SCALE OUTFLOW BOUNDARIES
MAINLY AT THE SOUTH SHORE TAF LOCATIONS THROUGH 00Z.

&&

.PREV DISCUSSION... /ISSUED 912 AM CDT SAT SEP 13 2014/

UPDATE...
..SOUNDING DISCUSSION...

NO PROBLEMS WITH THE FLIGHT THIS MORNING. THE SOUNDING SHOWS A
GOOD DEAL OF MOISTURE IN THE LOWER LEVELS OF THE ATMOSPHERE...WITH
PW VALUES NEAR 2.1 INCHES. AS THE BALLOON WAS LAUNCHED...WINDS
WERE LIGHT AND OUT OF THE EAST JUST OFF OF THE SURFACE. SINCE
THEN...WINDS HAVE PICKED UP AND SHIFTED TO THE NORTH AS THE FRONT
MOVED INTO THE AREA. THE FRONT WILL SURELY DICTATE WHERE
CONVECTION DEVELOPS TODAY WITH THE BEST CHANCES BEING SOUTH OF THE
LAKE AND ESPECIALLY WHERE THE FRONT MIGHT STALL. THE BIGGEST
THREAT FROM ANY STORMS TODAY WILL BE HEAVY RAINFALL WITH STORM
MOTION FROM THE SOUNDING AT ONLY 2 KNOTS.

98/SO

PREV DISCUSSION... /ISSUED 452 AM CDT SAT SEP 13 2014/

SHORT TERM...OVERALL THINGS HAVE BEEN FAIRLY QUIET WITH NO
CONVECTION OVER THE AREA SINCE LATE THIS EVNG. AS FOR THE COLD FRONT
IT APPEARS THAT IT HAS SUNK INTO THE CWA BUT HASNT REALLY MOVED MUCH
AND AS OF 8Z IS STILL LOCATED FROM NEAR LCH TO BTR TO BXA AND NORTH
OF MOB.

TODAY MAIN FCST ISSUE IS CONVECTION AND COVERAGE. GLOBAL MDLS
CONTINUE TO INDICATE FRONT SINKING SOUTH JUST OFF THE COAST BUT
GIVEN THE SLOWER PROGRESSION OF THE FRONT COMPARED TO THE MDLS
THINKING IS THIS FRONT WILL LIKELY STALL OVER THE AREA PROVIDING
WEAK LL CONVERGENCE. COMBINE THAT WITH SEA BREEZE AND LAKE BREEZE
INTERACTIONS AND THERE SHOULD BE DECENT COVERAGE OF CONVECTION OVER
THE SERN HALF OF THE CWA AND HAVE GONE ABV GUI FOR THOSE LOCATIONS.
AS HAS BEEN MENTIONED OVER THE LAST FEW DAYS WITH THIS FRONT SITTING
OVER THE AREA THERE IS THE POTENTIAL FOR HEAVY RAIN IF
BANDING/TRAINING FOR STORMS DEVELOPS. IF ENOUGH CONVECTION DEVELOPS
THEN THERE IS THE CHANCE THAT OUTFLOW/COLD POOLING COULD NUDGE THE
FRONT SOUTH INTO THE GULF AND THIS COULD LEAD TO LITTLE IF ANY RAIN
ACROSS SWRN MS AND EVEN TWRDS THE BTR METRO.

SUN LOOK FOR MORE RAIN ALONG THE COAST. OUR FRONT SHOULD BE RIGHT ON
THE COAST AND ACT AS A FOCUS AS WE HEAT UP. HEAVY RAIN IS A CONCERN
AGAIN AND WITH ABUNDANT MOISTURE IN PLACE WE COULD SEE AN INCH OR
TWO OVER LOCATIONS NEAR THE COAST. OVER THE NWRN HALF OF THE CWA
ISLTD CONVECTION IS POSSIBLE BUT LOOK FOR MAINLY JUST CLOUDY SKIES.

MON...CONVECTION WILL LIKELY BE MUCH GREATER. MOISTURE FROM THE
TROPICAL WAVE CURRENTLY JUST WEST OF THE FL PENINSULA WILL BEGIN TO
INTERACT WITH THE DECAYING FRONT OVER THE CWA. THE BEST LL
CONVERGENCE WILL SHIFT A TAD NORTH MON AND THIS WILL LEAD TO
CONVECTION POSSIBLY FOCUSING JUST NORTH OF THE COAST WITH PERIODS OF
MODERATE TO HEAVY RAIN LIKELY IMPACTING THE NORTH AND SOUTH SHORES
ALONG WITH THE BTR METRO. /CAB/

LONG TERM...AGAIN MEDIUM RANGE MDLS IN DECENT AGREEMENT WITH AN ERN
CONUS L/W TROUGH DEVELOPING AND GIVING OUR OLD FRONT AN RENEWED PUSH
SOUTH INTO THE GULF DURING THE MIDDLE OF THE WORK WEEK. ON TUE THE
THE FRONT (IF THIS IS ANYTHING LEFT OF IT) WILL LIKELY BE OVER OUR
NRN ZONES AND CONVECTION WILL LIKELY DEPEND MORE ON MESOSCALE
FEATURES I.E. SEA/LAKE BREEZE AND OUTFLOW BNDRYS. OVERALL THERE
SHOULD BE SOME DECENT RAIN TOTALS OVER THE NEXT COUPLE OF DAYS WITH
WIDESPREAD 2-4 INCHES OF RAIN AND ISLTD HIGHER AMOUNTS OCCURRING
FROM TODAY THROUGH TUE. THIS IS ALL HINGING ON THE TROPICAL WAVE NOT
REALLY DEVELOPING INTO MUCH. IF BY SOME WAY THIS WAVE DEVELOPS INTO
A TROPICAL CYCLONE IT WOULD LIKELY PUSH WEST INTO TX AND THUS PULL
THE FRONT FURTHER SOUTH INTO THE GULF WITH DRIER CONTINENTAL AIR
SINKING INTO THE CWA ON TUE AND THUS MUCH LOWER RAIN CHANCES.

IF THE FCST GOES AS CURRENTLY ADVERTISED OUR WAVE IS NOTHING MORE
THAN DEEPER MOISTURE WHICH WILL INTERACT WITH LOWERING HGHTS AS THE
ERN CONUS L/W TROUGH DEEPENS. THIS SHOULD GET SCT CONVECTION OVER
THE REGION WED BUT BY THU AND INTO FRI DRIER AIR SHOULD PUSH INTO
THE AREA AS WE MOVE UNDER NW FLOW. /CAB/

AVIATION...EXPECT SOME PERIODS OF LOW CIGS THIS MORNING AS A
FRONTAL BOUNDARY SAGS SOUTH AND STALLS OVER THE AREA. CIGS SHOULD
BEGIN TO RISE AFTER SUNRISE. EXPECT VFR CONDITIONS TO PREVAIL
THROUGH THE MORNING HOURS BEFORE SHOWERS AND THUNDERSTORMS DEVELOP
THIS AFTERNOON. HAVE INCLUDED VCTS IN ALL SITES THIS AFTERNOON. 13/MH

MARINE...MARINE FCST HAS NOT CHANGED MUCH AS EVERYTHING HANGS ON
THE TROPICAL WAVE OVER THE ERN GULF. LIKE PREVIOUS FCST WILL
CONTINUE TO SHOW A LOW PRESSURE CIRCULATION MOVING ACROSS THE MIDDLE
GULF THROUGH THE WEEKEND INTO EARLY NEXT WEEK...WELL SOUTH OF THE
COASTAL WATERS. WINDS GENRALLY STAY BELOW 15 KNOTS FOR MUCH OF THE
FORECAST PACKAGE GIVEN THE UNCERTAINTIES. THERE REMAINS A SMALL
WINDOW OF OPPORTUNITY FOR SOME DEVELOPMENT IN THE NEXT 24-48 HOUR
PERIOD...BUT CONDITIONS BECOME LESS CONDUCIVE BEYOND THAT TIME
FRAME. NONETHELESS...TIDE LEVELS DUE TO PERSISTENT ONSHORE FLOW WILL
LIKELY INCREASE 1 FOOT ABOVE NORMAL WITH SOME LOCALIZED UP TO 2 FEET
ABOVE NORMAL ALONG EAST FACING SHORES BY SUNDAY EVENING. CAB


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  83  68  89  70 /  40  30  20  20
BTR  83  68  87  72 /  40  30  30  30
ASD  87  72  88  73 /  50  40  50  40
MSY  86  75  88  77 /  50  50  50  40
GPT  89  73  89  75 /  50  40  50  40
PQL  89  71  89  72 /  50  40  50  40

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&

$$








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