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

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947
FXUS64 KLIX 211756
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1256 PM CDT SAT MAR 21 2015

.AVIATION...

FRONTAL BOUNDARY APPEARS STALLED WELL TO THE NORTH OF KHZR-KMCB AT
THE MOMENT...AND IN THE SHORT TERM THAT IS WHERE THE LOWER CIGS
AND BULK OF THE MORE WIDESPREAD RAIN/SHRA DEVELOPMENT SHOULD
REMAIN THROUGH AT LEAST 21-22Z. ELSEWHERE...CUMULUS CLOUDS ARE
BUILDING...AND ISOLATED TO SCATTERED SHRA AND A FEW TSRA ARE
EXPECTED TO DEVELOP THIS AFTERNOON...BUT HAVE NOT ADDED MENTION IN
THE TAFS UNTIL AFTER ABOUT 22Z WHEN A VCSH IS INCLUDED. TONIGHT
INTO SUNDAY...MORE AREAS ARE LIKELY TO EXPERIENCE SHRA AND
POSSIBLY SOME LOWER MVFR CIGS...AND HAVE INCLUDED THESE LOWER
CONDITIONS AS PREVAILING. 22/TD

&&

.PREV DISCUSSION... /ISSUED 1200 PM CDT SAT MAR 21 2015/

UPDATE...

DID A BRIEF UPDATE TO PUBLIC PRODUCTS TO RAISE HIGH TEMPERATURES
ACROSS THE SOUTHEAST HALF OF THE CWA...WHERE A COUPLE MORE HOURS
OF SUNSHINE ARE POSSIBLE. EXPECT THOSE AREAS TO SNEAK INTO THE
LOWER 80S. DID NOT MAKE CHANGES TO RAIN CHANCES AS PRECIPITATION
SHIELD JUST WEST OF THE CWA. DID USE LATE AFTERNOON WORDING FOR
PRECIPITATION ACROSS THE SOUTHEAST HALF OF THE AREA. 35

PREV DISCUSSION... /ISSUED 801 AM CDT SAT MAR 21 2015/

SOUNDING DISCUSSION...

SOUNDING DATA IS IN. PW A TAD HIGHER AT 1.52 INCHES WITH WINDS
SHIFTING FROM THE EAST TO THE WEST BY 5KFT. MOISTURE JET ABOVE
50KT PEAKING AT 85KT AT 38KFT. EASILY REACH CONVECTIVE TEMPS
TODAY. LIFTING A PARCEL AT FORECAST AFTERNOON TEMPERATURES GIVE
CAPE VALUES AROUND 700 J/KG AND LCL AT 1346M. SOME LOW LEVEL SHEAR
BELOW 5KFT. ENVIRONMENT DOES NOT SUPPORT WIDESPREAD SEVERE WEATHER
HOWEVER SOME THUNDERSTORMS COULD PRODUCE SOME GUSTY WINDS AND
HEAVY RAIN.

PREV DISCUSSION... /ISSUED 416 AM CDT SAT MAR 21 2015/

SHORT TERM...
FAIRLY QUIET MORNING ACROSS THE FORECAST AREA. FOG HAS BEEN SLOW
TO FORM THIS MORNING BUT WILL CONTINUE TO KEEP IT IN THE FORECAST
THROUGH THE EARLY MORNING HOURS. THE BIG WEATHER MAKER IS AN UPPER
LOW OVER NORTHERN MEXICO THAT WILL KICK OUT OVER THE SOUTHERN
PLAINS THIS WEEKEND. AT THE SURFACE LOW PRESSURE WILL DEVELOP AND
MOVE ACROSS THE FORECAST AREA ON SUNDAY. CURRENTLY THE RADAR OVER
NORTHWEST LOUISIANA AND MOST OF SOUTHEAST TEXAS IS FAIRLY BUSY
WITH PLENTY OF RAIN. THIS COULD BE A PRETTY DECENT RAIN EVENT FOR
NORTHWEST LOUISIANA...SOUTHEAST TEXAS AND ALONG THE INTERSTATE
20/59 CORRIDOR AS MOST OF THE HEAVIER RAINFALL SHOULD REMAIN NORTH
OF OUR AREA.

LOCALLY A STALLED BOUNDARY IS LOCATED JUST OFF THE LOUISIANA
COAST THIS MORNING AND THIS BOUNDARY WILL BE INFLUENCED BY THE
DEVELOPING SYSTEM ACROSS TEXAS AND LIFT BACK NORTH TODAY AS A WARM
FRONT. THE WARM FRONT AS IT MOVES NORTH TODAY COULD KICK OFF A FEW
SHOWERS AND THUNDERSTORMS. WILL CONTINUE TO CARRY SLIGHT CHANCE TO
CHANCE POPS FOR MOST OF THE DAY TODAY WITH THE CHANCE OF RAIN
INCREASING IN THE AFTERNOON HOURS INTO THE EVENING. QUITE FRANKLY
IT LOOKS LIKE MOST OF THE MORNING AND EARLY AFTERNOON HOURS
SHOULD BE RELATIVELY DRY FOR MOST OF THE AREA WITH THE EXCEPTION
OF THE FAR NORTHWESTERN PORTIONS OF OUR FORECAST AREA. THE RAIN
CHANCES CONTINUE TO INCREASE TONIGHT AS THE SURFACE LOW CONTINUES
TO PUSH EAST. IT LOOKS LIKE THE EVENING HOURS COULD BE QUIET AS
WELL AFTER THE INITIAL PUSH WITH THE WARM FRONT THIS AFTERNOON.
THE BEST CHANCES FOR RAINFALL TONIGHT WILL COME AFTER MIDNIGHT
AND MORE SO ON SUNDAY AS THE SURFACE LOW MOVES ACROSS THE REGION.
WE ARE NOT EXPECTING ALL DAY RAINS WITH THIS EVENT...AND WILL
CONTINUE TO CARRY HIGH POPS FOR CONFIDENCE AND NOT NECESSARILY FOR
COVERAGE THIS WEEKEND. ANOTHER INTERESTING THING TO NOTE IS THAT
THE STORM PREDICTION CENTER HAS NOW HIGHLIGHTED OUR AREA IN A
MARGINAL RISK FOR SEVERE WEATHER ON SUNDAY AS THE SURFACE LOW
MOVES ACROSS THE REGION. THE ATMOSPHERE SHOULD BE A LITTLE BIT
MORE CONDUCIVE FOR DEEPER CONVECTION. THIS DOES NOT LOOK LIKE A
CLASSIC SEVERE WEATHER SETUP BUT SOME OF THE STORMS IF THEY
DEVELOP COULD BE FAIRLY STRONG AND POSSIBLY REACH SEVERE STATUS ON
SUNDAY. WILL HAVE TO WATCH THIS ASPECT OF THE FORECAST...BUT THE
MAIN THREAT WITH THE DEEPER CONVECTION WILL BE HEAVY RAIN AND
GUSTY WINDS. THE SYSTEM SHOULD MOVE OUT OF THE AREA LATE SUNDAY
NIGHT INTO MONDAY MORNING. 13/MH

LONG TERM...
WE SHOULD DRY OUT EARLY NEXT WEEK THROUGH AT LEAST WEDNESDAY.
TEMPERATURES SHOULD BE BACK AROUND SEASONAL NORMALS OR SLIGHTLY
ABOVE AND IT SHOULD NOT FEEL AS MUGGY AS SOME SLIGHTLY DRIER AIR
SHOULD MOVES IN MONDAY. AFTER WEDNESDAY MODELS STILL CONTINUE TO
HAVE A HARD TIME WITH THE NEXT NORTHERN STREAM FEATURE AND IF A
COLD FRONT MAKES IT DOWN INTO THE FORECAST AREA IN THE
THURSDAY/FRIDAY TIME FRAME. WILL HAVE TO CONTINUE TO WATCH THIS
FEATURE. HAVE NOT MADE MANY CHANGES IN THE LONG RANGE FORECAST
THIS MORNING. HAVE CONTINUED TO USE A BLEND OF GUIDANCE. 13/MH

AVIATION...
FOG HAS YET TO MATERIALIZE AT TAF LOCATIONS AS NEARBY
WATER TEMPERATURES HAVE WARMED CONSIDERABLY THE PAST SEVERAL
DAYS...THEREBY OFFERING LESS FAVORABLE CONDITIONS FOR FOG
DEVELOPMENT. SOME LIGHT FOG MAY STILL BE POSSIBLE BY DAYBREAK...BUT
MODERATE LOW LEVEL WINDS MAY MAINTAIN A STRATUS DECK THAT SHOULD
LIFT ADIABATICALLY WITH DAYTIME HEATING THROUGH MVFR CIGS THIS
MORNING THEN LOW END VFR BASES THIS AFTERNOON. 24/RR

MARINE...
SURFACE HIGH PRESSURE OVER THE EASTERN GULF OF MEXICO IS
MAINTAINING RELATIVELY LIGHT WINDS AND LOW SEAS OVER THE NORTH GULF.
MEANWHILE...A COLD FRONT DRAPED ACROSS CENTRAL LOUISIANA INTO
LOWER TEXAS WILL BE SLOWLY MOVING INTO THE NORTH GULF SUNDAY
EVENING. WINDS WILL SHIFT TO NORTHWESTERLY AT MODERATE LEVELS
SUNDAY NIGHT BEFORE SETTLING TO LIGHTER LEVELS WHILE VEERING
MONDAY INTO MONDAY NIGHT. ONSHORE FLOW THEN PREVAILS UNTIL A MUCH
STRONGER COLD FRONT MOVES INTO THE NORTH GULF FRIDAY. 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 TONIGHT RISK SVR
         AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
         SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  77  62  73  56 /  80  80  80  60
BTR  79  65  77  58 /  70  70  80  30
ASD  81  66  76  60 /  70  70  80  60
MSY  82  66  77  61 /  60  60  80  40
GPT  80  65  75  61 /  60  60  80  60
PQL  81  65  75  61 /  60  70  80  60

&&

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

$$



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