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

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FXUS64 KLIX 300056
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
756 PM CDT TUE JUL 29 2014

...SOUNDING DISCUSSION...

A DRY AIRMASS IN PLACE WITH PRECIPITABLE WATER VALUES SAMPLED AT
1.21 INCHES...WHICH IS 2 STANDARD DEVIATION BELOW NORMAL FOR THIS
TIME OF YEAR. THE DRIER AIR IS ALSO QUITE EVIDENT WHEN YOU WALK
OUT THE DOOR WITH THE TEMPERATURE-DEWPOINT SPREAD BEING AROUND 10
THIS EVENING AT THE SURFACE. THE MID-LEVELS ARE ALSO QUITE DRY BETWEEN
800MB AND 550MB AND THERE IS A TEMPERATURE INVERSION IN THE
800-750MB LEVEL AS WELL. COMPARED TO 24 HOURS AGO...THE
TEMPERATURE IS LOWER /COOLER/ BELOW 800MB AND THEN LITTLE CHANGE
ABOVE THE 800MB LEVEL. WINDS WERE GENERALLY FROM THE NORTH AND
NORTHWEST THROUGHOUT THE SOUNDING AND THE MAXIMUM WIND SPEED OF 42
KNOTS WAS LOCATED 7.8 MILES. TONIGHT/S BALLOON TERMINATED OVER
EASTERN LAKE PONTCHARTRAIN WHERE IT BURST AT A HEIGHT OF 20.7
MILES ABOVE THE GROUND.

ANSORGE

&&

.PREV DISCUSSION... /ISSUED 330 PM CDT TUE JUL 29 2014/

SHORT TERM...

THROUGH TOMORROW...A DRY AND VERY STABLE AIRMASS WILL DOMINATE THE
REGION AS A BROAD SURFACE HIGH CENTERED OVER THE SOUTHEASTERN
CONUS REMAINS IN PLACE. AS A RESULT...EXPECT MOSTLY CLEAR SKIES
AND VERY MILD CONDITIONS ACROSS THE FORECAST AREA. DAYTIME HIGHS
WILL RUN AROUND 5 DEGREES BELOW NORMAL AND OVERNIGHT LOWS WILL BE
A GOOD 10 DEGREES BELOW AVERAGE FOR LATE JULY.

THE DRY WEATHER WILL COME TO AND ON THURSDAY...AS A VORT MAX
SLIDES DOWN THE BACKSIDE OF A STRONG LONG WAVE TROUGH PARKED
OVER THE EASTERN THIRD OF THE CONUS. THIS VORT MAX AND AN
ASSOCIATED FRONTAL BOUNDARY WILL SLIDE INTO THE REGION EARLY
THURSDAY AND THEN TURN STATIONARY ALONG THE GULF COAST AS THE
PARENT UPPER LEVEL TROUGH BEGINS TO LIFT TO THE NORTH AND EAST.
THIS LOW LEVEL BOUNDARY...COMBINED WITH A BROAD AREA OF HIGHER
OMEGA ASSOCIATED WITH THE LOBE OF UPPER LEVEL VORTICITY WILL SERVE
AS A FOCUS FOR CONVECTIVE ACTIVITY BEGINNING THURSDAY AFTERNOON
AND PERSISTING INTO FRIDAY. HAVE BUMPED POPS TO LIKELY...AS
CONFIDENCE IN THE FRONT STALLING OVER THE REGION HAS INCREASED.

LONG TERM...

THE LONG WAVE TROUGH LINGER OVER THE EASTERN THIRD OF THE NATION
THROUGH THE WEEKEND...AND THE FRONTAL BOUNDARY WILL CONTINUE TO
SIT OVER THE FORECAST AREA...THOUGH IT WILL GRADUALLY TURN MORE
DIFFUSE WITH EACH PASSING DAY. HAVE LOWERED POPS SLIGHTLY FOR
SATURDAY AND SUNDAY FROM AROUND 50 PERCENT TO 30 PERCENT BY SUNDAY
AS THE FRONTAL BOUNDARY WASHES OUT AND THE LOW LEVEL FOCUS FOR
CONVECTIVE ACTIVITY WANES. HOWEVER...THERE WILL CONTINUE TO BE A
HIGHER THAN AVERAGE CHANCE OF RAIN EACH DAY DUE TO THE CONTINUED
UPPER LEVEL SUPPORT FROM THE TROUGH AND WEAK VORTICITY MAXIMA
SLIPPING THROUGH THE AREA.

THE UPPER LEVEL TROUGH WILL FINALLY BEGIN TO LIFT OUT OF THE AREA
ON MONDAY AND TUESDAY...BUT A REGION OF CUT OFF VORTICITY WILL
LINGER OVER THE GULF SOUTH THROUGH TUESDAY. THIS WEAK AREA OF
FORCING WILL CONTINUE TO KEEP CHANCE POPS IN PLACE BOTH DAYS. THE
CONVECTION WILL BE MUCH MORE DIURNAL IN NATURE...WITH THE GREATEST
RISK OCCURRING FROM LATE MORNING THROUGH THE AFTERNOON HOURS.
EXPECT TO SEE COVERAGE OF CONVECTION BE GREATER DURING THE
OFFSHORE WATERS DURING THE OVERNIGHT HOURS. AS THE SEABREEZE
DEVELOPS EACH DAY...CONVECTION WILL DEVELOP ALONG THIS MESOSCALE
BOUNDARY AND THEN FURTHER CONVECTION WILL SPARK OFF THE RESULTANT
OUTFLOW BOUNDARIES. THIS PATTERN WILL BASICALLY BE THE NORMAL
SUMMER ROUTINE OF AFTERNOON CONVECTION...BUT WITH SOME INCREASED
UPPER LEVEL SUPPORT TO KEEP THE CONVECTION GOING LONGER THAN
NORMAL.

AVIATION...

DRIER AIR WILL CONTINUE TO FILTER IN FROM THE NORTH AND KEEP
CONDITIONS VFR THROUGH WEDNESDAY. 22/TD

MARINE...

WINDS WILL GENERALLY BE 10 KNOTS OR LESS OVER THE COASTAL WATERS
THROUGH THE FORECAST PERIOD. THE WINDS WILL BE HIGHLY VARIABLE
THROUGH THURSDAY AS A FRONTAL BOUNDARY WASHES OUT OVER THE COASTAL
WATERS. ON FRIDAY AND CONTINUING THROUGH THE WEEKEND...WINDS WILL
TURN MORE SOUTHERLY...AND SHOULD REMAIN FROM THE SOUTH.
OVERALL...NO SIGNIFICANT IMPACTS TO THE BOATING COMMUNITY OUTSIDE
OF CONVECTION ARE EXPECTED THROUGH EARLY NEXT WEEK.

DECISION SUPPORT...

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  64  88  65  87 /   0  10  20  40
BTR  66  89  66  90 /   0  10  20  40
ASD  65  89  65  88 /   0  10  20  40
MSY  72  88  72  88 /   0  10  10  40
GPT  66  91  67  89 /   0  10  10  40
PQL  64  87  63  89 /   0  10  10  40

&&

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

$$







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