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

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977
FXUS64 KLIX 162047
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
347 PM CDT THU APR 16 2015

.SYNOPSIS...


SURFACE HIGH PRESSURE RESIDES ALONG THE EAST COAST THIS AFTERNOON
WITH LOW PRESSURE IN NEW MEXICO. CONVECTIVE COMPLEX WELL SOUTHEAST
OF THE LOUISIANA COAST APPARENTLY CUT OFF OUR BEST INFLOW AND HAS
KEPT SOUTHEAST LOUISIANA DRIER THAN ANTICIPATED...ALTHOUGH CLOUDY.
SCATTERED CONVECTION CURRENTLY OCCURRING OVER SOUTHWEST
MISSISSIPPI...AND CONSIDERABLY MORE CONVECTION OCCURRING ACROSS
SOUTHWEST LOUISIANA. TEMPERATURES HAVE REMAINED IN THE 70S TODAY
WITH DEW POINTS IN THE UPPER 60S AND LOWER 70S.

&&

.SHORT TERM...

WILL CONTINUE FLASH FLOOD WATCH IN ITS CURRENT CONFIGURATION.
MESOSCALE MODELING INDICATES THAT PRECIPITATION OVER SOUTHWEST
LOUISIANA WILL MAKE ITS WAY INTO OUR AREA THIS EVENING. WHILE THE
HEAVY RAINFALL THREAT IS NOT AS HIGH TONIGHT AS THE LAST COUPLE OF
DAYS...IT CERTAINLY IS NOT ZERO. BUFR SOUNDING DATA SHOWS
PRECIPITABLE WATER VALUES REMAINING HIGH...IN EXCESS OF 1.75
INCHES...OVER THE AREA. NEXT IMPULSE ARRIVES TOMORROW AFTERNOON OR
EARLY EVENING...AND EXPECT DEVELOPMENT OF MORE THUNDERSTORMS. NOTE
SOME DRIER AIR IN THE FORECAST SOUNDINGS BETWEEN 500 AND 700 MB
TOMORROW WHICH MAY ENHANCE THE SEVERE WEATHER THREAT SOMEWHAT.
OTHER IMPULSES MOVE THROUGH THE FORECAST AREA ON SATURDAY AND
SUNDAY...BRINGING A REPEAT OF THE SHOWERS AND THUNDERSTORMS
SATURDAY. SOME INDICATIONS THAT THE SUNDAY IMPULSE MAY NOT HAVE
AS MUCH MOISTURE TO WORK WITH...AFTER THE PASSAGE OF THE SATURDAY
ONE. NO REAL DEFINED FOCUSING MECHANISM SUCH AS A FRONTAL BOUNDARY
TO PINPOINT THE BEST THREAT AREA EACH DAY. WILL CONTINUE WITH
LIKELY TO CATEGORICAL POPS INTO SUNDAY FOR MUCH OF THE AREA.
TEMPERATURES WILL GENERALLY REMAIN IN THE 70S FOR HIGHS UNLESS A
FEW BREAKS IN THE CLOUDS OCCUR...WHICH WOULD ALLOW READINGS TO
CREEP INTO THE LOWER 80S. 35

&&

.LONG TERM...

MODELS IN FAIRLY DECENT AGREEMENT ON THE POTENTIAL TO SWEEP DEEP
MOISTURE OUT OF THE AREA BY SUNDAY EVENING. WILL GO WITH THE LOWER
POPS THAT THE MEDIUM RANGE MODELS INDICATE FOR EARLY IN THE WEEK.
GENERALLY ZONAL FLOW FOR EARLY IN THE WEEK WITH MOST IMPULSES
PASSING TO OUR SOUTH. WILL CARRY SMALL CHANCES FOR RAIN ON
THURSDAY AS A NEW SYSTEM APPROACHES FROM THE WEST.

THE DRIER AIR SHOULD ALLOW FOR LARGER DIURNAL RANGES WITH LOW
TEMPERATURES A LITTLE COOLER THAN WHAT WE HAVE SEEN THE LAST FEW
DAYS...AND HIGH TEMPERATURES ABOUT 5 DEGREES ABOVE NORMAL. 35

&&

.AVIATION...

TAFS WILL BE DEPENDENT ONCE AGAIN ON THE PROGRESSION OF SHOWERS
AND THUNDERSTORMS THIS AFTERNOON. LATEST RADAR TRENDS SHOW A LARGE
SWATH OF SHOWERS WITH ISOLATED THUNDERSTORMS MOVING EAST FROM
SOUTH CENTRAL LA. MOST TERMINALS NORTH OF HUM AND MSY WILL SEE
LIGHT TO MODERATE THROUGH THE EVENING HOURS ALONG WITH MVFR TO IFR
CIGS. AFTER THAT...LOWER CLOUDS LIKELY TO DEVELOP ALONG WITH LIGHT
TO MODERATE FOG. IFR TO LIFR CONDITIONS POSSIBLE AGAIN TOMORROW
MORNING.

MEFFER

&&

.MARINE...

EXPECT TO SEE AN ONSHORE FLOW OF 10 TO 15 KNOTS REMAIN OVER THE
COASTAL WATERS THROUGH FRIDAY. AS AN UPPER LEVEL LOW AND
ASSOCIATED WEAK SURFACE LOW AND FRONT MOVE THROUGH OVER THE
WEEKEND...WINDS WILL INCREASE TO RIGHT AT EXERCISE CAUTION RANGE
SATURDAY BUT NOT REALLY SURPASS THAT THRESHOLD TILL THE OVERNIGHT
PERIOD OVER THE OFFSHORE WATERS. THOSE CONDITIONS SHOULD PERSIST
INTO SUNDAY BEFORE FADING DURING THE LATE AFTERNOON HOURS. SEAS
WILL RESPOND AND INCREASE TO 3 TO 5 FEET IN THE OFFSHORE WATERS.
THE GRADIENT WILL CONTINUE TO EASE OVER THE AREA ON
MONDAY...ALLOWING FOR WEAKER AND MORE VARIABLE FLOW OF 10 KNOTS OR
LESS. SEAS WILL ALSO FALL BACK INTO THE 1 TO 3 FEET RANGE FOR
MONDAY AND TUESDAY.

MEFFER

&&

.DECISION SUPPORT...

DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING HEAVY RAINFALL/FLOODING POTENTIAL
             ASSESSING SEVERE WEATHER THREAT THRU WEEKEND.

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  65  79  66  78 /  60  60  60  80
BTR  67  82  68  79 /  70  70  70  80
ASD  68  81  68  79 /  70  70  70  80
MSY  69  82  70  79 /  70  70  70  80
GPT  69  78  70  77 /  70  70  70  80
PQL  68  81  70  78 /  70  70  70  80

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR LAZ040-046>050-
     056>070-072.

GM...NONE.
MS...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR MSZ077-080>082.

GM...NONE.
&&

$$



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