FXUS64 KLIX 160053
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
653 PM CST TUE DEC 15 2009
.UPDATE...
.SOUNDING DISCUSSION...
THE ATMOSPHERE IS RELATIVELY MOIST AND STABLE WITH A PRECIPITABLE
WATER VALUE OF 1.36 INCHES AND A LIFTED INDEX VALUE OF 9.6. THE
FRONT HAS PASSED THROUGH MOST OF THE CWA AND A FRONTAL INVERSION
IS PRESENT ON THE SOUNDING NEAR 3000 FEET. WINDS HAVE SHIFTED AND
ARE OUT OF THE NORTH AT THE SURFACE AND OUT OF THE NORTHWEST UP TO
600 MB THEN OUT OF THE SOUTHWEST ALOFT.
&&
.PREV DISCUSSION... /ISSUED 603 PM CST TUE DEC 15 2009/
UPDATE...
HAVE ENDED THE FLASH FLOOD WATCH FOR THE REGION. DRIER AIR IS
MOVING INTO THE AREA...WITH ONLY LIGHTER SHOWERS CURRENTLY OVER
THE SOUTHERN HALF OF THE CWA. THESE LIGHTER SHOWERS SHOULD COME TO
AN END BY LATE THIS EVENING...AS MID-LEVEL DRY AIR ADVECTION
STRENGTHENS. SOME RESIDUAL FLOODING CONTINUES...MAINLY IN AREAS OF
POOR DRAINAGE...BUT EXCESSIVE RAINFALL FOR THE REGION IS NOT
LONGER A THREAT.
PREV DISCUSSION... /ISSUED 420 PM CST TUE DEC 15 2009/
SHORT TERM...
ALTHOUGH THE RAINS HAVE LESSENED...EXCESSIVE RUNOFF AND ONGOING
FLOOD SENSITIVITIES IN SOME MUNICIPALITIES ARE BEING CONSIDERED
FOR THE CONTINUATION OF THE FLASH FLOOD WATCH THROUGH 6 PM. THE
DENSE FOG ADVISORY WILL BE DROPPED AT 6 PM AS WELL AS THE COOLER
AIR FLUSHES THE SEA FOG FROM THE NEAR SHORE WATERS. A MUCH NEEDED
DRY DAY IS IN STORE FOR WEDNESDAY.
LONG TERM...
MODELS CONTINUE TO SHOW A DEVELOPING LOW PRESSURE SYSTEM IN THE
WEST GULF TO PASS BELOW THE LOUISIANA COAST THURSDAY. THIS WILL
BRING A RETURN OF MOSTLY STRATIFORM RAIN OVER LAND AREAS BUT RAIN
AMOUNTS WILL GREATLY DEPEND ON HOW FAR SOUTH THE LOW ACTUALLY
TRACKS. THE GFS SOLUTION PRODUCES ABOUT ONE-HALF INCH ACROSS THE
AREA...WHICH SHOULD NOT POSE MUCH OF A PROBLEM IF RATES STAY IN
THE 0.01 TO 0.05 INCH PER HOUR RANGE. AFTER THE LOW PASSES...MUCH
COLDER AIR GETS DRAWN INTO THE REGION AS THE LOW INDUCES AN ARCTIC
TAP FROM THE NORTHERN BRANCH TROUGH.
AVIATION...
LOW CEILINGS A PATCHY LIGHT RAIN TO LINGER THROUGH ABOUT 03Z THEN
GRADUALLY IMPROVE THROUGH 12Z. IFR CEILINGS SHOULD LIFT TO VFR
AFTER MIDNIGHT FROM NORTHWEST TO SOUTHEAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 39 57 37 53 / 10 0 10 30
BTR 42 58 40 54 / 10 0 10 30
MSY 46 59 46 58 / 20 0 10 50
GPT 45 59 42 59 / 20 0 10 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT WEDNESDAY FOR THE FOLLOWING
ZONES: AND LAKE PONTCHARTRAIN AND LAKE MAUREPAS.
SMALL CRAFT ADVISORY UNTIL 6 PM WEDNESDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL
WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM THE
SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER
ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND COASTAL WATERS
FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER
ATCHAFALAYA RIVER LA OUT 20 NM.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT WEDNESDAY FOR THE FOLLOWING
ZONES: AND LAKE PONTCHARTRAIN AND LAKE MAUREPAS.
SMALL CRAFT ADVISORY UNTIL 6 PM WEDNESDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL
WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM THE
SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER
ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND COASTAL WATERS
FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER
ATCHAFALAYA RIVER LA OUT 20 NM.
&&
$$
