000
FXUS64 KLIX 200915
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
415 AM CDT SAT MAR 20 2010
.SHORT TERM...
A RAPIDLY DEEPENING UPPER LEVEL TROUGH CURRENTLY OVER THE SOUTHERN
ROCKIES WILL CONTINUE TO PULL TO THE EAST TONIGHT INTO TOMORROW.
AS THE UPPER LEVEL TROUGH MOVES TO THE EAST...A STRONG SURFACE LOW
WILL DEVELOP OVER THE SOUTHERN PLAINS AND MOVE INTO THE MID-
MISISSIPPI VALLEY BY SATURDAY EVENING. AS THE UPPER LEVEL SYSTEM
DEEPENS...COLD AIR OVER THE NORTHERN PLAINS WILL BE DRAWN
SOUTHWARD INTO THE SOUTHERN PLAINS AND TEXAS. THE UPPER LEVEL
SYSTEM WILL BEGIN TO TAKE ON A MORE NEGATIVE TILT TOMORROW
NIGHT...ALLOWING THE SURFACE COLD FRONT TO RAPIDLY SWEEP EASTWARD
ACROSS THE FORECAST AREA. THE UPPER LEVEL LOW AND SURFACE LOW
SHOULD BECOME VERTICALLY STACKED BY THIS POINT.
THUNDERSTORM DEVELOPMENT IS EXPECTED ALONG THE FRONT...BUT AN
OVERALL LACK OF LOW LEVEL INSTABILITY WILL GREATLY LIMIT THE
CHANCES FOR SEVERE WEATHER TOMORROW NIGHT. AFTER LOOKING AT THE
LATEST MODEL SOUNDINGS...THE BEST LAPSE RATES WILL BE FOUND ABOVE
850MB. THIS WOULD SUPPORT THE DEVELOPMENT OF HAIL...BUT THE RISK
OF STRONG WINDS AND TORNADOES WILL BE GREATLY LIMITED.
IN THE WAKE OF THE FRONT...THE VERTICALLY STACKED AND SLOWLY
MOVING UPPER LEVEL LOW WILL CONTINUE TO BRING CLOUDS AND SCATTERED
SHOWERS TO THE NORTHERN HALF OF THE CWA THROUGH SUNDAY NIGHT.
HOWEVER...STRONG COLD AIR ADVECTION ASSOCIATED WTIH THE UPPER
LEVEL TROUGH WILL DROP TEMPERATURES A GOOD 20 DEGREES BELOW NORMAL
SUNDAY INTO SUNDAY NIGHT. OVERALL...1000-500MB THICKNESSES ARE
EXPECTED TO DROP TO AROUND 5400 METERS AS FAR SOUTH AS THE NEW
ORLEANS AREA ON SUNDAY. FORTUNATELY...SURFACE TEMPERATURES WILL
BE WARM ENOUGH TO KEEP ALL PRECIPITATION IN THE LIQUID FORM.
THICKNESSES WILL BEGIN TO INCREASE LATE SUNDAY NIGHT INTO MONDAY
AS THE MAIN UPPER LEVEL LOW PULLS INTO THE MID-ATLANTIC STATES. IN
ADDITION TO THE COLDER THAN NORMAL TEMPERATURES...STRONG WINDS
ALOFT SHOULD MIX DOWN SATURDAY NIGHT INTO SUNDAY. THESE STRONG
WINDS COULD LEAD TO A POSSIBLE WIND ADVISORY FOR SUNDAY.
.LONG TERM...
HEADING INTO THE REMAINDER OF NEXT WEEK...A BROAD UPPER LEVEL
RIDGE IS EXPECTED TO BUILD IN MONDAY NIGHT INTO TUESDAY AND REMAIN
IN PLACE THROUGH WEDNESDAY. THIS STRONG UPPER LEVEL RIDGING WILL
ALLOW FOR CLEAR SKIES AND A RETURN TO MORE NORMAL TEMPEATURE
READINGS. HOWEVER...ANOTHER UPPER LEVEL TROUGH IS EXPECTED TO
AFFECT THE REGION THURSDAY INTO THURSDAY. BOTH THE GFS AND ECMWF
ARE IN GOOD AGREEMENT ON THE TIMING AND STRENGTH OF THIS NEXT
SYSTEM...AND HAVE FAIRLY DECENT CONFIDENCE WITH THIS EVENT. THIS
SYSTEM WILL BE MORE PACIFIC IN NATURE...WITH LITTLE IN THE WAY OF
COLD AIR ADVECTION EXPECTED BEHIND THE FRONT THURSDAY NIGHT. IN
ADDITION...WITH LESS OVERALL FORCING...EXPECT LESS PRECIP
COVERAGE. THE UPPER LEVEL PATTERN SHOULD TURN MORE ZONAL AFTER
THIS UPPER LEVEL TROUGH MOVES...WITH NEAR NORMAL TEMPERATURES AND
DRY CONDITIONS EXPECTED FRIDAY AND SATURDAY.
&&
.AVIATION...OVERALL NOT EXPECTING MUCH IN THE WAY OF PROBLEMS FOR
THE TAF SITES BUT REDUCED VISBIES COULD OCCUR DURING THE EARLY
MORNING HRS. WINDS SHOULD START TO INCREASE MAINLY JUST ABV THE SFC
AND THIS WILL LIKELY KEEP THINGS MIXED WELL ENOUGH TO KEEP VISBIES
FROM DROPPING BELOW MVFR IF THEY EVEN FALL THAT FAR. BY THIS EVN
THINGS WILL BEGIN TO CHANGE AS INCREASING MOISTURE AND THE APPROACH
OF A STRONG COLD FRONT WILL LEAD TO LOWERING CIGS AND EVENTUALLY
SHRA AND ISLTD TSRA. WINDS WILL ALSO BE ON THE INCREASE...ESPECIALLY
AFTER THE FRONTAL PASSAGE WHICH WILL OCCUR ACROSS THE CWA B/T 3Z AND
9Z SUN. /CAB/
&&
.MARINE...THINGS WILL BEGIN TO CHANGE QUICKLY TODAY. AS THE WRN
PLAINS DISTURBANCE DROPS INTO THE SRN PLAINS AND DEEPENS. THIS WILL
AID IN CYCLOGENESIS OCCURRING ACROSS THE LOWER MS VALLEY TODAY AND
THIS WILL START TO TIGHTEN THE PRESSURE GRADIENT THIS AFTN ACROSS
THE AREA. THIS WILL CAUSE SRLY WINDS TO INCREASE TO AROUND 15-20KT
SO WE WILL START SCS HEADLINES AROUND MIDDAY. THE MAIN SFC LOW WILL
DEVELOP OVER NE AR AND THIS WILL PUSH A STRONG COLD FRONT THROUGH
THE AREA RATHER QUICKLY TONIGHT AND SHOULD BE COMPLETELY THROUGH THE
COASTAL WATERS NO LATER THAN 9Z. ON THE BACK SIDE OF THE FRONT WINDS
WILL VEER AROUND TO THE WNW AND WITH SFC PRESSURE RISES ON THE ORDER
OF 4-6MB IN 6 HRS WINDS WILL QUICKLY RAMP UP. ADD IN RATHER STRONG
CAA IN THE LL ALONG WITH WINDS QUICKLY BECOMING UNIDIRECTIONAL FROM
THE SFC TO H85 WE WILL HAVE THE RECIPE FOR VERY STRONG WINDS DURING
THE EARLY MORNING HRS AND THROUGH MUCH OF THE DAY SUN. MDLS ARE
SUGGESTING WINDS OF 35 TO 50KTS AROUND H925 AND H85 AND THESE WINDS
SHOULD HAVE NO PROBLEM MIXING DOWN TO THE SFC AS GUSTS. WITH
FREQUENT GUSTS(POSSIBLY EVEN SUSTAINED WINDS AT TIMES) AT AND ABV
35KTS WE WILL GO AHEAD WITH A GALE WATCH FROM 9Z SUN MORNING TILL
21Z SUN. THIS WATCH WILL LIKELY NEED TO BE UPGRADED TO A WARNING
TODAY AND MAY EVEN NEED TO BE EXTENDED INTO THE EVN HRS SUN. WINDS
WILL THEN BEGIN TO SLACK OFF SUN NIGHT AND MORE SO ON MON AS THE
BROAD SFC LOW LIFTS OFF TO THE ENE AND HIGH PRESSURE BUILDS BACK
INTO THE GULF. SEAS WILL OF COURSE ALSO BE AN ISSUE AND THE OUTER
WATERS COULD SEE SEAS AROUND 9-11FT DURING THE EARLY MORNING AND
MIDDAY HRS SUN. THE TIDAL LAKES COULD NEED A GALE WARNING BUT AT
THIS TIME WE WILL STICK WITH A SCY FROM 9Z SUN THROUGH 12Z MON. ON
ANOTHER NOTE...THE VERY STRONG WINDS WE SAW MAR 1ST ASSOCIATED WITH
A WAKE LOW...WE ARE NOT EXPECTING THE SAME THING TO OCCUR. THERE
WONT BE A RAPIDLY DEEPENING SFC LOW MOVING ACROSS THE COAST OR A
DECENT AREA OF DEEP CONVECTION MOVING ACROSS SERN LA WHICH AIDED IN
THAT DEVELOPING BUT THOSE TYPES OF MESOSCALE FEATURES ARE VERY HARD
IF NOT NEAR IMPOSSIBLE TO COMPLETELY PREDICT. THAT SAID WINDS WILL
BE RATHER GUSTY ACROSS THE ENTIRE AREA...LAND INCLUDED ON SUN. /CAB/
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 71 39 49 33 / 20 80 30 30
BTR 74 39 52 35 / 20 80 20 20
ASD 71 43 53 35 / 10 80 20 20
MSY 71 42 54 40 / 10 80 10 10
GPT 69 45 55 38 / 10 80 20 20
PQL 70 52 56 37 / 10 80 20 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY FROM 7 PM SATURDAY TO 4 AM SUNDAY 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.
GALE WATCH FROM 4 AM SUNDAY TO 4 PM SUNDAY 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.
SMALL CRAFT ADVISORY FROM 4 PM SUNDAY TO 7 AM MONDAY 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.
SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 7 AM MONDAY FOR THE
FOLLOWING ZONES: AND LAKE PONTCHARTRAIN AND LAKE MAUREPAS.
MS...NONE.
GM...SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 7 AM MONDAY FOR THE
FOLLOWING ZONES: AND LAKE PONTCHARTRAIN AND LAKE MAUREPAS.
GALE WATCH FROM 4 AM SUNDAY TO 4 PM SUNDAY 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.
SMALL CRAFT ADVISORY FROM 7 PM SATURDAY TO 4 AM SUNDAY 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.
SMALL CRAFT ADVISORY FROM 4 PM SUNDAY TO 7 AM MONDAY 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.
&&
$$
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