FXUS64 KLIX 242253 AAA
AFDLIX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NEW ORLEANS LA
453 PM CST THU DEC 24 2009
.UPDATE...
BRIEF UPDATE OF ZFP AND CWF TO REMOVE MENTION OF TORNADO WATCH. NO
SIGNIFICANT CHANGES OTHERWISE. ANTICIPATE ANOTHER UPDATE AT 9 PM
TO DEAL WITH COASTAL FLOOD ADVISORY AND PRECIPITATION TRENDS. 35
&&
.PREV DISCUSSION... /ISSUED 340 PM CST THU DEC 24 2009/
SHORT TERM...
A VIGOROUS LOW CURRENTLY PULLING INTO THE ARKLATEX WILL CONTINUE
TO BE THE MAIN WEATHER FEATURE OF NOTE THROUGH TOMORROW MORNING.
AS THE LOW PULLS TO THE NORTHEAST...DRIER AND COLDER AIR WILL BE
DRIVEN SOUTHEASTWARD INTO THE LOWER MISSISSIPPI VALLEY. AS A
RESULT...EXPECT CLEARING SKIES LATE TONIGHT INTO CHRISTMAS MORNING
AND MUCH COLDER TEMPERATURES BY DAYBREAK. WINDS WILL REMAIN QUITE
STRONG...AS THE DEEP SURFACE LOW AND HIGH PRESSURE TO THE EAST AND
SOUTH CONTINUE TO PRODUCE A TIGHT GRADIENT ACROSS THE REGION.
WINDS WILL CONTINUE TO GUST TO AROUND 25 MPH THROUGH THE
NIGHT..BUT WINDS WILL BE FROM THE WEST INSTEAD OF THE SOUTH.
HIGH PRESSURE WILL THEN SETTLE OVER THE REGION FRIDAY NIGHT...AS
THE LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST. A LIGHT FREEZE IS
EXPECTED NORTH OF THE LAKE FRIDAY NIGHT...ALONG WITH CLEAR
SKIES...LOW HUMIDITIES...AND LIGHT WINDS. THE HIGH WILL QUICKLY
TRANSITION TO THE EAST ON SATURDAY...AS A WEAK UPPER LEVEL VORT
MAX SWINGS INTO THE WESTERN GULF OF MEXICO. IN A REGION OF
ENHANCED BAROCLINICITY OVER THE WESTERN GULF...THE EXTRA LIFT
PROVIDED BY THE UPPER LEVEL VORT MAX WILL ALLOW FOR THE FORMATION
OF A WEAK GULF LOW. THIS GULF LOW WILL QUICKLY SWEEP TO THE
NORTHEAST. AT THIS TIME...THERE IS SOME UNCERTAINTY ON THE AMOUNT
OF MOISTURE RETURN THAT WILL TAKE PLACE AHEAD OF THIS SYSTEM
SATURDAY INTO SATURDAY NIGHT.
BOTH THE NAM AND GFS BRING THE LOW THROUGH THE NORTHERN GULF OF
MEXICO SATURDAY NIGHT. THE ECMWF IS A BIT FURTHER SOUTH AND MUCH
WEAKER WITH THE AREA OF LOW PRESSURE. AT THIS TIME...HAVE WENT
WITH A BLEND OF THE NAM AND GFS. INITIALLY...STRONG SOUTHWEST FLOW
IN THE MID AND UPPER LEVELS WILL OVERRUN A COLDER AND MORE STABLE
AIRMASS AT THE SURFACE. INCREASING CLOUDS CAN BE EXPECTED SATURDAY
AS MOISTURE BUILDS DOWN FROM THE UPPER LEVELS. BY SATURDAY
NIGHT...THE MOISTURE SHOULD BE SUFFICIENT ENOUGH TO PRODUCE
SCATTERED LIGHT RAIN SHOWERS ACROSS SOUTHEAST LOUISIANA AND
SOUTHERN MISSISSIPPI. AFTER REVIEWING MODEL SOUNDINGS...IT APPEARS
THAT THE PRECIP SHOULD REMAIN LIQUID. HOWEVER...IF THE AIRMASS IS
A BIT DRIER OR COLDER THAN EXPECTED...SOME WINTRY PRECIP COULD MIX
IN OVER SOUTHWEST MISSISSIPPI AND NORTHERN PORTIONS OF THE FLORIDA
PARISHES. THIS SITUATION WILL HAVE TO BE MONITORED OVER THE NEXT
COUPLE OF DAYS.
LONG TERM...
HIGH PRESSURE IS EXPECTED TO BUILD BACK OVER THE REGION SUNDAY
INTO SUNDAY NIGHT...AS THE GULF LOW QUICKLY PULLS TO THE EAST AND
INTO THE SOUTHEASTERN STATES. THIS AREA OF HIGH PRESSURE WILL
REMAIN IN PLACE THROUGH TUESDAY WITH CLEAR SKIES AND COLDER THAN
NORMAL TEMPERATURES EXPECTED. ONCE AGAIN...A LIGHT FREEZE WILL BE
POSSIBLE SUNDAY AND MONDAY NIGHTS ACROSS MOST OF THE
AREA...EXCLUDING COASTAL LOUISIANA AND THE SOUTHSHORE OF LAKE
PONTCHARTRAIN.
UNFORTUNATELY...THE PATTERN WILL ONCE AGAIN TURN UNSETTLED TUESDAY
NIGHT...AS ANOTHER FAST MOVING SHORT WAVE TROUGH SLIDES THROUGH
THE SOUTHERN PLAINS ON THE BACK OF A STRONG JET PARKED OVER THE
GULF SOUTH. ANOTHER GULF LOW SHOULD DEVELOP ALONG A STALLED OUT
FRONTAL BOUNDARY IN THE WESTERN GULF OF MEXICO. ONCE
AGAIN...MOISTURE WILL STREAM INTO THE REGION TUESDAY NIGHT...WITH
INCREASING CLOUDS EXPECTED INITIALLY. A FEW SHOWERS MAY BE ABLE TO
WORK DOWN TO THE SURFACE BY DAYBREAK OVER WESTERN ZONES...AS
MOISTURE BUILDS DOWN TO THE SURFACE FROM ALOFT. THE DRY AND STABLE
LAYER AT THE SURFACE WILL COMPLETELY ERODE BY WEDNESDAY
AFTERNOON...AS THE SURFACE LOW MOVES INTO SOUTHERN LOUISIANA. HAVE
WENT WITH CHANCE POPS FOR WEDNESDAY AND WEDNESDAY NIGHT...AS THE
LOW IMPACTS THE REGION. IT THEN APPEARS THAT ANOTHER MUCH STRONGER
UPPER LEVEL SYSTEM WILL SWEEP THROUGH THE REGION THURSDAY AND
THURSDAY NIGHT. HOWEVER...MOISTURE WILL BE MORE LIMITED FOR THIS
SYSTEM. HAVE KEPT IN A SLIGHT CHANCE FOR POPS...BUT UNCERTAINTY IS
HIGH CONCERNING THIS LATE WEEK SYSTEM.
AVIATION...
LINGERING SHOWERS AND MVFR CEILINGS WILL BE THE MAIN IMPACTS AT
THE TERMINALS THROUGH THE OVERNIGHT HOURS...AS A STRONG LOW
PRESSURE SYSTEM MOVES FROM THE ARKLATEX INTO THE MIDWEST. STRONG
SUBSIDENCE AND DRY AIR ADVECTION WILL FINALLY TAKE HOLD
TOMORROW...ALLOWING FOR RETURN TO VFR CONDITIONS. WINDS WILL ALSO
REMAIN QUITE STRONG FROM THE WEST AND NORTHWEST AT ALL TERMINALS
THROUGH TOMORROW AS A TIGHT PRESSURE GRADIENT BETWEEN THE LOW AND
A HIGH TO THE SOUTH AND EAST REMAINS IN PLACE. WINDS OF 15 TO 20
KNOTS WITH HIGHER GUSTS CAN BE EXPECTED.
MARINE...
STRONG GRADIENT FLOW WILL CONTINUE TO IMPACT THE COASTAL WATERS
AND TIDAL LAKES THROUGH TOMORROW. SMALL CRAFT ADVISORIES WILL
REMAIN POSTED FOR ALL COASTAL WATERS DUE TO STRONG GRADIENT FLOW.
IN FACT...GUSTS TO GALE FORCE WILL CONTINUE TO BE A
CONCERN...MAINLY EAST OF THE RIVER THROUGH THE LATE EVENING HOURS
TONIGHT. THE GRADIENT FLOW WILL FINALLY BEGIN TO WEAKEN TOMORROW
NIGHT...AS HIGH PRESSURE BECOMES CENTERED OVER THE GULF SOUTH.
HOWEVER...THIS HIGH WILL QUICKLY SHIFT TO THE EAST ON
SATURDAY...AS ANOTHER FAST MOVING GULF LOW DEVELOPS IN THE WESTERN
GULF OF MEXICO. THIS GULF LOW WILL PASS THROUGH THE COASTAL WATERS
SATURDAY NIGHT INTO SUNDAY. A BRIEF PERIOD OF ADVISORY WINDS AND
SEAS COULD DEVELOP AS THIS LOW PASSES THROUGH. IN THE WAKE OF THE
LOW...STRONG COLD AIR ADVECTION WILL ALLOW FOR AMPLE THERMAL
MIXING OVER THE WARMER WATERS...WHICH WILL KEEP WINDS ELEVATED
THROUGH MONDAY. WINDS WILL FINALLY DECREASE MONDAY NIGHT AND
TUESDAY...AS AN AREA OF HIGH PRESSURE SETTLES OVER THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 34 47 28 56 / 20 0 0 10
BTR 34 48 30 56 / 10 0 0 10
MSY 37 50 36 55 / 20 0 0 10
GPT 37 51 30 55 / 40 0 0 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...COASTAL FLOOD ADVISORY UNTIL 9 PM THURSDAY FOR THE FOLLOWING
ZONES: LOWER PLAQUEMINES...LOWER ST.
BERNARD...ORLEANS...ST. TAMMANY...AND UPPER ST. BERNARD.
SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 6 PM FRIDAY FOR THE
FOLLOWING ZONES: LOWER ST. BERNARD...AND LOWER TERREBONNE.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM FRIDAY FOR THE FOLLOWING ZONES:
AND LAKE PONTCHARTRAIN AND LAKE MAUREPAS.
SMALL CRAFT ADVISORY UNTIL 6 PM FRIDAY 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...COASTAL FLOOD ADVISORY UNTIL 9 PM THURSDAY FOR THE FOLLOWING
ZONES: HANCOCK...HARRISON...AND JACKSON.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM FRIDAY FOR THE FOLLOWING ZONES:
AND LAKE PONTCHARTRAIN AND LAKE MAUREPAS.
SMALL CRAFT ADVISORY UNTIL 6 PM FRIDAY 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.
&&
$$
