FXUS64 KLIX 252047
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
247 PM CST WED NOV 25 2009
.SYNOPSIS...
A SURFACE LOW IS LOCATED OVER NORTHERN MICHIGAN WITH A COLD FRONT
EXTENDING SOUTHWARD ALONG THE APPALACHIANS AND INTO THE CENTRAL
GULF OF MEXICO. SURFACE HIGH PRESSURE IS CENTERED OVER THE CENTRAL
PLAINS WITH A RIDGE AXIS EXTENDING INTO CENTRAL TEXAS. ANOTHER
SURFACE LOW IS CENTERED OVER NORTHWEST CANADA WITH A COLD FRONT
EXTENDING SOUTHWARD INTO THE PACIFIC OCEAN JUST OFF SHORE FROM
OREGON AND WASHINGTON.
LOCALLY...A BEAUTIFUL DAY IS WELL UNDERWAY WITH CLEAR SKIES AND
TEMPERATURES IN THE LOW TO MID 60S. DEWPOINTS IN THE 30S HAVE ALSO
RESULTED IN LOW RELATIVE HUMIDITY.
&&
.SHORT TERM...
A SECONDARY UPPER LEVEL TROUGH WILL DIG SOUTHWARD INTO THE LOWER
MISSISSIPPI VALLEY TONIGHT BRINGING A REINFORCING SURGE OF COOL
AND DRY AIR INTO THE AREA. DESPITE CLEAR SKIES...AFTERNOON
TEMPERATURES WILL BARELY NUDGE PAST THE 60 DEGREE MARK THURSDAY AS
STRONG COLD AIR ADVECTION TAKES HOLD OF THE AREA. ADDITIONALLY...
LOW DEWPOINTS WILL CONTINUE TO KEEP RELATIVE HUMIDITY VALUES IN
THE MID 30 PERCENT RANGE. ALL IN ALL...IT SHOULD BE A GORGEOUS
TURKEY DAY.
EXPECT THE COLDEST TEMPERATURES OF THE SEASON THUS FAR TO IMPACT
THE AREA THURSDAY NIGHT/FRIDAY MORNING AS THE SURFACE RIDGE
BECOMES CENTERED CLOSER TO THE REGION. AM FORECASTING A FEW HOURS
OF FREEZING TEMPERATURES ACROSS AREAS THAT ARE GENERALLY NORTH OF
THE INTERSTATE 10/12 CORRIDOR AND EAST OF INTERSTATE 55.
ELSEWHERE...A FEW HOURS OF NEAR FREEZING TEMPERATURES CAN BE
EXPECTED THROUGH THE BATON ROUGE AREA...WHILE AREAS SOUTH OF THE
INTERSTATE 10/12 CORRIDOR WILL REMAIN A BIT WARMER WITH
TEMPERATURES IN THE UPPER 30S AND LOW 40S.
THE HIGH WILL CONTINUE TO MOVE EASTWARD ON FRIDAY...WITH A BRIEF
PERIOD OF NEAR FREEZING TEMPERATURES POSSIBLE ALONG INTERIOR
PORTIONS OF THE MISSISSIPPI GULF COASTAL COUNTIES EARLY SATURDAY
MORNING.
.LONG TERM...
A WARMING TREND WILL BEGIN SATURDAY NIGHT AS THE HIGH CONTINUES TO
SHIFT EASTWARD AND A DEEP UPPER TROUGH DIGS INTO SOUTHWEST CONUS.
AS THIS HAPPENS...LOCAL WINDS WILL BECOME MORE EASTERLY AND THEN
SOUTHEASTERLY...WHICH WILL ALSO RESULT IN AN INFLUX OF MOISTURE
FROM THE GULF OF MEXICO. EXPECT TEMPERATURES TO MODERATE TO NEAR
NORMAL CONDITIONS OVER THE WEEKEND.
BEGINNING SUNDAY...THERE IS SIGNIFICANT SPREAD IN THE MODEL
SOLUTIONS CONCERNING THE EVOLUTION AND PROGRESSION OF THIS NEXT
SYSTEM. THE GFS HAS BEEN INCREDIBLY INCONSISTENT FROM RUN TO RUN.
WHILE IT HAD PREVIOUSLY CONTAINED THE STRONGEST AND FASTEST
SOLUTION...IT NOW DEVELOPS A CUTOFF LOW AT 500 MB WHICH
SIGNIFICANTLY SLOWS...AND TEMPORARILY STALLS...THE SURFACE COLD
FRONT AS IT APPROACHES THE LOCAL AREA. CONVERSELY...THE ECMWF HAS
BEEN A BIT MORE CONSISTENT MOVING THE SURFACE FRONT INTO THE
NORTHERN GULF SOME TIME MONDAY THEN STALLING IT THERE FOR A DAY OR
TWO BEFORE A SECONDARY SURGE FORCES IT WELL INTO THE GULF
WEDNESDAY NIGHT.
GIVEN THE MODEL SPREAD...HAVE GENERALLY GONE WITH A BLEND OF THE
TWO MODELS BUT HAVE GIVEN SLIGHTLY MORE WEIGHT TO THE ECMWF AS IT
HAS BEEN MORE CONSISTENT.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. A GUSTS OF 15 TO
20 KNOTS WILL BE POSSIBLE AT KMSY DURING THE LATE MORNING AND
AFTERNOON HOURS THURSDAY.
&&
.MARINE...
BREEZY CONDITIONS ARE EXPECTED TO RETURN TO THE GULF WATERS
OVERNIGHT TONIGHT AS A REINFORCING HIGH BEGINS TO MOVE INTO THE
AREA. EXERCISE CAUTION HEADLINES ARE IN EFFECT BEGINNING AT 9 PM
THIS EVENING. THE CAUTION HEADLINES WILL LIKELY NEED TO BE
REPLACED BY SMALL CRAFT ADVISORIES BY THURSDAY AFTERNOON AS STRONG
COLD AIR ADVECTION SHOULD HELP TRANSPORT SOME EVEN STRONGER WINDS
DOWN TO THE SURFACE. WINDS SHOULD QUICKLY RELAX FRIDAY MORNING AS
THE HIGH BECOMES CENTERED CLOSER TO THE AREA. AS THE HIGH
CONTINUES TO SHIFT EASTWARD...ONSHORE FLOW IS EXPECTED TO BEGIN
OVER THE WEEKEND. UNCERTAINTY REMAINS HIGH IN THE FAR EXTENDED
PERIOD AS THERE IS STILL CONSIDERABLE MODEL SPREAD CONCERNING THE
NEXT COLD FRONT...CURRENTLY FORECAST TO MOVE INTO THE COASTAL
WATERS MONDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 38 60 31 61 / 0 0 0 0
BTR 40 62 34 62 / 0 0 0 0
MSY 46 62 40 61 / 0 0 0 0
GPT 42 63 35 62 / 0 0 0 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
95/DM
