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FXUS64 KLIX 062033
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
333 PM CDT MON OCT 6 2008

.SHORT TERM...

A STRONG SLIGHTLY NEGATIVELY TILTED SHORT WAVE TROUGH WILL
CONTINUE TO ADVANCE THROUGH THE PLAINS AND INTO THE MIDWEST AND
TENNESSEE VALLEY TONIGHT INTO TOMORROW. AS THE TROUGH PULL
EASTWARD...A DEVELOPING AREA OF LOW PRESSURE AND ASSOCIATED COLD
FRONT DIVE THROUGH THE SOUTHERN PLAINS TOWARD THE LOWER
MISSISSIPPI VALLEY. ALL OF THE MODELS ARE IN GOOD AGREEMENT ON THE
EVOLUTION OF THE SYSTEM...BUT THERE ARE TIMING DIFFERENCES ON THE
FRONTAL PASSAGE TUESDAY NIGHT INTO WEDNESDAY. THE GFS IS MOST
AGGRESSIVE WITH THE FRONT...WHILE THE ECMWF AND NAM ARE A BIT
SLOWER AND KEEP LINGERING MOISTURE ACROSS THE AREA THROUGH
WEDNESDAY. HAVE DECIDED TO GO WITH A BLEND OF THE MODELS...WITH A
BIT MORE EMPHASIS ON THE GFS SOLUTION.

WITH THIS IN MIND...EXPECT WEAK INVERTED TROUGH IN THE NORTH
CENTRAL GULF TO CONTINUE TO PULL MOISTURE INTO THE REGION TONIGHT.
SCATTERED SHOWERS CURRENTLY MOVING ONSHORE SHOULD OVERSPREAD THE
FORECAST AREA OVERNIGHT...AND HAVE BUMPED UP POPS TO HIGH END
CHANCE TO REFLECT THIS. DEEP MOISTURE COMBINED WITH A MARGINALLY
UNSTABLE ATMOSPHERE AND A BROAD AREA OF LIFT THROUGHOUT THE
ATMOSPHERIC COLUMN WILL SUPPORT LIKELY POPS TOMORROW IN ADVANCE OF
THE APPROACHING TROUGH AXIS AND FRONTAL BOUNDARY.

GOING INTO TUESDAY NIGHT...EXPECT THE FRONTAL BOUNDARY TO PASS
THROUGH THE FORECAST AREA. MODEL SOUNDINGS INDICATE A MARGINALLY
UNSTABLE ATMOSPHERE WILL BE IN PLACE AS THE FRONT PULLS THROUGH.
HOWEVER...THE POSSIBILITY DOES EXIST FOR A SQUALL OR SOME BOWING
SEGMENTS TO DEVELOP AS A STRONG SPEED SHEAR FROM 0 TO 3 KM OF
AROUND 20 KNOTS WILL BE PLACE. KEEP POPS UP INTO THE LIKELY
CATAGORY FOR EASTERN AND SOUTHERN ZONES...WITH HIGH END CHANCE
POPS ELSEWHERE. ON WEDNESDAY...EXPECT SOME LINGERING CLOUDS AND A
FEW SHOWERS ON THE BACK SIDE OF THE UPPER LEVEL LOW AS IT SLIDES
THROUGH THE SOUTHEASTERN STATES. STRONG SUBSIDENCE AND DRY AIR
ADVECTION WILL TAKE HOLD BY WEDNESDAY NIGHT ALLOWING FOR CLEARING
SKIES AND LOWER DEWPOINTS. SOME WEAK COLD AIR ADVECTION SHOULD
ALSO ACCOMPANY THE HIGH BUILDING INTO THE REGION...ALLOWING
TEMPERATURES TO FALL SLIGHTLY BELOW NORMAL.

.LONG TERM...

THE LATTER PART OF THE WEEK AND INTO THE WEEKEND...AN UPPER LEVEL
RIDGE AND ASSOCIATED SURFACE RIDGING WILL BE THE DOMINANT FEATURES
ACROSS THE CWA. THIS STRONG RIDGING WILL ALLOW FOR DRY CONDITIONS
AND A LARGE DIURNAL TEMPERATURE RANGE THURSDAY THROUGH SATURDAY.
HOWEVER...THE RIDGE WILL BEGIN TO PULL EASTWARD BY SATURDAY...AS A
STRONG UPPER LEVEL TROUGH DIGS INTO THE WESTERN HALF OF THE
NATION. SOUTHERLY FLOW WILL REDEVELOP ACROSS THE AREA FRIDAY NIGHT
INTO SATURDAY...ALLOWING FOR GULF MOISTURE TO SLOWLY MOVE BACK
OVER THE REGION. ENOUGH UPPER LEVEL SHOULD BE IN PLACE...AS A WEAK
SHORT WAVE MOVES THROUGH THIS WEEKEND TO SPARK OFF SOME SHOWERS
OVER WESTERN ZONES...AS THE MOISTURE WILL BE DEEPER IN THIS
REGION. BY MONDAY...DEEPER GULF MOISTURE SHOULD OVERSPREAD THE
REGION...ALLOWING FOR A SLIGHT CHANCE OF SHOWERS ACROSS THE CWA.
THESE SHOWERS WILL BE SPARKED BY A DIFLUENT FLOW ALOFT...AND THUS
A BROAD AREA OF ASCENT. TEMPERATURES WILL ALSO REBOUND THIS
WEEKEND AS THE GULF MOISTURE SPREADS IN...WITH LOWS CLIMBING BACK
INTO THE UPPER 60S AND LOWER 70S...AND HIGHS RISING INTO THE
MIDDLE TO UPPER 80S.

&&

.AVIATION...
MOST WEATHER ISSUES AT TERMINAL LOCATIONS WILL INVOLVE LOWERING OF
CEILINGS FROM LOW END VFR TO MVFR LATER TONIGHT AND IFR AROUND 12Z
TUESDAY. WILL SHOW PREVAILING SHRA COVERAGE ALL TERMINALS AFTER 12Z
BUT THERE MAY BE BREAKS AT TIMES...BUT DIFFICULT TO GAGE TIMING AND
AREAL EXTENT...SO WILL INDICATE FOR ENTIRE PERIOD 12Z THRU 18Z...AND
MAY NEED TO BE EXTENDED NEXT TAF PACKAGE BEYOND 18Z. MAY HAVE TO
CONSIDER AMENDMENTS FOR KGPT TO ADDRESS TSRA APPROACHING COAST FROM
NEARBY WATERS BUT THESE STORMS HAVE BEEN LINGERING OUT THERE ALL
MORNING AND EARLY AFTERNOON...WEAKENING AND DISSIPATING FARTHER
NORTH. AS COLUMN MOISTURE DEEPENS...CONVECTION WILL HAVE BETTER
CHANCES TO MAINTAIN OVER LAND. FRONTAL PASSAGE NOW APPEARS TO BE
EARLY WEDNESDAY MORNING WITH IMPROVING CONDITIONS THROUGHOUT THE
MORNING WEDNESDAY. 24

&&

.MARINE...
PERSISTENT EASTERLY WINDS INTO THE EAST FACING SHORES HAVE BROUGHT
AN INCREASE IN TIDE LEVELS ABOUT 1 TO 1.5 FEET ABOVE
NORMAL...INCLUDING THE TIDAL LAKES. WILL NOT ISSUE ANY STANDALONE
PRODUCT TO ADDRESS THIS SINCE IS SHOULD BE CONFINED TO HIGH TIDE AND
BECOME MITIGATED BY FRONTAL PASSAGE LATE TOMORROW NIGHT/EARLY
WEDNESDAY MORNING. WILL MENTION IN COASTAL WATERS FORECAST.
OTHERWISE...EAST TO SOUTHEAST WINDS AROUND 15 KNOTS AND SEAS 4 TO 6
FEET PRIOR TO FRONTAL PASSAGE AND WIND SHIFTING TO OFFSHORE
COMPONENT WEDNEDAY MORNING. 24

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  68  83  64  82 /  50  70  50  20
BTR  71  85  64  82 /  50  70  50  20
MSY  73  85  68  83 /  50  70  60  20
GPT  70  82  68  81 /  50  70  60  30

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&

$$

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