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573
FXUS64 KLIX 021311
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
811 AM CDT WED OCT 2 2013

.UPDATE...
...SOUNDING DISCUSSION...

NO PROBLEMS WITH THE FLIGHT THIS MORNING. THE BALLOON WAS LAUNCHED
THIS MORNING INTO A VERY LIGHT RAIN AND THE SOUNDING SHOWS A
NEARLY SATURATED ATMOSPHERE THROUGHOUT. PW VALUES ARE JUST OVER 2
INCHES WITH A LARGE RAIN SHIELD OVER THE SOUTHWESTERN PORTION OF
THE CWA AND MORE SCATTERED SHOWERS AND THUNDERSTORMS THROUGHOUT
THE REST OF THE AREA. THUNDERSTORM COVERAGE WILL LIKELY INCREASE
THIS AFTERNOON WITH THE MAIN THREAT BEING LOCALLY HEAVY RAINFALL
WITH THE AFOREMENTIONED COPIOUS AMOUNT OF MOISTURE AVAILABLE. SOME
OF THE THUNDERSTORMS COULD ALSO PRODUCE WIND GUSTS IN THE RANGE OF
20-30 MPH BUT WILL MORE THAN LIKELY REMAIN WELL BELOW SEVERE
LIMITS. WINDS ARE CALM AT THE SURFACE AND ARE OUT OF THE SOUTHWEST
ALOFT.

98/SO

&&

.PREV DISCUSSION... /ISSUED 413 AM CDT WED OCT 2 2013/

SHORT TERM...
LATEST IR IMAGERY SHOWS THE UPPER LOW MOVING NORTHWARD INTO THE
MISSISSIPPI DELTA. SOME DEEPER CONVECTION HAS DEVELOPED ALONG THE
LOUISIANA COAST AND IS SLOWLY MOVING NORTH INTO TERREBONNE PARISH
THIS MORNING. A FEW LIGHTNING STRIKES HAVE BEEN OBSERVED IN THIS
CONVECTION AND WITH THE ATMOSPHERE STILL HOLDING UP TO 2 INCHES OF
PRECIPITABLE WATER...HEAVY RAINFALL IS ALSO ONGOING. MORE OF THESE
TYPES OF SHOWERS AND STORMS WILL MOVE INTO THE FORECAST AREA THIS
MORNING AND LAST THROUGHOUT THE DAY. WILL CARRY 50 PERCENT CHANCE
OF SHOWERS AND THUNDERSTORMS TODAY. 13/MH

LONG TERM...
THE BIGGEST CHALLENGE IN THE FORECAST COMES IN THE LONG RANGE
PERIOD AS SEVERAL FACTORS PLAY AN IMPORTANT ROLE IN THE FORECAST
FOR THIS WEEKEND.A TROUGH IS EXPECTED TO DIP SOUTHEAST ACROSS THE
PACIFIC NORTHWEST TOWARDS THE ROCKY MOUNTAINS LATER THIS WEEK.
SATURDAY INTO SUNDAY THIS FEATURE WILL BE AMPLIFYING AS IT TRACKS
ACROSS THE MID SECTION OF THE COUNTRY. A COLD FRONT WILL BE
MARCHING SOUTH AHEAD OF THE TROUGH TOWARDS THE CWA THIS WEEKEND.
AT THE SAME TIME MODELS DEPICT A TROPICAL LOW MOVING INTO THE
NORTHERN GULF OF MEXICO. MODELS ARE HAVING A HARD TIME RESOLVING
THIS FEATURE AND PROBABLY WILL CONTINUE TO HAVE TROUBLE WITH IT
UNTIL IT GETS MORE DEVELOPED. THE HURRICANE CENTER HIGHLIGHTS THIS
AREA AND HAS THIS DISTURBANCE AT A 50 PERCENT CHANCE OF BECOMING A
TROPICAL CYCLONE OVER THE NEXT 3 TO 5 DAYS.

TAKING A PEEP AT THE MODELS AGAIN TODAY IT LOOKS LIKE THE ECMWF
CONTINUES TO BE SLOWER WITH THE PROGRESSION OF THE FRONT AND WOULD
ALLOW THE TROPICAL FEATURE TO GET FURTHER WEST AND MUCH CLOSER TO
THE FORECAST AREA. THE GFS ON THE OTHER HAND IS MORE PROGRESSIVE
WITH THE FRONT BY ABOUT 12 HOURS AND KEEPS THE TROPICAL FEATURE TO
THE EAST OF THE FORECAST AREA KEEPING THE BULK OF THE
PRECIPITATION TO THE EAST OF THE AREA. HAVE GENERALLY KEPT THE
SAME FORECAST FROM PREVIOUS FORECASTS BUT HAVE BUMPED UP POPS SOME
THIS WEEKEND. AFTER THE FRONT FALL WILL MAKE AN APPEARANCE AND YOU
WILL DEFINITELY FEEL THE DIFFERENCE IN THE OVERNIGHT LOWS AS THY
WILL DIP INTO THE 50S EARLY NEXT WEEK AND DAYTIME HIGHS WILL BE IN
THE LOW 80S. HIGH PRESSURE BUILDS IN BEHIND THE FRONT YIELDING FOR
SOME CLEAR DAYS. 13/MH

AVIATION...
UPPER LEVEL LOW INDICATED PROMINENTLY OVER THE MISSISSIPPI DELTA
REGION WITH TRAILING TROUGH TO THE GULF COAST. LARGE AREA OF
CONVECTION ALONG THE COAST IS LIKELY TO MOVE INLAND THIS MORNING AN
IMPACT KHUM...KMSY AND KNEW PROBABLY BY 15Z. LARGE SCALE INSTABILITY
AND LIFT UNDER CIRCULATION OF UPPER LOW SHOULD PRESENT A CHAOTIC
SITUATION AT TERMINALS IN REGARDS TO VARIABLE CEILINGS AND VSBY
ALONG WITH ON AND OFF CONVECTION THROUGH 00Z. WHILE MOST OF VALID
TIME PERIOD WILL BE VFR...SOME PERIODS OF MVFR TO BRIEF IFR
CONDITIONS WILL BE LIKELY WITH CONVECTION. 24/RR

MARINE...
A RELATIVELY FLAT WIND FIELD TODAY WILL GRADUALLY TIGHTEN TO
MODERATE LEVELS THURSDAY AND FRIDAY. GFS MODEL SHOWING DISTURBANCE
IN WESTERN CARIBBEAN SEA ACTUALLY BECOMING A WEAK TROPICAL CYCLONE
BY FRIDAY WHILE APPROACHING THE MOUTH OF THE MISSISSIPPI RIVER
BEFORE DEFLECTING TOWARDS THE WESTERN FLORIDA PANHANDLE. THE 00Z
ECMWF MODEL SHOWED A FARTHER WEST SOLUTION ALBEIT WEAKER. MODELS ARE
ALSO SUGGESTING A SLOWER FRONTAL PROGRESSION INTO SUNDAY...WHICH
WOULD HAVE SOME RAMIFICATIONS ON ANY LOW PRESSURE DEVELOPMENT IN THE
GULF. AT THIS TIME...WENT CLOSER TO GFS FOR CYCLONE TRACKING BUT
LOWERED WINDS TO 30 KT OR LESS THROUGH SATURDAY AS COLLABORATED WITH
MOBILE AND TAFB UNIT. SEAS EXPECTED TO BUILD INTO THE 7-10 FT RANGE
IF THE LOW DOES MATERIALIZE BY THURSDAY EVENING...THEN LOWER TO THE
4-6 FT RANGE LATE SATURDAY AS FRONT MOVES THROUGH THE COASTAL
WATERS. SMALL CRAFT ADVISORIES WILL BE NEEDED THURSDAY IN THE EVENT
A LOW PRESSURE SYSTEM DOES DEVELOP...BUT MAY TRANSITION TO TROPICAL
BASED PRODUCTS IF NHC INITIATES A NAMED SYSTEM WITH THIS FEATURE.
24/RR

DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT

DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN  = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE   = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
         VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
         WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
         TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED    = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
         AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
         SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  85  68  87  69 /  60  10  20  10
BTR  86  70  88  70 /  60  10  30  20
ASD  86  70  88  72 /  50  10  20  20
MSY  86  74  88  75 /  60  10  30  20
GPT  85  72  87  73 /  50  20  30  20
PQL  86  71  87  72 /  40  10  30  30

&&

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

$$