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536
FXUS64 KLIX 191420
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
920 AM CDT SUN MAY 19 2013

.UPDATE...

.SOUNDING DISCUSSION...

NO PROBLEMS WITH THE FLIGHT THIS MORNING. A VERY SUMMER-LIKE
MORNING WITH PLENTY OF INSTABILITY AND MOISTURE NEAR THE SURFACE
WITH A PW OF 1.37 INCHES AND AN LI OF -10.6. A SIGNIFICANT CAP
ONCE AGAIN TODAY AT AROUND AND ABOVE 900 MB...KEEPING AFTERNOON
AND EVENING CONVECTION TO A MINIMUM. A LIGHT SOUTHERLY FLOW IN THE
LOWER LEVELS WITH A MODERATE TO STRONG WEST...SOUTHWESTERLY FLOW
ALOFT.

&&

.PREV DISCUSSION... /ISSUED 457 AM CDT SUN MAY 19 2013/

SHORT TERM...

NOT MUCH CHANGE IN THE WEATHER PATTERN IS EXPECTED OVER THE NEXT
FEW DAYS...EXCEPT THE CAP AROUND 800 MB/7000 FEET MAY WEAKEN
SLIGHTLY THROUGH TUESDAY AS LOWER LEVEL HIGH PRESSURE UP TO ABOUT
600 MB SHIFTS EAST RESULTING IN DEEPER LAYER SOUTHERLY WINDS. AN
INCREASE IN MID TO UPPER LEVEL CLOUDS TODAY WILL LIKELY OFFSET ANY
WEAKENING OF THE CAP...SO IT IS EXPECTED TO REMAIN DRY. THERE MAY
BE JUST ENOUGH MOISTURE AND INSTABILITY FROM SLIGHTLY STRONGER
DAYTIME HEATING FOR SOME ISOLATED SHOWERS AND THUNDERSTORMS TO
DEVELOP DURING THE LATE MORNING AND AFTERNOON ON MONDAY ACROSS THE
ABOUT THE NORTHWEST HALF OF THE AREA WHERE THE CHANCE OF RAIN WILL
BE 10 TO 15 PERCENT. ON TUESDAY...A SHORTWAVE TROUGH IS EXPECTED
TO MOVE INTO THE SOUTHERN PLAINS WHICH WILL ERODE THE MID LEVEL
RIDGE NEAR THE CENTRAL GULF COAST. ONCE AGAIN...INSTABILITY MAY BE
SUFFICIENT TO OVERCOME ANY WEAK CAP...BUT THE MOISTURE MAY BE
LACKING...SO HAVE KEPT MENTION OF RAIN OUT OF MOST OF THE FORECAST
AREA. TEMPERATURES WILL REMAIN SEASONABLY WARM FOR DAYTIME HIGHS
WITH WARMER THAN AVERAGE LOWS DUE TO HIGH DEWPOINTS AND SOUTHERLY
WINDS OF 3 MPH OR HIGHER THROUGH MOST OF THE NIGHTTIME PERIODS.

LONG TERM...

THE SHORTWAVE TROUGH IS EXPECTED TO WEAKEN AND DEAMPLIFY AS IT
MOVES EAST-NORTHEAST ACROSS THE LOWER MISSISSIPPI VALLEY ON
WEDNESDAY...AND THE MODELS AGREE ON A WEAKER SOLUTION FROM SOME
RECENT EARLIER RUNS. ANY SUBSTANTIAL SURFACE BOUNDARIES WILL HAVE
TO COME FROM ANY THUNDERSTORM OUTFLOW BOUNDARIES OR A WEAK
SEABREEZE. HAVE MAINTAINED LOW END CHANCE CATEGORY RAIN CHANCES
OVER THE MORE INLAND AREAS WITH ONLY A SLIGHT CHANCE CLOSER TO THE
COAST.

MID/UPPER LEVEL TROUGHS ARE EXPECTED OVER/NEAR BOTH THE WEST AND
EAST COASTS BY LATE THURSDAY INTO THE FIRST PART OF THE WEEKEND
WITH A RIDGE EXPECTED TO BUILD OVER THE CENTRAL STATES AND
CENTRAL GULF COAST REGION. AT THIS TIME...IT DOES NOT APPEAR A
CAPPING INVERSION WILL REDEVELOP...AND STRONG DAYTIME HEATING
ALONG WITH MODEST PRECIPITABLE WATER VALUES SHOULD CONTINUE TO
SUPPORT ISOLATED SHOWERS AND THUNDERSTORMS THURSDAY THROUGH
SATURDAY. TEMPERATURES ARE EXPECTED TO REMAIN NEAR TO SLIGHTLY
HIGHER THAN SEASONAL AVERAGES. OVERALL...A MOSTLY DRY AND WARM
PATTERN IS EXPECTED THE NEXT 7 TO 10 DAYS. 22/TD

AVIATION...

AN ELEVATED INVERSION COMBINED WITH AMPLE LOW TO MID-LEVEL MOISTURE
HAS ALLOWED FOR THE FORMATION OF A SCATTERED TO BROKEN STRATUS DECK
TONIGHT.  CEILINGS ARE GENERALLY RANGING FROM 500 TO 1500 FEET AND
SHOULD REMAIN IN THE IFR/MVFR RANGE THROUGH AROUND 14-15Z THIS
MORNING.  AS THE INVERSION WEAKENS AFTER 15Z...AND DRIER AIR FROM
ALOFT MIXES DOWN...THE STRATUS DECK WILL BREAK UP AND LIFT TO AROUND
3000 TO 4000 FEET.  A SCATTERED STRATOCU FIELD SHOULD THEN REMAIN IN
PLACE THROUGH MUCH OF THE DAY...WITH SOME FURTHER CLEARING EXPECTED
BY 00Z.  UNFORTUNATELY...THE OVERALL ATMOSPHERE WILL BE LITTLE
CHANGED HEADING INTO TOMORROW NIGHT...AND ANOTHER ROUND OF LOW
STRATUS IS EXPECTED TO DEVELOP AROUND 06Z AND PERSIST INTO 12Z.
ONCE AGAIN...CEILINGS OF 500 TO 1000 FEET CAN BE EXPECTED. 32

MARINE...

LOW LEVEL RIDGING WILL REMAIN PARKED OVER THE SOUTHEAST AND EASTERN
GULF OF MEXICO...KEEPING A PERSISTENT SOUTHEAST FLOW OF 10 TO 15
KNOTS IN PLACE OVER THE COASTAL WATERS THROUGH TUESDAY.  SEAS WILL
GENERALLY RANGE FROM 2 TO 4 FEET...WITH THE HIGHEST SEAS AND
STRONGEST OVERALL GRADIENT FLOW OVER THE WESTERN WATERS.  ON
WEDNESDAY...THE RIDGE WILL BECOME MORE CENTERED OVER THE
AREA...RESULTING IN MUCH LIGHTER AND MORE VARIABLE WINDS FOR
WEDNESDAY AND THURSDAY.  SEAS WILL ALSO FALL TO AROUND 1 TO 2 FEET
DURING THIS PERIOD.  THE LOW LEVEL RIDGING WILL WEAKEN ON
FRIDAY...AS A FRONTAL BOUNDARY SLIDES THROUGH FROM THE NORTHEAST.
WINDS WILL SHIFT TO THE NORTHEAST BEHIND THIS FRONT...AND SHOULD
ALSO INCREASE IN SPEED TO AROUND 10 KNOTS.  EXPECT TO SEE SEAS CLIMB
BACK TO AROUND 2 TO 3 FEET DUE TO THE INCREASED GRADIENT FLOW.
WINDS WILL TURN EASTERLY OVER THE WEEKEND...AS A NEW LOW LEVEL RIDGE
SETS UP OVER THE DEEP SOUTH STATES. 32

DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
             MONITORING RIVER FLOODING.

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  87  70  88  68 /   0   0  10  10
BTR  87  71  89  71 /   0   0  10  10
ASD  85  71  87  69 /   0   0  10  10
MSY  85  72  87  71 /   0   0  10  10
GPT  82  73  84  69 /   0   0  10  10
PQL  84  69  85  68 /   0   0  10  10

&&

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

$$