229 FXUS64 KLIX 112057 AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 357 PM CDT SUN MAY 11 2014 .SHORT TERM... SCATTERED CONVECTION THAT DEVELOPED ALONG A REMNANT TROUGH AXIS TODAY WILL DISSIPATE DURING THE EVENING HOURS...AS DIURNAL HEATING WANES. EXPECT TO SEE NO PRECIPITATION OVER THE AREA BY LATE THIS EVENING AS THE AIRMASS STABILIZES. AFTER MIDNIGHT...AN ELEVATED INVERSION MAY TURNED SURFACE BASED OVER NORTHERN ZONES...RESULTING IN SOME PATCHY DENSE FOG. A REPEAT OF THE WEATHER OBSERVED TODAY WILL LIKELY HAPPEN TOMORROW AS THE LINGERING REMNANT TROUGH REMAINS OVER THE AREA. ONCE AGAIN...ISOLATED SHOWERS WILL DEVELOP ALONG THE LOUISIANA COAST AND THEN SPREAD INLAND ON THE BACK OF DEEP LAYER SOUTHERLY FLOW. DAYTIME HIGHS WARMING INTO THE MIDDLE 80S WILL ALSO HELP TO INCREASE OVERALL INSTABILITY BY PUSHING CAPE VALUES TO AROUND 1500-2000 J/KG. EXPECT TO SEE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS FORM OVER AREAS MAINLY ALONG AND NORTH OF THE INTERSTATE 10 CORRIDOR IN SOUTHEAST LOUISIANA AND SOUTHWEST MISSISSIPPI FROM LATE MORNING THROUGH THE AFTERNOON WHERE CAPE VALUES ARE HIGHEST AND HAVE GONE WITH LIKELY POPS FOR THE NORTHSHORE...BATON ROUGE...AND SOUTHWEST MISSISSIPPI ZONES. IN THE NEW ORLEANS AREA...EXPECT TO SEE ONLY SCATTERED CONVECTION DUE TO SLIGHTLY LOWER CAPE VALUES OF 1000-1500 J/KG AND HAVE GONE WITH CHANCE POPS FOR THE DAY. FURTHER TO THE EAST...THE SEABREEZE ALONG THE MISSISSIPPI COAST SHOULD KEEP MOST CONVECTION WELL NORTH OF THE AREA...AND ONLY HAVE SLIGHT CHANCE POPS IN PLACE FOR THE DAY. ON TUESDAY...THERE WILL BE A BIT MORE CONVECTIVE INHIBITION IN PLACE AS SOME DRIER MID-LEVEL AIR WORKS INTO THE REGION. A WEAK MID-LEVEL CAP WILL BE IN PLACE THROUGH THE MORNING HOURS...WHICH WILL KEEP A LID ON ANY CONVECTIVE DEVELOPMENT UNTIL THE ATMOSPHERE REACHES THE CONVECTIVE TEMPERATURE DURING THE AFTERNOON HOURS. OVERALL CAPE VALUES WILL ALSO BE DEPRESSED DUE TO THIS CAPPING ALOFT...WITH CAPE VALUES ONLY RANGING AROUND 1000 J/KG ON TUESDAY. GIVEN THE LOWER OVERALL INSTABILITY IN PLACE...EXPECT TO ONLY SEE ISOLATED CONVECTION DEVELOP OVER THE AREA AND HAVE PUT IN SLIGHT CHANCE POPS FOR THE DAY. CONDITIONS WILL BEGIN TO TURN MORE UNSTABLE AND OVERALL FORCING WILL IMPROVE OVER THE AREA LATE TUESDAY NIGHT AND WEDNESDAY...AS A BROAD REGION OF INCREASING POSITIVE VORTICITY ADVECTION AND RESULTANT INCREASED OMEGA OVERSPREAD THE AREA. EXPECT TO SEE PW VALUES INCREASE THROUGH THE NIGHT AS AN APPROACHING UPPER LEVEL TROUGH BRINGS SOME MID AND UPPER LEVEL MOISTURE BACK INTO THE AREA. OVERALL...ISOLATED TO SCATTERED SHOWERS SHOULD BEGIN TO MOVE INTO THE AREA LATE TUESDAY NIGHT...WITH THE HIGHEST RAIN CHANCES OVER NORTHERN AND WESTERN ZONES WHERE FORCING IS GREATEST. THE PARENT TROUGH AXIS WILL BEGIN TO TAKE ON A NEUTRAL TILT DURING THE DAY ON WEDNESDAY OVER THE ARKLATEX. AS THIS OCCURS...IT WILL DRIVE A COLD FRONT THROUGH THE FORECAST AREA. THIS FRONT WILL SERVE AS THE FOCUS FOR MORE ROBUST CONVECTIVE DEVELOPMENT OVER THE NORTHERN THIRD OF THE AREA ON SATURDAY. HAVE BUMPED UP POPS TO LIKELY FOR SOUTHWEST MISSISSIPPI...WITH CHANCE POPS ELSEWHERE. SHEAR PROFILES AND LAPSE RATES ARE FAIRLY WEAK...SO THE THREAT OF SEVERE WEATHER IS LOW. HOWEVER...A COUPLE OF STRONGER STORMS CANNOT BE RULED OUT OVER FAR NORTHERN ZONES. THE FRONT SHOULD PUSH OUT OF THE AREA DURING THE OVERNIGHT HOURS ON WEDNESDAY...WITH STRONG COLD AND DRY AIR ADVECTION TAKING HOLD WEDNESDAY NIGHT. .LONG TERM... HEADING INTO THE LATTER HALF OF THE WEEK...NORTHWEST FLOW WILL DOMINATE IN THE UPPER LEVELS...WITH A STRONG RIDGE BUILDING OVER THE AREA IN THE LOW TO MID-LEVELS. STRONG SUBSIDENCE THROUGHOUT THE ATMOSPHERIC COLUMN WILL KEEP SKIES MOSTLY CLEAR AND CONTINUED COLD AIR ADVECTION ASSOCIATED WITH THE DEEP TROUGH OVER THE EASTERN THIRD OF THE NATION WILL KEEP TEMPERATURES A GOOD 10 TO 15 DEGREES BELOW NORMAL. IN FACT...OVERNIGHT LOWS WILL LIKELY FALL INTO THE UPPER 40S OVER INLAND AREAS THURSDAY NIGHT. THE OVERALL AIRMASS WILL GRADUALLY MODIFY...AND READINGS SHOULD RETURN TO MORE NORMAL LEVELS BY THE WEEKEND. && .AVIATION... MUCH OF THE CONVECTION SHOULD HAVE ENDED BY 00Z AT THE TAF LOCATIONS THOUGH SOME -RA FROM DISSIPATING ANVILS MAY LINGER BEFORE 01Z. VFR CONDITIONS THROUGH ABOUT 08-09Z BEFORE MARINE LAYER CLOUDS SETTLE AT MVFR AND UPPER END IFR LEVELS PRIOR TO SUNRISE. CIGS IMPROVE TO VFR LEVELS WITH MIXING AROUND 15Z WITH SCATTERED TO BRIEFLY NUMEROUS TSRA DEVELOPING ONCE AGAIN BETWEEN 18Z-22Z MOST LOCATIONS. EXCEPTION MAY BE KGPT WHERE GULF BREEZE SHADOW MAY KEEP TSRA FARTHER NORTH OF THAT TERMINAL. 24/RR && .MARINE... A PERSISTENT SOUTHEAST WIND OF 15 TO 20 KNOTS AND SEAS OF 3 TO 6 FEET WILL KEEP ROUGH BOATING CONDITIONS IN PLACE OVER THE GULF COASTAL WATERS THROUGH MONDAY. GIVEN THESE CONDITIONS...HAVE RAISED EXERCISE CAUTION FLAGS OVER THE REGION. THERE WILL BE A BRIEF LULL IN THE STRONG SOUTHEAST FLOW ON TUESDAY AND WEDNESDAY...AS A COLD FRONT APPROACHES FROM THE WEST AND THE OVERALL GRADIENT OVER THE REGION WEAKENS. THIS WILL ALLOW SEAS TO FALL TO AROUND 3 TO 4 FEET OFFSHORE. HOWEVER...THIS LULL WILL BE SHORT-LIVED...AS THE COLD FRONT MOVES THROUGH THE COASTAL WATERS WEDNESDAY NIGHT. IN THE WAKE OF THE PASSING FRONT...STRONG COLD AIR ADVECTION OVER THE WARMER WATERS WILL ALLOW BOUNDARY LAYER WINDS OF 20 TO 25 KNOTS TO DROP DOWN TO THE SURFACE WATERS. EXPECT TO SEE A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS FORM LATE WEDNESDAY NIGHT AND PERSIST INTO THURSDAY. 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 68 85 67 85 / 20 60 20 20 BTR 72 87 69 86 / 20 60 20 20 ASD 72 83 70 84 / 10 50 20 20 MSY 73 83 71 83 / 10 50 20 20 GPT 73 82 72 83 / 10 30 10 20 PQL 69 82 68 82 / 10 30 10 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$ 32