National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

447
FXUS64 KLIX 160836
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
336 AM CDT THU MAY 16 2013

.SHORT TERM...

A VIGOROUS UPPER LEVEL LOW CURRENTLY MOVING THROUGH THE SOUTHERN
PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY WILL BE THE MAIN
FEATURE IMPACTING THE FORECAST THROUGH SATURDAY. FORTUNATELY...THE
STRONG DYNAMIC AND THERMODYNAMIC SUPPORT FOR STRONG TO SEVERE
THUNDERSTORM ACTIVITY WILL REMAIN WELL NORTH OF THE REGION. ACROSS
THE FORECAST AREA...SOME MARINE LAYER ACTIVITY CURRENTLY MOVING
OVER THE REGION WILL SHIFT TO THE EAST DURING THE MORNING HOURS.
SOME LIGHT SHOWER ACTIVITY COULD PERSIST OVER EXTREME SOUTHEAST
LOUISIANA AND COASTAL MISSISSIPPI THROUGH THE EARLY MORNING HOURS.

HEADING INTO THE AFTERNOON HOURS...SOME MID TO UPPER LEVEL ENERGY
TIED INTO A WEAKENING MESOSCALE CONVECTIVE COMPLEX CURRENTLY OVER
NORTHERN TEXAS WILL SLIDE THROUGH THE REGION. THIS FORCING
ALOFT...COMBINED WITH AMPLE DAYTIME HEATING SHOULD BE ENOUGH TO
SPARK OFF SOME ISOLATED CONVECTION. FORTUNATELY...LAPSE RATES
ALOFT WILL BE FAIRLY WEAK AND OVERALL CAPE VALUES WILL REMAIN
BELOW 1000 J/KG. THIS WILL GREATLY INHIBIT THE FORMATION OF
SUSTAINED DEEP UPDRAFTS AND DO NOT EXPECT ANY STRONG TO SEVERE
THUNDERSTORM ACTIVITY IN THE FORECAST AREA TODAY. IN ADDITION...THERE
WILL BE NO SIGNIFICANT LOW LEVEL BOUNDARIES IN THE AREA...OUTSIDE OF
SEABREEZE/LAKEBREEZE BOUNDARIES. EXPECT ANY CONVECTION TO
INITIALLY DEVELOP IN RELATION TO THESE MESOSCALE BOUNDARIES.
ADDITIONAL CONVECTION WILL THEN FEED OFF OF THE OUTFLOW OF THE
PREVIOUS STORMS.

THE CONVECTION WILL QUICKLY DIE OFF AFTER SUNSET...AS DAYTIME
HEATING WANES AND AN ELEVATED INVERSION DEVELOPS. HEADING INTO
FRIDAY AFTERNOON...ANOTHER ROUND OF DIURNALLY INDUCED CONVECTION
IS EXPECTED. THE SITUATION WILL BE PRACTICALLY THE SAME AS THAT ON
THURSDAY WITH ONLY ISOLATED CONVECTION FIRING ALONG LOCALIZED
BOUNDARIES EXPECTED.

HEADING INTO SATURDAY...STRONG UPPER LEVEL RIDGING WILL BEGIN TO
BUILD OVER THE AREA AS THE UPPER LEVEL LOW SHIFTS TO THE EAST.
THIS STRONG RIDGING ALOFT AND THE RESULTANT SUBSIDENCE WILL
EFFECTIVELY PUT A CAP ON ANY CONVECTIVE POTENTIAL. EXPECT TO SEE
MOSTLY CLEAR SKIES AND WARMER TEMPERATURES FOR SATURDAY. HIGHS
WILL EASILY CLIMB INTO THE UPPER 80S ACROSS THE REGION.

.LONG TERM...

THE UPPER LEVEL RIDGE WILL REMAIN PARKED OVER THE AREA THROUGH
TUESDAY. A VERY SUMMER LIKE PATTERN WILL BE IN PLACE WITH DAYTIME
HIGHS CLIMBING INTO THE UPPER 80S AND LOWER 90S AND OVERNIGHT LOWS
ONLY COOLING TO NEAR 70 DEGREES. STRONG SUBSIDENCE ALOFT WILL KEEP
CONVECTIVE POTENTIAL AT A MINIMUM EACH DAY. BY WEDNESDAY...THE
RIDGE WILL BREAK DOWN SLIGHTLY AS A FAST MOVING SHORT-WAVE TROUGH
SLIDES THROUGH THE MID-MISSISSIPPI VALLEY. HOWEVER...THIS FEATURE
WILL HAVE VERY LITTLE IMPACT ON THE REGION WITH CONTINUED WARM AND
DRY WEATHER EXPECTED. RIDGING WILL ONCE AGAIN REBUILD BACK OVER
THE GULF SOUTH ON THURSDAY...KEEPING THE SUMMER LIKE CONDITIONS IN
PLACE.

&&

.AVIATION...
GENERAL VFR CONDITIONS TO IS EXPECTED FOR THE MOST PART. WEAK LOW
LEVEL CONVERGENT FEATURES DEVELOPING MARINE LAYER LIGHT SHOWERS FROM
BASES SCT-BKN 015-020 THIS MORNING...BUT QUITE TRANSIENT IN
COVERAGE. RATHER STRONG UPPER LEVEL DISTURBANCE OVER NORTH TEXAS WITH
ASSOCIATED MCS STRUCTURE HAD TOPS WARMING RECENTLY INDICATING
DISSIPATION...THOUGH DAYTIME HEATING IS LIKELY TO COINCIDE WITH GULF
BREEZE CONVERGENCE TO AID IN DEVELOPING SCATTERED CONVECTION THIS
AFTERNOON AS UPPER DISTURBANCE SWEEPS TO THE NORTHEAST DURING THE
DAY. AT THIS TIME...PUBLIC 20 PERCENT WILL NOT WARRANT MENTION IN
TAFS BUT COULD PROMPT SHORT-TERM AMENDMENTS AT SELECT TERMINALS
SHOULD RADAR TRENDS SUPPORT A LOCALIZED THREAT. 24/RR

&&

.MARINE...
STEADY STATE ONSHORE WIND PATTERN UNDERWAY AND TO PERSIST FOR THE
NEXT 5 TO 7 DAYS WITH LITTLE CHANGE. SEAS EXPECTED TO ALSO REMAIN AT
RELATIVELY LOW LEVELS WITH A GRADUAL GROUND SWELL BUILDUP FROM THE
SOUTHEAST DUE TO PERSISTENT FETCH FROM THE FLORIDA STRAITS AND
YUCATAN CHANNEL REGION. UPPER LEVEL DISTURBANCE GRAZING THE GULF
STATES TODAY MAY IMPART ISOLATED SHOWERS AND THUNDERSTORMS IN THE
COASTAL WATERS. 24/RR

&&

.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  84  66  85  67 /  20  10  20  10
BTR  85  68  86  69 /  20  10  20  10
ASD  83  67  83  67 /  20  10  20  10
MSY  83  69  84  70 /  20  10  20  10
GPT  81  69  82  69 /  20  10  20  10
PQL  81  66  82  67 /  10  10  20  10

&&

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

$$

32