972 
FXUS64 KLIX 130119
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
819 PM CDT SUN OCT 12 2014

.00Z SOUNDING DISCUSSION...

ROUTINE FLIGHT TERMINATED OVER EASTERN HANCOCK COUNTY MISSISSIPPI
JUST SOUTH OF THE LITTLE BILOXI WILDLIFE REFUGE SOUTHWEST OF
SAUCIER. FLIGHT TERMINATED AT AN ALTITUDE OF 111K FEET OR 21
MILES. 

AIRMASS HAS CONTINUED TO MOISTEN WITH A PRECIPITABLE WATER VALUE
OF 1.94 INCHES. THIS IS ABOUT 167 PERCENT OF NORMAL FOR OCTOBER.
LIFTED INDEX OF -5 AND CAPE AROUND 2000 J/KG. MID-LEVEL LAPSE
RATES AROUND 6C/KM. FREEZING LEVEL AT 14.7K FEET AND -20C AT 25.2K
FEET. 

SOUTHEAST WINDS AT THE SURFACE BECOME SOUTHWEST BY ABOUT 700 MB
AND REMAINED SOUTHWEST TO WEST THROUGH 100 MB. MAX WIND WAS
WESTERLY AT 65 KNOTS NEAR 200 MB. 35

&&

.PREV DISCUSSION... /ISSUED 337 PM CDT SUN OCT 12 2014/ 

DISCUSSION...
THE MAIN FORECAST CONCERN IS THE POTENTIAL FOR SEVERE WEATHER
MONDAY AFTERNOON AND MONDAY NIGHT. THE UPPER AIR PATTERN ACROSS
THE CONUS WILL AMPLIFY SIGNIFICANTLY EARLY IN THE FORECAST PERIOD
AS AN UPPER TROUGH MOVING OUT OF THE NORTHERN AND CENTRAL ROCKIES
AND INTO THE PLAINS LATE TODAY AND TONIGHT DEEPENS AND TAKES ON
MORE A NEUTRAL TILT AS IT MOVES ACROSS THE SOUTHERN PLAINS MONDAY
AND THE LOWER AND MID MISSISSIPPI VALLEY MONDAY NIGHT. THE MAIN
THREAT FOR SEVERE WEATHER FOR THE LOCAL FORECAST AREA WILL OCCUR
FROM MID AND LATE AFTERNOON MONDAY THROUGH MONDAY EVENING AND
POSSIBLY INTO EARLY TUESDAY MORNING. INITIALLY...MODEL FORECAST
SOUNDINGS INDICATE THAT CAPPING MAY LIMIT CONVECTIVE ACTIVITY
ACROSS THE FORECAST AREA DURING THE FIRST HALF OF THE DAY MONDAY.
HOWEVER AS LARGE SCALE ASCENT INCREASES WITH THE APPROACH OF THE
UPPER TROUGH...THIS CAP WILL BE OVERCOME WITH DISCREET SCATTERED
CELLS LIKELY TO DEVELOP IN THE AFTERNOON AHEAD OF THE EXPECTED MAIN
SQUALL LINE. STRONG DIVERGENCE ALOFT IS FORECAST OVER THE REGION LATE
IN THE DAY MONDAY AND THROUGH THE EVENING HOURS IN ASSOCIATION THE
RIGHT REAR QUADRANT OF A STRONG UPPER JET ON ON THE EAST SIDE OF
THE TROUGH. DURING THE EVENING HOURS MONDAY...SOUTHWESTERLY MID
LEVEL FLOW OF 50 TO 70 KNOTS WILL TRANSLATE ACROSS THE AREA WITH
85H FLOW AROUND 40 KNOTS. INCREASING SOUTHERLY LOW LEVEL WINDS
WILL YIELD SURFACE DEW POINTS IN THE LOW TO MID 70S AHEAD OF THE
SYSTEM. FAIRLY STRONG SHEAR AND INSTABILITY IS FORECAST TO BE
PRESENT DURING THE EVENT. THE BEST HELICITY VALUES WILL BE IN THE
LATE AFTERNOON. THUS THE BEST CHANCE OF SEEING ANY ISOLATED
TORNADOES WILL BE IN THE AFTERNOON AND EARLY EVENING HOURS MONDAY
WITH ANY DISCREET THUNDERSTORMS THAT DEVELOP AHEAD OF THE SQUALL
LINE. THE SQUALL LINE ITSELF WILL LIKELY MOVE THROUGH FORECAST
AREA FROM WEST TO EAST FROM THE VERY LATE AFTERNOON HOURS MONDAY
THROUGH THE EVENING BEFORE EXITING THE FAR EASTERN SECTIONS OF THE
FORECAST AREA AND THE COASTAL WATERS EARLY TUESDAY MORNING. THE
MAIN THREAT WITH THE SQUALL LINE WILL BE DAMAGING WINDS ALTHOUGH
AN ISOLATED TORNADO CAN NOT BE RULED OUT.

COOLER AND MUCH DRIER CONDITIONS WILL FILTER INTO THE REGION IN THE
WAKE OF THE COLD FRONT TUESDAY. PLEASANT MORE FALL LIKE CONDITIONS
WILL THEN PREVAIL THROUGH THE REMAINDER OF THE WEEK. UPPER LEVEL
RIDGING WILL ATTEMPT TO NOSE INTO THE WESTERN AND CENTRAL GULF COAST
REGION FROM THE WEST FOR THE LAST HALF OF THE WORK WEEK WITH
TEMPERATURES MODERATING SOMEWHAT. A WEAK COLD FRONT WILL ATTEMPT
TO MAKE ITS WAY SOUTH IN THE GULF COAST STATES SATURDAY...BUT WILL
LIKELY STALL OUT NORTH OF THE LOCAL AREA. 11

AVIATION...
EXPECT SCATTERED CONVECTION TO CONTINUE THROUGH THE AFTERNOON AND 
EVENING HOURS. OTHERWISE...EXPECT VFR CONDITIONS TO PREVAIL. A LOW 
STRATUS DECK IS EXPECTED DEVELOP LATER ON TONIGHT. WILL HAVE TO 
WATCH FOR SOME MVFR CONDITIONS OVERNIGHT INTO MONDAY MORNING. HAVE 
NO ADDED MENTION OF THUNDERSTORMS IN TAFS AS THE BULK OF THE 
PRECIPITATION SHOULD FALL AFTER THE VALID TAF PERIOD. 13/MH

MARINE...
SOUTHERLY FLOW WILL INCREASE ACROSS THE COASTAL WATERS THROUGH
MONDAY IN ADVANCE OF A STRONG COLD FRONT THAT WILL TRAVERSE THE
COASTAL WATERS MONDAY NIGHT AND EARLY TUESDAY. A SQUALL LINE IS
EXPECTED TO ACCOMPANY THE FRONTAL PASSAGE. EXERCISE CAUTION
CRITERIA WINDS WILL LIKELY BE OBSERVED ACROSS MUCH OF THE COASTAL
WATERS MONDAY AHEAD OF THE COLD FRONT. IN THE WAKE OF THE
FRONT...OFFSHORE WINDS WILL FLIRT WITH SMALL CRAFT CONDITIONS LATE
MONDAY NIGHT AND TUESDAY. WINDS WILL DIMINISH TUESDAY NIGHT INTO
WEDNESDAY AS HIGH PRESSURE SETTLES ACROSS THE COASTAL WATERS. 11

DECISION SUPPORT...
DSS CODE...ORANGE. 
DEPLOYED...NONE. 
ACTIVATION...NONE. 
ACTIVITIES...SLURRY SUPPORT. MONITORING SEVERE WEATHER THREAT
             FOR MONDAY AFTERNOON AND MONDAY NIGHT. SLIGHT RISK
             FOR SEVERE WEATHER MONDAY AND MONDAY NIGHT.
          
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  69  86  57  75 /  20  70  80  10 
BTR  70  87  58  76 /  20  80  80  10 
ASD  69  86  62  76 /  20  60  80  10 
MSY  72  87  63  76 /  20  60  80  10 
GPT  71  86  65  76 /  20  60  80  20 
PQL  69  86  64  77 /  20  60  80  20 

&&

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

$$