Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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036
FXUS64 KLIX 111329
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
829 AM CDT SAT APR 11 2015

...SOUNDING DISCUSSION...
THE SOUNDING THIS MORNING DEPICTS THE COLD FRONT THROUGH AT THE
SFC WITH NORTH WINDS AND A TEMPERATURE INVERSION FROM 006 TO 013
FT. WINDS THEN SWITCH TO WESTERLY THROUGH THE REST OF THE PROFILE.
PEAK WIND IS 55 KTS AT 150 MB. THE PROFILE IS SATURATED THROUGH
THE INVERSION AT THE SFC AND ALSO NEAR SATURATED FROM 650 TO 460
MB. THIS LEADS TO HIGH OVERALL PW AT 1.73 INCHES... WHICH IS NEAR
THE DAILY MAX IN THE CLIMATOLOGY. THE LAPSE RATE AT MID LEVELS
ALLOWS FOR JUST A BIT OF INSTABILITY FOR ELEVATED THUNDERSTORMS
LATER TODAY WITH 150 J/KG OF ML CAPE AND 580 J/KG MU CAPE.
KRAUTMANN

&&

.PREV DISCUSSION... /ISSUED 321 AM CDT SAT APR 11 2015/

SYNOPSIS...

FRONTAL BOUNDARY HAS DRIFTED SOUTH TO THE SOUTHERN LOUISIANA
COAST...BUT PROBABLY WILL NOT BE GOING MUCH FURTHER. MOST
CONVECTION IS WELL SOUTH OF THE COAST EARLY THIS MORNING. RADAR IS
DETECTING A FEW PATCHES OF RAIN FROM LAKE MAUREPAS SOUTHWESTWARD
TO NEAR MORGAN CITY. AS HAS BEEN THE CASE THE LAST FEW
NIGHTS...SEEING SOME LOW CLOUDS ACROSS PORTIONS OF THE AREA WHILE
OTHER LOCATIONS ARE ONLY SEEING MID LEVEL CLOUDS. TEMPERATURES
RANGE FROM THE LOWER 60S OVER SOUTHWEST MISSISSIPPI TO THE LOWER
70S ALONG THE LOUISIANA COAST.

SHORT TERM...

TODAY WILL BE A RELATIVE LULL IN THE PRECIPITATION. SOUTHWEST FLOW
CONTINUES...BUT NO STRONG IMPULSE AVAILABLE TO PROVIDE ORGANIZED
LIFT. FORECAST SOUNDINGS...HOWEVER...CONTINUE TO SHOW AN UNSTABLE
AIRMASS ACROSS THE AREA. WITH SOME BREAKS IN THE CLOUD COVER
EXPECTED...AND NO CAPPING NOTED IN THE SOUNDINGS...ANTICIPATE
SCATTERED CONVECTION TO DEVELOP...PRIMARILY IN THE AFTERNOON. WHAT
IS LEFT OF THE BOUNDARY SHOULD RETURN NORTHWARD AS A WARM FRONT
LATE TONIGHT AND SUNDAY. WILL HOLD ONTO CHANCE POPS FOR TODAY AND
TONIGHT. MORE ORGANIZED LIFT MOVING TOWARD THE AREA FROM MEXICO ON
SUNDAY AND WILL NEED TO CARRY LIKELY POPS AT THAT TIME. ANOTHER
IMPULSE WILL MOVE ACROSS THE AREA DURING THE DAY MONDAY WITH
ANOTHER PERIOD OF SHOWERS AND THUNDERSTORMS LIKELY. PRECIPITABLE
WATER VALUES WILL BE BETWEEN 1.75 AND 2 INCHES ACROSS THE AREA FOR
SUNDAY AND MONDAY. WHILE WIDESPREAD AREAL QPF VALUES WILL BE BELOW
AN INCH BOTH DAYS...THUNDERSTORMS COULD PRODUCE LOCALIZED RAIN
AMOUNTS WELL IN EXCESS OF 2 INCHES.

TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH MONDAY...BUT DIURNAL
RANGES WILL SHRINK DUE TO CLOUD COVER AND PRECIPITATION. 35

LONG TERM...

ALL THINGS CONSIDERED...MEDIUM RANGE GUIDANCE IS IN RELATIVELY
DECENT AGREEMENT ON LARGE SCALE FEATURES WITH SOUTHWEST UPPER FLOW
CONTINUING THROUGH THURSDAY. MOISTURE CONTENT WILL REMAIN HIGH AND
ANTICIPATE SHOWER AND THUNDERSTORM DEVELOPMENT EACH DAY THROUGH
THURSDAY...MAINLY DURING THE AFTERNOON HOURS LINGERING INTO THE
EVENING. A STRONGER UPPER LOW WILL MOVE OUT OF THE SOUTHERN
ROCKIES FRIDAY...TO EASTERN TENNESSEE BY SUNDAY MORNING. THIS WILL
PUSH A MORE SUBSTANTIAL COLD FRONT ACROSS THE AREA FRIDAY INTO
SATURDAY...DRYING THE AIRMASS OUT CONSIDERABLY FOR NEXT WEEKEND.
WE CANNOT TOTALLY ELIMINATE THE THREAT OF SEVERE WEATHER...WITH
THE LATE WEEK SYSTEM...BUT IT IS A LITTLE TOO EARLY TO PINPOINT A
THREAT AREA OR EXACT TIMING.

TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH NEXT FRIDAY. A
LITTLE BIT OF COOLING BEHIND THE FRONT NEXT SATURDAY...BUT ONLY TO
NEAR NORMAL. 35

AVIATION...

CONVECTION AND LOW CLOUDS WILL BE AN ISSUE AGAIN. CURRENTLY THE
MAIN CONCERN IS LOW CLOUDS AS MULTIPLE TERMINALS ARE DEALING WITH
LOW CIGS...SOME AS LOW AS 400 FT. VSBYS MAY BE AN ISSUE AS WELL
ESPECIALLY AS LGT SHRA CONTINUE TO DEVELOP OVER THE AREA THIS
MORNING. THERE WILL LIKELY BE A BREAK IN THE CONVECTION LATER THIS
MORNING THROUGH AT LEAST EARLY AFTN. BY 20/21Z THE AREA SHOULD
START TO SEE CONVECTION REFIRE WITH SOME STORMS POSSIBLE. /CAB/

MARINE...

COLD FRONT CONTINUES TO SLOWLY SLIDE INTO THE GULF BUT SHOULD
STALL THIS MORNING JUST SOUTH OF THE COAST. WITH THAT WINDS WILL
REMAIN OUT OF THE EAST OVER MUCH OF THE WATERS. THE FRONT WILL
RETREAT BACK TO THE NORTH LATE TONIGHT WITH WINDS RETURNING BACK
TO AN ONSHORE PHASE. A LARGE AREA OF HIGH PRESSURE WILL BECOME
CNTRD OVER THE MID ATLANTIC COAST TIGHTENING THE PRESSURE GRADIENT
OVER THE GULF. THIS WILL FURTHER INCREASE THE WINDS WITH MODERATE
TO POSSIBLY A BRIEF PERIOD OF STRONG ONSHORE WINDS MON. ONSHORE
WILL CONTINUE WELL INTO NEXT WEEK. /CAB/

DECISION SUPPORT...

DSS CODE...BLUE.
DEPLOYED...METS TO AVONDALE AND NEW ORLEANS COMMAND CENTER
ACTIVATION...YES.
ACTIVITIES...FRENCH QUARTER FEST PUBLIC SAFETY SUPPORT
             GRAND PRIX OF LOUISIANA PUBLIC SAFETY 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 TONIGHT RISK SVR
         AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
         SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  80  63  79  67 /  30  30  70  70
BTR  82  66  80  68 /  50  40  70  60
ASD  81  67  80  69 /  50  40  70  60
MSY  81  69  80  71 /  50  40  70  60
GPT  80  69  78  71 /  40  40  70  70
PQL  80  67  79  70 /  40  30  70  70

&&

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

$$



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