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

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000
FXUS64 KLIX 191737
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1237 PM CDT Wed Sep 19 2018

.AVIATION...
VFR conditions outside of scattered convection this afternoon
and again Thursday afternoon. Convective temperature of 91F pretty
much achieved at all locations. Gust potential 20-30 kt. Slow
movement of cellular storms may yield a period of torrential
rainfall with visibilities lowering to 1/4SM for about 15-20
minutes. 24/RR

&&

.PREV DISCUSSION... /issued 801 AM CDT Wed Sep 19 2018/

SOUNDING DISCUSSION...
This morning`s balloon launch was successful, and there were no
issues. The balloon popped at 8.41 millibars. Looking at the
sounding, the overall vertical atmospheric profile is dry. There
is a temperature inversion at the surface that will likely
dissipate throughout the day as atmospheric mixing occurs. The
CAPE is average for this time of year (1437 J/kg in the mixed
layer), and the CIN is average for this time of year (-64 J/kg in
the mixed layer).This combination will lead so some typical
afternoon showers scattered in the area throughout the day. The
vertical wind profile is mostly uniform with height. At the
surface, the winds are northerly and light (5 knots). At the
lower, middle and upper levels, the winds are primarily easterly
and light (15 knots in the jet stream). MSW

PREV DISCUSSION... /issued 347 AM CDT Wed Sep 19 2018/

SHORT TERM...
Deeper moisture will begin to move back into the area through the
remainder of the week. But we will have to get through today and
possibly Thursday with the heat. Temps should climb well into the
90s again today putting records once again in jeopardy. No one was
under 95F yesterday except Boothville. Last effort for summer to
hang on. Better chances of sh/ts will likely be welcomed as they
will help cool things down a bit. A cold front will move toward
the area over the weekend and stall to the north. But this will
help draw moisture from the gulf up through Texas and Louisiana to
keep the area in relatively higher chances of rain through much of
next week. And with mid level dry air still over the area, an
isolated strong or severe thunderstorm is always a possibility.

AVIATION...

Expect VFR conditions for all area terminals early this morning.
Only exception is KHUM where patchy light fog has developed early
this morning, creating MVFR to IFR conditions. Fortunately, all
areas of fog should diminish shortly after sunrise with VFR
conditions returning. Otherwise, look for afternoon storms to re-
develop again around 18-19Z but should be isolated in coverage.
Better chances will be across SE LA across KHDC to I-10 including
KMSY and KASD. Any one storm today could be locally strong, with
gusty, erratic downdraft wind gusts up to 20 to 30mph and dangerous
lightning. Locations farther north will see less coverage due to
much drier air aloft filtering in. KLG

MARINE...

A weak area of high pressure continues to drift to the east across
the NE GOMEX, which will continue to cause a steady increase in
onshore flow during the day today. Winds will still be relatively
light, ranging 5-10kts with slightly higher gusts. Winds will
continue increase through Thursday and Friday from the SE with gusts
up to 15 to 20kts at times, generally west of the MS delta.
Additionally, isolated marine convection increases in coverage into
late week and the upcoming weekend, with best coverage in the
overnight hours. Any one storm could contain gusty, erratic winds
and dangerous lightning.  KLG

DECISION SUPPORT...

DSS code: Green.
Deployed: None.
Activation: None.
Activities: None.

Decision Support Services (DSS) Code Legend
Green  = No weather impacts that require action.
Blue   = Long-fused watch, warning, or advisory in effect or
         high visibility event; Marginal risk severe or
         excessive rain.
Yellow = Heightened impacts with short-fused watch, warning or
         advisory issuances; radar support for Slight risk severe
         or excessive rain.
Orange = High Impacts; Enhanced risk severe; nearby tropical
         events; HazMat or other large episodes.
Red    = Full engagement for moderate to high risk of severe
         and/or excessive rain; direct tropical threats; Events
         of National Significance.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  96  72  92  72 /  10  10  30  10
BTR  96  74  93  74 /  20  10  30  10
ASD  96  74  92  75 /  30  10  30  20
MSY  95  77  91  77 /  30  10  30  20
GPT  94  76  90  76 /  30  10  20  20
PQL  95  74  91  75 /  30  20  20  20

&&

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

$$


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