685
FXUS64 KLIX 252112
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
412 PM CDT Wed Sep 25 2024

...New SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(This evening through Thursday night)
Issued at 402 PM CDT Wed Sep 25 2024

KEY MESSAGE: Hurricane Helene is entering the southern Gulf of
Mexico and is expected to make landfall Thursday evening in the
Panhandle of Florida. If you have interests whether it be property
or friends or family in these areas, ensure they are prepared for a
a Category 3 hurricane or even higher. Preparations for the storm
should be rushed to completion and if you have been ordered to
evacuate please do so.

While all eyes are on Helene entering the GOMEX this afternoon,
we have had a weak frontal passage that has sparked up some shower
and thunderstorm activity. Anomalously cold mid-level
temperatures in association with a deep, cut-off upper low over
the lower MS Rivey valley are aiding in steeper lapse rates
capable of stronger updrafts. Thus far, we have seen a few
thunderstorms across Tangipahoa, Livingston, and St. Tammany
Parishes take advantage of this more favorable environment and
produced some hail and gusty winds. The storm over St. Tammany in
particular produced a microburst which caused tree and roof damage
near Mandeville and Covington. These showers and storms will
gradually work their way to the southshore and coast, but
predominantly will be isolated and short-lived in nature. These
showers and storms will die out after sunset and we`ll see drier
and cooler air gradually advect southward overnight allowing
temperatures to cool slightly.

&&

.LONG TERM...
(Friday through Tuesday night)
Issued at 402 PM CDT Wed Sep 25 2024

More appreciable advection of drier air from the north
will start on Wednesday and continue through Thursday as the
pressure gradient tightens with Hurricane Helene passing to the east
of the area. Aside from the mid-upper level clouds from the outer
edges and outflow layer from Helene, skies will be fair providing a
stretch of downright beautiful fall days across our area into the
weekend. Highs will be seasonably in the mid 80s with lows in the
60s inland to near 70F across the southshore.

The long range pattern remains fairly dry and seasonable across the
area into next week with lingering upper troughing keeping mid-level
temps cooler and surface high pressure over the Plains keeping a
steady stream of northerly winds. A reinforcement of this regime
takes place on Tuesday as a shortwave trough kicks through and the
post-frontal high brings another surge of continental dry air down
into the area, right on cue for October (our climatologically driest
month).

Lastly, even with Hurricane Helene entering the Gulf today, we might
hear whispers and see clickbait online of more Gulf tropical
mischief on the horizon 7 to 10 days out. There is some truth to
this as a tropical wave nearing the Lesser Antilles will need to be
monitored as it moves into the western Caribbean next week which is
what is being picked up on by the global model guidance over the
past couple of days. However, it`s still too far out to know exactly
where this disturbance will track or if it will even have the chance
to develop yet. For now, just stay tuned to the latest tropical
weather outlooks.

&&

.AVIATION...
(18Z TAFS)
Issued at 1249 PM CDT Wed Sep 25 2024

A few SH/TS in association with a weak frontal boundary have
provided brief impacts to HDC and ASD over the last couple hours.
Expect the front to continue to sag into the coastal waters and
have VCSH/TS groups this afternoon for this period with the
passage. Otherwise, VFR conditions with northerly winds are
expected overnight. Could have brief MVFR conditions at sunrise in
MCB with ground fog, but otherwise dry and benign convective
conditions into Wednesday with winds increasing out of the north
in excess of 10-15 knots with gusts up to 20 knots by the end of
the period.

&&

.MARINE...
Issued at 402 PM CDT Wed Sep 25 2024

Winds and seas will begin to build overnight tonight as the
pressure gradient tightens with encroachment from Hurricane
Helene. Offshore winds will intensify to 20 to 30 knots especially
over the outer coastal waters beyond 60 NM out. SCA remains in
effect with possibility of Gale conditions in outer most waters
where gusts could be in excess of 35 to 40 knots and wave heights
could build as high as 15 feet. Have kept Gale watch in effect for
the possibility of these conditions on Thursday. Helene will push
inland on Friday with winds shifting to westerly in its wake.
Unsettled marine conditions will gradually improve by Friday
afternoon as the pressure gradient relaxes. Conditions continue to
gradually improve through the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  64  83  60  80 /  10   0   0   0
BTR  69  88  64  85 /  10   0   0   0
ASD  69  86  64  84 /  10   0   0   0
MSY  73  86  67  84 /  10   0   0   0
GPT  69  85  65  84 /  10  10   0   0
PQL  71  87  66  86 /  20  10  10   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...Small Craft Advisory until 4 PM CDT Friday for GMZ530-532-534-
     536-538-550-552-555-557-570.

     Small Craft Advisory until 7 AM CDT Thursday for GMZ572-575-577.

     Small Craft Advisory from 1 AM to 4 PM CDT Friday for GMZ572-575-
     577.

     Gale Watch from Thursday morning through late Thursday night for
     GMZ572-575-577.

MS...None.
GM...Small Craft Advisory until 4 PM CDT Friday for GMZ532-534-536-
     538-550-552-555-557-570.

     Small Craft Advisory until 7 AM CDT Thursday for GMZ575-577.

     Small Craft Advisory from 1 AM to 4 PM CDT Friday for GMZ575-577.

     Gale Watch from Thursday morning through late Thursday night for
     GMZ575-577.

&&

$$

SHORT TERM...TJS
LONG TERM....TJS
AVIATION...TJS
MARINE...TJS