716
FXUS64 KLIX 071724
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1224 PM CDT Sun Jul 7 2024

...New AVIATION...

.SHORT TERM...
(Today through Monday)
Issued at 324 AM CDT Sun Jul 7 2024

It`s not often that soundings come in with 2.3" PW values and only
get isolated development. Suppression that caused the stable
conditions yesterday are still in tact this morning and should
remain that way today. Modeled precip numbers have come more in line
with the actual fcast, so there is a little more confidence in using
these numbers for today. Even though we are not being directly
impacted by Beryl, the indirect effects are being felt in the form
of better subsidence on its outer periphery, so when the system
starts to become better organized then the normal outer subsidence
outside the main core of the system becomes stronger as well. Models
may take some time to catch up with this, but they seem to be coming
in line with this now. Beryl is fcast to come ashore the Texas coast
Monday morning which will start the unwinding process of the system
and subsequently weakening the subsidence on the outside of the
core as well. This should allow for more sh/ts to develop by
Monday. All ingredients are still there for heavy rainfall
producing storms along with waterspouts/landspouts.

Next item will be a heat advisory for today. Dew pt temps at the sfc
will still be in the upper 70s to around 80F coupled with temps well
into the 90s and thin cirrus should allow enough heating to bring up
a heat advisory for today. But this should remain over areas near
and along the interstate 10/12 corridors.

The next item will be coastal flooding. Since Beryl will help bring
an onshore flow with a strong swell train, this will lead to wave
setup along with some piling of water along the shoreline to the
west of the Miss River. Levels are not coming in high enough to
bring up coastal flood headlines at the moment as we will be moving
into a neap tide cycle at the same time. Looking at these levels,
there is about a foot of piling along SW Terrebonne Parish at
Amerada Pass and this drops to around a quarter of a foot of piling
at Port Fourchon. These levels are near but not at or above coastal
flood advisory ranges. But they will need to be watched as any
strengthening of the onshore flow would cause these levels to be a
bit higher. Even if this were to be the case, the numbers would only
allow for a coastal flood advisory and not a warning.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 324 AM CDT Sun Jul 7 2024

Beryl should be around the Texarkana region by Tuesday and as usual
with any tropical system, it should leave a wake trough behind it
which causes an enhancement in the number of sh/ts along this axis.
This process occurs very frequently with exiting tropical systems
and this one will not be an exception. Not much difference in the
attributes with the sh/ts with this troughing as this activity
should still be able to produce heavy rainfall and
waterspouts/landspouts along with some gusty winds commonly in the
40mph range. Not a lot of difference over the next several days and
the fcast will hinge day to day with where this wake trough is
located. We use the term "wake trough", not to be confused with
"wake low". A wake trough is simply a weak trough left in the wake
of an exiting stronger system and normally carries the same
attributes of the dominant system such as PW values, convective
temps, CAPE etc... This trough will help keep a mostly diurnal swing
in precip numbers, but it should also be capable of keeping
convective temps close enough to the water temps to get at least
some morning sh/ts over or near marine areas.

&&

.AVIATION...
(18Z TAFS)
Issued at 1219 PM CDT Sun Jul 7 2024

MVFR ceilings currently in place from expanding CU field should
continue to lift to VFR by or soon after 18Z. Satellite imagery
shows precipitable water over the region is steadily decreasing, now
down to ~1.8". For reference, PW was ~2.2" this time yesterday. With
such relatively dry air moving in combined with subsidence from high
pressure on the periphery of Beryl increasing over the area,
convection should struggle to develop this afternoon at terminals.
Thus, not carrying any in TAFs, though may add VCTS to the airports
closer in higher PW which are KHUM and KBTR.

Lower CIGS and increasing rain chances are expected Monday, mainly
just beyond the extend of this TAF forecast period of 18Z. Before
precip starts, should see southeasterly winds increase quite a bit
with sustained winds around 10 knots and gusts upwards of 20 knots.

MEFFER
&&

.MARINE...
Issued at 324 AM CDT Sun Jul 7 2024

Somewhat higher swell from the south will continue to move through
today and with Beryl a bit closer to the western waters, there will
need to be some headlines mainly for seas, but winds will be in the
15 to 20kt range as well. The highest swell will be west of the Miss
River. Swell heights look to be around 3ft and will be additive to
the wind waves which should be 3 to 4 ft as well making for a total
seas height of 5 to 6 ft with a few 7 footers thrown in. For these
reasons, we will bring up only caution headlines for now, but if
enough swell can make it into these zones and 7ft is achieved, we
may need to move to small craft advisories for these zones. These
numbers will quickly fall as one moves east. This should be the case
through Monday. These conditions will begin to settle by Tuesday
bringing the area back to a normal southerly wind flow around 10kt
for the remainder of the week.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  73  93  75  90 /   0  60  40 100
BTR  79  97  80  94 /  10  60  60 100
ASD  77  94  79  92 /   0  60  50 100
MSY  80  94  81  92 /  10  60  60 100
GPT  79  92  79  91 /   0  60  60 100
PQL  77  95  79  94 /   0  60  40 100

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory until 7 PM CDT this evening for LAZ034>037-039-
     046>048-057-058-060-071-076>087.

GM...None.
MS...Heat Advisory until 7 PM CDT this evening for MSZ068-077-083>088.

GM...None.
&&

$$

SHORT TERM...TE
LONG TERM....TE
AVIATION...MEFFER
MARINE...TE