589
FXUS64 KLIX 090809
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
309 AM CDT Thu May 9 2024

...NEW SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(Today through Friday)
Issued at 305 AM CDT Thu May 9 2024

Another very muggy night tonight across the CWFA. Here at ASD the
temps are still in the lower 80s and dewpoints are quite juicy
sitting around 76F. Outside of the muggy feels right now, eyes are
certainly looking north with the frontal boundary stretching from
northeast Texas through the Mid South and TN River Valley. Through
the short term period, this front will make its way southward to
our region and eventually through the area early Friday morning.
Before we get into potential convective impacts, it should also be
mentioned that Thursday should be the warmest day for most of the
forecast area with lower and middle 90s anticipated for most land
locations away from the coast.

Okay, so convection. First things first this morning it appears
there could be a few isolated low topped showers develop with the
initial impulse moving into NW Louisiana at the time of this
discussion. The 09/00z RAOB from out back here shows a stout EML,
which should put the cap on anything from growing too much
vertically. Although one outlier CAM did indicate convection
refiring around sunrise from a previous round that has yet to
materialize upstream, so we`ll discount that for now. Through the
day the surface cold front will slide southward over central MS
and AL...which is in line with the mean upper flow slowing the
forward progression just a bit by afternoon. A cluster of
convection is forecast to initiate up stream along the front over
northeast TX by Thursday afternoon. This complex moves quickly
eastward into northern Louisiana and into southern and central MS
during the overnight and predawn hours Friday. Among the globals
and CAM guidance, there is some lowered confidence in terms of
where this cluster or eventual complex winds up. Most global and
CAM guidance has the complex or cluster just north of the CWFA or
across the SW MS Counties. We will continue to monitor the overall
trends and hopefully increase confidence on exactly where this
complex of storms will go.

Now, how severe? Taking a look at the parameters, Instability will
not be a problem anywhere within our forecast area. The question
will be where is the best lift with the H5 impulse and locations
of the front. With roughly 3500 J/KG plus of MLCAPE, hail
potential will be there. The main story will likely be strong
damaging wind gusts especially with bowing segments of the line.
Speaking of, a mesovort or two wouldn`t be impossible with
somewhat favorable 0-3km line normal bulk shear present, but
overall given the likely orientation of the MCS the potential
would likely be on the lower side...not zero but low. PWATs around
2.0" or so will also be present, but hydro concerns will be mostly
limited given the more short duration/transient nature of the
complex. Bottom line here is damaging wind seems to be the biggest
threat with the strong west to east flow aloft.

The front moves through Friday and winds shift to a more northerly
direction. Although by definition CAA initiates, we will still see
some locations especially the southern most spot warm into the
middle and upper 80s or perhaps touching 90 degrees along the
Mississippi Gulf Coast during the afternoon, especially if clouds
depart rather quickly. (Frye)

&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 305 AM CDT Thu May 9 2024

In the wake of the FROPA, cooler nights as well as drier days will
materialize. The region will be under a slightly drier WNW flow
aloft Friday Night through early Sunday. From this point forward
eyes again shift up to the Texas Hill Country where another upper
level shortwave will be amplifying. As it does, the general flow
becomes zonal across our region. Ahead of the amplifying trough,
our cold front that eventually stalls over the central Gulf will
begin to lift forward as a warm front Sunday, Sunday night and
into early Monday. Ahead of the front some isentropic upglide will
help generate showers and perhaps some elevated convection across
the CWFA. As the upper level disturbance moves eastward across
east TX within the zonal flow, rain chances will gradually
increase. A series of upper level short waves will develop within
the newly established SW flow around the slowly approaching
broader upper level trough. This is likely going to produce a
source for additional waves of showers and thunderstorms through
the start of the new workweek prior to the broader trough ejecting
northeast eventually toward the Mid Atlantic sending yet another
front through the region and shutting off the rain chances by
Wednesday. Temperatures in the long term look to hang around
seasonal averages or perhaps slightly cooler with the lower
heights and increased cloud cover reducing insolation. (Frye)

&&

.AVIATION...
(06Z TAFS)
Issued at 1140 PM CDT Wed May 8 2024

Primary condition at forecast issuance time will be MVFR ceilings,
but at times, that deck scatters out to VFR conditions. While most
of the night will see MVFR ceilings, there may be periods where
ceilings fall to about FL008, especially at KMCB and perhaps KHDC.
Those MVFR ceilings will remain common until midday, when the
cumulus field may scatter out as bases lift to FL030 or a little
above. Cloud bases will again lower to MVFR after sunset Thursday
with the loss of heating. Still some uncertainty whether TSRA
progresses far enough southward, or quick enough, to impact this
forecast package. If it reaches KMCB or KBTR during the forecast
package, it would be only in the last hour or two (04z or beyond),
and there are some solutions indicating that`s too quick. Will
hold off mention for this package, but 12z package will reassess.
(RW)

&&

.MARINE...
Issued at 305 AM CDT Thu May 9 2024

A cold front will continue to move southward toward the central
Gulf Coast today and should move through later tonight or early
Friday. Ahead of the front southerly winds will remain moderate to
strong through the early morning hours. A SCA has been issued for
all waters outside of the Lake. As the front nears, the pressure
gradient will relax a bit. Mostly moderate winds will be expected
so cautionary headlines may be needed at some point Thursday and
then again behind the front on Friday. Winds and seas will calm
over the weekend as high pressure moves eastward to our north.
However, another upper level disturbance will engage the front
that pushes south into the Gulf later this weekend and through the
start of the new workweek...leading to higher convective chances
and perhaps locally higher winds and seas. (Frye)

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  90  66  83  58 /  20  40  20   0
BTR  94  72  89  64 /  10  20  10   0
ASD  92  71  88  62 /  10  30  30   0
MSY  92  75  89  69 /  10  20  20   0
GPT  89  71  89  63 /  10  50  40   0
PQL  90  71  90  60 /  20  50  40   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...Small Craft Advisory until 7 AM CDT this morning for GMZ532-534-
     536-538-550-552-555-557-570-572-575-577.

MS...None.
GM...Small Craft Advisory until 7 AM CDT this morning for GMZ534-536-
     538-550-552-555-557-570-572-575-577.

&&

$$

SHORT TERM...RDF
LONG TERM....RDF
AVIATION...RW
MARINE...RDF