745
FXUS64 KLIX 080841
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
341 AM CDT Wed May 8 2024

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

.SHORT TERM...
(Today through Thursday Night)
Issued at 330 AM CDT Wed May 8 2024

Today will be a rather dry day across the region with most of the
upper support in the active SW flow aloft staying to our north
over the Midsouth and Tennessee River Valley. The story already
this morning is just how muggy and warm it is outside. At the
time of this AFD in the middle of the night, temperatures are
still around 80F with dew points of 75F leading to a heat index of
85F...Keeping in mind it`s still early May. Today we should warm
a good bit into the lower and middle 90s. Low level flow will
remain out of the south today meaning immediate coast will remain
slightly cooler than inland zones.

On Thursday a strong upper level shortwave will help send a cold
front southward toward the region. During the afternoon, in
response to a modest impulse over central TX, clusters of showers
and thunderstorms are expected to develop along the I35 corridor
and slide eastward within the flow that over our location should
become more zonal as the parent trough aloft continues to
evolve/amplify upstream. These clusters of storms may merge into a
QLCS late Thursday and continue downstream across our region. At
this juncture, low level shear appears to be very modest, but
instability will be on the more moderate to higher end. Globals
and mesoscale models have this QLCS moving through in the early
morning hours generally along and north of the I-12/10 corridor.
This is where SPC has delineated a slight risk of severe
thunderstorms (marginal elsewhere) in the SWODY2. Primary concern
will be strong gusty winds with bowing signatures where mean flow
crosses the QLCS perpendicularly. Additionally, with a bit higher
instability, cannot ignore at least a low-end severe hail threat
as well but this will likely be a secondary concerns. Finally,
given the transient nature of the QLCS, think that flooding
potential will be minimal outside of of typical poor drainage
areas within Baton Rouge. We`ll also need to watch the cold pool
dynamics and how it may impact the speed for the cold front. It
wouldn`t be out of the realm of possibility that the cold pool
will help motivate the FROPA a bit sooner than currently forecast.
(Frye)

&&

.LONG TERM...
(Friday through Tuesday)
Issued at 330 AM CDT Wed May 8 2024

Any residual shower/storm activity lingering over from the short
term period will quickly exit stage east and south. At the
surface, the cold front will continue to drop southward as an
upper level Canadian trough continues to amplify over the eastern
U.S. With lower heights and thicknesses along with low level CAA,
temperatures will be slightly cooler on Friday. That said, above
average temperatures are anticipated to continue especially closer
to the coast. Despite the weak CAA, strong insolation/sun angle
will help keep things on the warm side.

Going into the weekend, a more progressive pattern takes over.
Temperatures start out around average on Saturday and Sunday with
a more zonal flow over the region. However, all eyes begin to
shift upstream later into Sunday. The next H5 shortwave, this one
with Pacific roots, will migrate over the high plains. This will
help the front that pushes through late in the short term period
or early in the long term period lift back closer toward our
region. With surface convergence and perhaps some help from
isentropic upglide, POPs increase later into the weekend and
especially to start the new workweek. One question is how far
north the front will get and how progressive the H5 trough will
be. The surface high takes some time to migrate eastward into the
Mid Atlantic states this weekend and so return flow will be
limited initially. That said, a very moisture rich environment
isn`t far and with the front lifting northward it wouldn`t take
long to moderate the low level moisture profile.

Going deeper into the new workweek next week, it appears that a
series of upper level impulses within the flow move over our
region leading to perhaps periods of showers and thunderstorm
activity. Models are still in a bit of a disagreement with the
exact strength of upper level features and any surface trough/low
development that takes place across the northern Gulf, but
feeling a bit more confident with strong QPF signals despite the
slight disagreements amongst the ECM and GFS. Needless to say
with the increase in cloudiness and rainfall, temperatures will be
held down or more closer to climo norms. (Frye)



&&

.AVIATION...
(06Z TAFS)
Issued at 1152 PM CDT Tue May 7 2024

Moist boundary layer conditions will continue through the entire
forecast period, and this will keep a scattered to broken deck of
strato-cumulus ranging between 2000 and 3000 feet in place through
the afternoon hours. Later tonight, mainly between 08z and 14z,
another weak inversion will form within the boundary layer. The
development of this inversion will allow for lower stratus of 1000
to 1500 feet to develop at the majority of the terminals. However,
at MCB, further stratus build down could occur due to a stronger
inversion layer, and period of IFR ceilings ranging from 300 to
800 feet is in the forecast between 09z and 13z. Increased thermal
mixing after 15z will allow the stratus deck to mix back out into
the scattered to broken MVFR deck much as seen Tuesday. (ME)

&&

.MARINE...
Issued at 330 AM CDT Wed May 8 2024

Winds will gradually increase today through Thursday with
cautionary headlines needed up until a cold frontal boundary
passes through the region early Friday. Behind the front, moderate
winds and seas will continue with northerly flow developing. This
northerly flow will begin to breakdown quickly going into the
upcoming weekend as surface high pressure begins to settle across
our local waters. (Frye)

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  90  72  90  66 /  10  10  20  60
BTR  93  76  94  72 /   0   0  10  30
ASD  91  74  93  71 /   0  10  10  40
MSY  90  77  93  75 /   0   0  10  30
GPT  86  75  89  70 /   0  10  10  40
PQL  88  74  90  69 /   0  10  10  40

&&

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

$$

SHORT TERM...RDF
LONG TERM....RDF
AVIATION...ME
MARINE...RDF