694
FXUS64 KLIX 272326
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
626 PM CDT Sat Apr 27 2024

...New AVIATION...

.SHORT TERM...
(This evening through Monday night)
Issued at 338 PM CDT Sat Apr 27 2024

Generally speaking, upper level ridge is in place across the eastern
third of the country and an upper trough covers the rest of the
country. The CWA is currently on the western side of the ridge.
Steadily onshore flow has brought in quite a bit of low level
moisture with dewpoints in the mid 60s to lower 70s. Due to this and
NBM being slightly too cool last night, went ahead and bumped up
overnight lows slightly. That`ll give us a warm start to Sunday with
most locations having lows around 70 degrees. Model soundings show
PW`s still quite low, not much over 1", except for along the MS
coast. It`s here that slightly higher column moisture as well as
moisture convergence along the coast combined with diurnal heating
will allow for scattered showers to develop. Based on this and
agreement from global models, have increased the areal extent of
last night`s forecast rain on Sunday.

A bit more complex setup looks to develop on Monday related to the
upper level trough currently draped across the Rocky Mountains.
Models show the base of this trough rotating northeast Sunday with a
closed low moving through the upper Mississippi Valley Monday. At
the same time, a piece of energy breaks off the southwestern side of
the trough and heads due west towards the Lower Mississippi Valley.
It`s this shortwave that`ll initiate stronger convection in north
Louisiana Monday morning. All the CAMs, and even the global models,
show an MCS developing there, cold pooling and diving southeastward.
The 2 questions are what`s its actual trajectory going to be and how
strong will it be when it gets closer to the Gulf Coast. Model
soundings show sub-severe wind shear but more than ample CAPE.
That`s completely expected with a weak shortwave driving the show
and late spring temps in place. Thus, think timing will play a big
factor in if the MCS is able to capitalize on instability in place.
How soon it starts to cold pool will be a big factor on if it dives
south across southwest LA or southeast LA and southern MS. Thus,
SPC`s marginal outlook is quite appropriate for this potential
event.


&&

.LONG TERM...
(Tuesday through Friday night)
Issued at 338 PM CDT Sat Apr 27 2024

Tuesday sees us right in the middle of upper level northern and
southern flows with very gentle troughing over the western CONUS and
weak ridging over the eastern Pacific across northern Mexico and
into the northern Gulf.  At the surface we have the Bermuda high in
the western Atlantic and low pressure over the western US down into
Mexico.  Several shortwaves move through the upper levels as the
week progresses, drawing moisture into the area and giving us
several chances for rain.  The greatest chance is on Tuesday with
PoPs around 50% and forecasted amounts generally around 1/3 of an
inch.  It doesn`t look like any severe weather will accompany the
rain.  Temperatures start a bit above normal with lows in the mid-
60s to low 70 and highs in the low to mid 80s.  By the weekend we
are looking at highs in the mid to upper 80s.  Winds should be out
of the south to southeast and 10-15mph.


&&

.AVIATION...
(00Z TAFS)
Issued at 623 PM CDT Sat Apr 27 2024

Strong east-southeasterly flow will continue to impact all
terminals for the entire forecast period. Winds will shift
slightly more southeasterly as the approaching cold front get
closer towards the end of the period. Low-level moisture advection
ahead of the front could cause some patchy MVFR ceilings tomorrow
morning before daybreak. Once the sun comes up, those low ceiling
should break up and VFR conditions return for the rest of the
period.

&&

.MARINE...
Issued at 338 PM CDT Sat Apr 27 2024

A surface ridge centered in the western Atlantic Ocean just off the
East Coast. It`ll remain there throughout the forecast period.
That`ll keep onshore flow entrenched. The local pressure gradient
between that feature and deepening low in the Central Plains has
increased winds and seas/waves into Small Craft Advisory. Expect
those conditions to persist through this weekend. Have made a 12
hour extension to the advisory based on latest forecast winds.
Otherwise, a slight weakening in the gradient will allow for winds
to fall into Exercise Caution next week.


&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  66  82  68  80 /   0  20  10  80
BTR  71  88  73  85 /   0  10  10  80
ASD  69  83  70  84 /   0  20   0  50
MSY  72  84  73  85 /   0  10   0  60
GPT  70  80  70  81 /   0  30   0  30
PQL  67  82  68  84 /   0  20   0  20

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Wind Advisory until 9 PM CDT this evening for LAZ034>037-039-
     046>048-056>060-064>071-076>090.

     Coastal Flood Advisory until 7 PM CDT Sunday for LAZ058-070-076-
     078-080-082-084.

GM...Small Craft Advisory until 7 AM CDT Monday for GMZ530-532-534-
     536-538-550-552-555-557-570-572-575-577.

MS...Wind Advisory until 9 PM CDT this evening for MSZ068>071-077-
     083>088.

     Coastal Flood Advisory until 7 PM CDT Sunday for MSZ086>088.

GM...Small Craft Advisory until 7 AM CDT Monday for GMZ532-534-536-
     538-550-552-555-557-570-572-575-577.

&&

$$

SHORT TERM...ME
LONG TERM....DS
AVIATION...JZ
MARINE...ME