556
FXUS64 KLIX 030850
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
350 AM CDT Mon Jun 3 2024

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

.SHORT TERM...
(Today through Tuesday)
Issued at 347 AM CDT Mon Jun 3 2024

Sooooo, there is literally not one model that actually "sees" this
MCS from the 00z runs that has been moving across the entire state
of LA and now well through southern Miss. One would think that at
least one of the CAMS would initialize on this, but not yet. So we
will look to the synoptic overall large scale view to see what is
occurring and what should occur. Two ThetaE gradients stick out this
morning. One is at 1000mb and the other at 850mb. The 1000mb
gradient is still snaking near the coast of LA westward into central
TX. This is where the southern extend of the current MCS is riding
along. The other is at 850mb and is where the northern extent is
riding along. There are no other mechanisms that would cause this
MCS to decay this morning, at least for now. But between 9z and 12z,
these two boundaries are supposed to begin moving northward leaving
the MCS behind. This would cause this complex to slowly weaken and
decay, but we will need to see if that actually occurs. Have brought
precip numbers way up than what the NBM has as its first guess(5%
vs. 60%) and bring these numbers back toward the NBM numbers as the
morning progresses. So we are coming out of right field and the NBM
out of left.

As these boundaries move northward and leave the gulf coast, this
should help keep at least the MCS features to the north. With that
being said, the next one is getting going now over the northern
panhandle of TX and into OK this morning. This one will follow
almost the same path as the previous except it will begin to feel
this tug of the boundaries northward then collapse as the gradient
orients meridionally. This is because the boundaries will become
oriented perpendicular to the storm flow. The MCS can continue to
propagate downstream as long as they can follow these moisture
gradients(parallel to storm flow), but when the gradients become
north-south and the storm flow is ESE, it causes these complexes to
run through this boundary instead of along it causing it to
collapse. This does not mean there will be no sh/ts around today,
there will still be boundaries and other means for sh/ts to develop
over the area today. It just means that these big complexes should
be farther north of the area after today instead of directly causing
our storms. The big noteable difference will be late today. And this
is also where there will be questions in storm development/movement
today. The 850mb ThetaE gradient rapidly develops along the coast of
the entire gulf today around noonish. Now, if there are any storms
that can flow along this gradient, they could actually grow as they
move eastward. But, this won`t be long lived because this boundary
will develop and move with the large scale synoptic pattern. This
means it will develop quickly, and like a strong sea brz(which it is
not), it will rapidly move northward away from the gulf coast
starting around 4pm and should be in northern LA/MS by midnight
tonight. This shows the opening up of the entire deep south which
means an end to these MCS features running rampant into our area
before dying. This is also an indication of the large scale synoptic
pattern bringing larger scale forcing into the picture which will
flush all this mess northward instead of eastward like we normally
see with systems in the westerlies. This will all be due to an upper
trough digging into the central CONUS and delivering a cold front to
the upper plains. This simply causes all the air from the gulf to
the central states to flow into this front bringing these gradients
and the deep moisture northward. This used to be called moisture
loading ahead of a front. But it helps us as it should bring all
these conditions that support the infinite chain of MCSs northward
for at least several days.

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 347 AM CDT Mon Jun 3 2024

One may think the cold front we are talking about is the one with
the sfc low just east of Winnipeg that has a frontal boundary from
there southward into Nebraska. This is the front that will begin to
move everything northward from the gulf coast later today, but it is
not the main cold front we are discussing, that one is just getting
developed over the Canadian Rockies this morning. We should see the
first indication of this front over eastern Montana late today or
overnight tonight. This front will keep all of these boundaries
north of the area while it is digging southward and should be near
or stalling over the area by the weekend. Now, this front should
make its way to our area by Fri or Sat, but where it stalls will
dictate our fcast from there as it will cause all of these
boundaries as well as itself to be located from here(or wherever it
stalls) back into the flatlands of TX/OK. And you guessed it, the
train of MCS would start all over again. We will need to see how
this plays out first, but we should have a few days for things to
dry out first.

&&

.AVIATION...
(12Z TAFS)
Issued at 347 AM CDT Mon Jun 3 2024

VFR will be found at most terminals today outside of the morning
TSRA we are experiencing now. IFR cigs could be found through mid
morning for MCB but the rest of the are should be in VFR. There is a
good chance of terminals being impacted by TSRA during the afternoon
hours as well. Tonight should play out fairly similar but without
the MCS that is moving over this morning.

&&

.MARINE...
Issued at 347 AM CDT Mon Jun 3 2024

Southerly winds of 10-15kt will remain over all waters through much
of this week. Winds could become more westerly by the end of the
week but wind speeds shold remain light outside any storms that
develop.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  86  70  89  71 /  50  30  30   0
BTR  91  75  92  75 /  40  10  30   0
ASD  89  74  90  75 /  20  20  30  10
MSY  89  77  90  77 /  30  10  30   0
GPT  88  77  88  77 /  20  10  40  10
PQL  89  74  89  74 /  20  10  20  10

&&

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

$$

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