520
FXUS64 KLIX 051734
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1234 PM CDT Fri Jul 5 2024

...New AVIATION...

.SHORT TERM...
(Today through Sunday)
Issued at 428 AM CDT Fri Jul 5 2024

It has been fairly quiet over night but it is very muggy and warm
out there. For the last few hours it appears most sites have
stopped falling with everyone in the upper 70s to mid 80s still at
08z and with most locations sitting at 91-97% rh already we will
likely not see much more of a temp fall this morning. This will
set the stage for a very warm start to the day as most of the area
will heat up quickly before convection starts to develop which
will help to cool things down some.

So the forecast problems today, heat and convection. The convection
is multi-faceted as timing and coverage will have pretty significant
influence on the temps and subsequent heat. By 8z there was less
coverage on radar than the previous night and convection was able to
develop very quickly yesterday. That said we are finally beginning
to see some showers pop up and storms will likely be able to develop
quickly. But most of the activity will be highly dictated by
boundaries. One key feature that will aid convection to develop,
especially early, is the amount of moisture in place. PWs will
remain very high around 2.5" and this extremely high. Then ridge
over the area will continue to remain in place but it is beginning
to weaken some so hghts have lowered and mid lvl temps have cooled
relatively.

By late morning storms should begin to fire off of the seabreeze and
then additional storms will develop off of outflow boundaries from
the first few storms along. Storms are most likely to develop along
any boundary collisions and doesn`t matter whether multiple outflow
boundaries, outflow and lake/sea breeze, or sea and lake breeze
collisions. These is likely to happen after most of the area warms
up but if storms can really become a little most widespread many
locations would likely struggle to warm up enough to get those
rather high oppressive conditions. Heat advisory was issued
yesterday for mainly the areas surrounding the tidal lakes and
coastal MS but we have now expanded it north to include all of the
area north of I-10 and this includes southwestern MS. Those sections
which are in southwest MS and the adjacent LA parishes may actually
have the better chance of seeing heat advisory criteria as rain
could hold off for quite some time, and that could be a weak
boundary moving in from the north.

Speaking of that boundary it will not be in a huge rush to get here
as the ridge in the mid lvls even though will be weakening is still
going to dominate the region through Saturday. The boundary/front
should begin to push into the region late this afternoon and early
evening but it will continue to slow down and should eventually
stall over the area. This boundary could be a focus of storms
development not just later today but especially so on Saturday and
even Sunday. In fact the boundary could help convection develop very
early Saturday and it is because of that uncertainty and possibility
we are holding off on another heat headline for Saturday. With the
amount of moisture in place we will not cool much or quickly so once
again Saturday and sunday will have a very warm jumping off point to
begin the day. If convection is delayed then we warm up faster than
expected and multiple locations could be dealing with the oppressive
heat index readings through the weekend. /CAB/

&&

.LONG TERM...
(Monday through Thursday)
Issued at 428 AM CDT Fri Jul 5 2024

The extended forecast remains warm but we should be out of the
oppressive conditions. Afternoon highs should be a touch cooler
but still just above normal. Morning lows will remain awful as
moisture will remain abundant in all lvls of the atmosphere. As
for Beryl latest forecast have shifted north some with landfall
expected sometime Monday over the Lower TX Coast.

The ridge that we have talked about all week and in the first half
of this discussion should be centered off to the east now around the
northeastern Gulf Monday and into Tuesday. This is going to allow
Beryl to make that turn to the northwest sometimes Saturday and
through Sunday. How soon that happens will make a huge difference to
multiple impacts across TX but overall for our area we are still
not expecting ANY DIRECT IMPACTS. That said indirect impacts could
be creeping up. The two biggest which we have mentioned over the
previous days will be increasing winds over the coastal waters and
elevated tides. This still looks like a good possibility but one
other thing to watch could be rainfall. If Beryl continues to trend
to the right due to the shape of the TX coast and approach of Beryl
landfall locations could be off by a lot even though the track is
only off by a few miles. The issue with that is that we could see a
focused surge of moisture on the east side of Beryl move into LA and
this band of moisture would likely be oriented north to south and if
that occurs there is a good chance that training of tropical showers
will accompany it and where that band sets up will be key. These
features can setup well east of the main tropical system so we will
need to watch this and see if that sets up over our area. /CAB/

&&

.AVIATION...
(18Z TAFS)
Issued at 1230 PM CDT Fri Jul 5 2024

Afternoon pop-up convection will be the primary concern today at
all of the terminals. The highest probabilities for convective
activity will be between 22z and 01z, and have TEMPO groups of
TSRA with IFR visibilities during this time period at the majority
of the terminals. The convecive activity is expected to quickly
diminish after 01z as daytime heating wanes. At MCB, the risk of
another weak inversion and LIFR ceilings is high enough to
include in the forecast from 09z to 13z. MVFR visibilties of
around 3 mile will accompany these low ceilings. HUM may also see
fog and low stratus development over the same period of time, but
have opted to not include it in the forecast at this time as
probabilities of occurrence are lower.  PG

&&

.AVIATION...
(06Z TAFS)
Issued at 1141 PM CDT Thu Jul 4 2024

Most terminals were VFR at 05z, however, there were a few with
visibility restrictions. Considering how many communities have had
fireworks this evening, some question whether it`s fog/mist or
smoke in some areas. Regardless, will carry some visibility
restrictions as appropriate. Will mention IFR visibilities toward
sunrise at KMCB, where they had similar conditions this morning,
and additionally, had 2 inches of rain in the area during the day.

Likely to see MVFR ceilings and SHRA at southern terminals,
as early as 10z or so, but spreading to most or all terminals by
mid-morning. In most cases, precipitation won`t be particularly
long lasting at any one time, as with no wind shear to speak of,
the showers/storms are likely to rain themselves out in place.
Moisture levels are pretty much at climatological maxima with
precipitable water values near 2.5 inches. That combined with
forecast convective temperatures near 90F, means it is unlikely
for terminals to keep unrestricted ceilings/visibilities for
significant periods during daytime heating. MVFR ceilings likely
to be prevailing for most of the day. For now will use VCTS during
the afternoon hours at all terminals, but later shifts will
likely need to do occasional amendments for direct impacts at a
few terminals. IFR or lower visibilities will occur if a terminal
is directly impacted. As has been the case for the last several
days, most land based convection will dissipate by 01z Saturday,
if not sooner. /RW/

&&

.MARINE...
Issued at 428 AM CDT Fri Jul 5 2024

High pressure continues to dominate the region and will continue
to through Saturday. This will keep the light winds and low seas
in place. By Sunday the sfc high will push off to the east while
Hurricane Beryl works northwest across the western Gulf. This
should lead to moderate onshore flow setting up late Saturday
through the weekend and into next week. Can`t rule out some
possible SCY headlines by Sunday. Tides will likely be elevated
but at this time it doesn`t looks like any significant coastal
flooding should occur. Other and probably the greatest impact will
continue to be convection mainly during the overnight/early
morning hours. With any storm locally higher winds and seas along
with a few waterspouts are expected. /CAB/

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  74  89  73  91 /  60  60  20  60
BTR  78  94  79  95 /  70  60  20  60
ASD  78  94  77  94 /  60  60  30  70
MSY  81  93  81  94 /  70  60  30  70
GPT  78  92  77  92 /  50  70  40  60
PQL  77  96  77  95 /  40  70  40  60

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory until 6 PM CDT this evening for LAZ034>037-039-
     046>048-056>060-064-065-071-076>090.

GM...None.
MS...Heat Advisory until 6 PM CDT this evening for MSZ068>071-077-
     083>088.

GM...None.
&&

$$

SHORT TERM...CAB
LONG TERM....CAB
AVIATION...PG
MARINE...CAB