573
FXUS64 KLIX 251137
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
637 AM CDT Tue Jun 25 2024

...New AVIATION...

.SHORT TERM...
(Today through Wednesday)
Issued at 325 AM CDT Tue Jun 25 2024

Upper ridging extended from southern California to western
Louisiana early this morning with troughing just off the Atlantic
Coast to the northeastern Gulf of Mexico. There was a shortwave
moving through the western Great Lakes and another over Nebraska
and Kansas.

Temperatures at 3 AM CDT were in the 70s across most of the area.
There were a few showers over the Gulf of Mexico to the south of
the Mississippi coast, which isn`t all that unusual for this time
of year.

The primary concerns over the next 36 hours will be the heat, and
the potential for thunderstorms. While the shortwave that
triggered yesterday`s thunderstorms has moved away from the area,
there will still be remnant outflow boundaries around. As
temperatures heat up into the middle 90s in most areas by midday,
we should see at least isolated to scattered development of
storms. Low level wind fields are pretty weak, so any storms that
develop today won`t be moving much, just propagating along
outflows. Most storms should die out by sunset. Before the
thunderstorms develop, conditions are likely to be pretty
oppressive with heat index values approaching, if not exceeding
110F in many areas. Will keep the Heat Advisory in place for
today.

The one change on Wednesday as compared to today is that a
shortwave moving out of the Plains states will move into the area
around midday, which is expected to enhance areal coverage of
showers and storms during the afternoon into the early evening
hours. Depending on the timing of convective development, it could
keep our heat index values just below advisory criteria tomorrow.
We won`t extend the advisory beyond this afternoon for now, but
there`s certainly potential that we will need one, especially west
of Interstate 55.

As there isn`t much spread in the guidance, will not make
significant departures from the NBM deterministic for now.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 325 AM CDT Tue Jun 25 2024

We may still have shortwave energy impacting the area on Thursday
with ridging well to the west of the area. That would lead to
fairly good areal coverage of storms across the area, and
potentially be the least uncomfortable day of the extended. Beyond
Thursday, both the GFS and ECMWF operational runs build the ridge
back toward the area. At this point, the main question is whether
the ridge builds over the local area or just to the north of the
area. If it builds over the area, it would limit any significant
development of thunderstorms, and allow for hotter daytime
temperatures. If it becomes centered to the north of the area, it
may allow for at least some afternoon convection, especially near
the coast. At this point, the more favored solution would allow at
least some thunderstorm development during the afternoon hours and
hold high temperatures in the middle 90s.

&&

.AVIATION...
(12Z TAFS)
Issued at 625 AM CDT Tue Jun 25 2024

All forecast terminals VFR at forecast issuance time, although
there may be some MVFR ceilings to the south of the New Orleans
terminals over the next few hours. There are isolated SHRA/TSRA
between KBVE and KHUM that really aren`t moving much. The current
activity may dissipate in the next few hours, but forecast
soundings are supportive of at least isolated development near or
after maximum heating at midday or shortly after. Convection
allowing models definitely not in agreement regarding the extent
of storms this afternoon, as large scale forcing is not apparent.
More likely mode is differential heating along boundaries such as
lake/sea breeze boundaries and remnant boundaries from yesterday`s
storms.

Will carry VCTS this afternoon at all terminals except KMCB, but
confidence in a particular terminal is not high. If there are
direct impacts at a terminal it would most likely be IFR
visibilities and wind gusts around 30 knots. Any convection that
does develop should wind down near or shortly after 00z. For now,
will not carry any visibility restrictions around sunrise
Wednesday, as fog development will be rather dependent on rainfall
which hasn`t occurred yet.

&&

.MARINE...
Issued at 325 AM CDT Tue Jun 25 2024

No large scale pressure systems are expected to impact the coastal
waters over the next several days. So, outside of the usual
diurnal increase in wind speeds during the evening hours, the only
real concern will be the development of thunderstorms. Generally,
that would impact the tidal lakes and sounds during primarily the
afternoon and evening hours and the open waters during the late
night and early morning hours.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  94  74  92  74 /  30  20  60  40
BTR  97  78  96  78 /  50  20  60  30
ASD  96  77  94  77 /  40  20  60  30
MSY  94  79  93  79 /  50  20  70  30
GPT  95  78  94  77 /  30  20  60  40
PQL  98  77  96  77 /  20  20  50  40

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for LAZ034>037-039-046>048-056>060-064-065-071-076>090.

GM...None.
MS...Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for MSZ068>071-077-083>088.

GM...None.
&&

$$

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