998
FXUS64 KLIX 122255
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
555 PM CDT Mon Aug 12 2024

...New AVIATION...

.SHORT TERM...
(This evening through Tuesday night)
Issued at 300 PM CDT Mon Aug 12 2024

Upper ridge axis extended from New Mexico to northern Louisiana
early this afternoon with northern stream shortwaves over New York
and Illinois. At the surface, a frontal boundary was pretty close
to Interstate 10. Isolated to scattered convection had developed
this afternoon, with most of the storms nearly stationary. Early
morning soundings showed precipitable water values around 1.75
inches, but short range forecast guidance indicated values closer
to 1.9 inches are realistic this afternoon. Temperatures heated up
pretty quickly during the morning, but as cumulus and storms
developed around midday, that pretty much arrested any heating in
most areas with temperatures generally in the lower and middle 90s.
The exception was around Pascagoula/Trent Lott Airport (98F),
where the sea breeze hadn`t reached.

Expect most convection to dissipate close to 00z as we lose
surface heating. On Tuesday, ridging tries to build over the area
a bit, but forecast soundings also show moisture levels increasing
a bit, closer to 2 inches. This is likely to be reflected in
slightly higher surface dew points. That provides the potential
for heat index values to run a bit higher than today, which would
be just enough to justify Heat Advisories. The wild card, of
course, will be how quickly, and where, convection develops
tomorrow. Have gone ahead and issued an advisory for tomorrow,
knowing a few locations may not quite reach those levels before
convection arrives. Again tomorrow, convection should primarily
die out before sunset. Wind fields remain rather weak, so anything
that develops will probably rain itself out in place.

&&

.LONG TERM...
(Wednesday through Sunday night)
Issued at 300 PM CDT Mon Aug 12 2024

Overall, upper pattern doesn`t look to change much until Saturday
or Sunday, when northern stream troughing brings a bit more
northwesterly mid level flow to the area. The ECMWF is a bit
quicker in doing this than the GFS, but at this time range,
solutions could change or even flip between models, so will hold
onto NBM PoPs for the weekend. For the remainder of this workweek,
we will see the potential for isolated to scattered afternoon
convection each day with little day to day change in temperatures.
We`re likely to reach at least Heat Advisory criteria in most
areas for each of the next several days and will continue to
assess on a day to day basis.

&&

.AVIATION...
(00Z TAFS)
Issued at 541 PM CDT Mon Aug 12 2024

All terminals currently VFR. Will need to carry VCTS at KHUM and
VCSH at KHDC for the first hour or two, with radar showing cells
west of both terminals, but at the terminals. Expect all
convection over land to dissipate by about 02z, with VFR
overnight. Scattered cumulus likely to start developing around 17z
or so. Isolated to scattered TSRA expected on Tuesday afternoon
near KHUM/KBTR/KMSY/KHDC, especially in the vicinity of local
boundaries. Those terminals have somewhat better potential than
the remaining terminals, but threat is non-zero even there. Any
convection that develops isn`t likely to move much with very weak
low level wind fields, with propagation westward expected. Will
carry VCTS at this time for those western terminals, generally
after 18z, with dissipation prior to 00z Wednesday expected.

&&

.MARINE...
Issued at 300 PM CDT Mon Aug 12 2024

High pressure will remain the main controlling factor in the
marine weather. The weak pressure pattern will produce relatively
weak wind fields. However, thunderstorm development can be
expected during the late night and morning hours, which will have
the potential for lightning and wind gusts exceeding 30 knots.
This could produce locally higher seas in the vicinity of storms.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  74  96  75  97 /  10  20   0  20
BTR  79  99  79 100 /  10  30  10  20
ASD  77  98  77  99 /  10  30  10  20
MSY  79  97  80  97 /  10  40  10  30
GPT  78  96  78  97 /  10  30  10  20
PQL  77 100  77 101 /  10  30  10  20

&&

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

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

GM...None.
&&

$$

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