246
FXUS64 KLIX 150258
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
958 PM CDT Wed Aug 14 2024

...New UPDATE...

.UPDATE...
Issued at 954 PM CDT Wed Aug 14 2024

Still a couple isolated thunderstorms southwest of New Orleans,
but even these should die out in the next hour or so. Expect the
remainder of the night to be dry in most areas. Another hot day on
tap Thursday, with scattered thunderstorms developing around mid-
afternoon to hopefully provide some relief. Have updated ZFP to
lower PoPs overnight and to better handle temperature/wind trends
for the rest of the night.

&&

.SHORT TERM...
(This evening through Thursday night)
Issued at 303 PM CDT Wed Aug 14 2024

Northerly mid-level flow and dry air around 500mb have kept
convection at bay for most of the day today. In fact, efficient
dry air mixing has been taking place today throughout much of the
afternoon, leading to the soaring temperatures near triple digits.
So, although the actual temps continue to climb this afternoon,
the dry air mixing has kept the dew points on RH lower. It`s
definitely still hot, but this keeps us under the excessive heat
warning threshold. We are just now seeing convective development
across the area as we reach the convective temperature. The
aforementioned mid-level dry air has lead to some high DCAPE
across the area in the 1000-1400 j/kg range. Therefore, any strong
storm will be capable of producing strong to severe downdraft
winds. Low-end hail cannot be ruled out, but the the freezing
level being around 16 kft, hail seems unlikely. In fact, the high
freezing level would promote hail melting with the stronger cores,
and the melting hail will just create more downward momentum for
downdrafts, further supporting the isolated damaging wind risk.
Any convection that does form should dissipate shortly after
sunset around 9 or 10pm.

The mid-level ridge is expected to continue to slide westward
across the ArkLaTex tomorrow, putting us into a more northeast
flow regime. With it, much of the dry air aloft is expected to
move westward as well. This opens up the door for more convective
development with less suppression from the departing ridge and
higher moisture. For context, PW will go from 1.9 inch today to
over 2.2 inches tomorrow. Thus, PoPs were bumped up from NBM to
account for this. High-res models depict convective development
across SE Mississippi tomorrow before propagating southwestward
with the mean mid-level flow. Isolated damaging winds is the main
threat again as DCAPE seems to remain elevated from 800-900 j/kg
due to dry air below 850mb. Development seems likely around noon
or 1pm tomorrow as that area reaches the convective temperature,
and the cluster of storms should exit the area or dissipate
shortly after sunset around 9 or 10pm. Outside of convection,
there is expected to be a brief window where the temperatures get
hot enough for a heat advisory before convection cools off the
area during the afternoon and evening. However, a small change in
timing and coverage could prevent it from getting that hot.

Above average moisture looks to hang around on Friday, so
convective coverage is expected to be similar to Thursday. Much of
that development looks to be dictated by seabreeze and lakebreeze
boundaries. DCAPE seems to be a little lower (~700 j/kg) on Friday
as the lower-level moisten up, but isolated strong to severe wind
gusts cannot be ruled outwith any strong storm. Similar to
tomorrow, how hot we get depends a lot on convective timing and
coverage. This will need to be monitored for an additional heat
advisory for Friday.

&&

.LONG TERM...
(Friday through Tuesday night)
Issued at 303 PM CDT Wed Aug 14 2024

Saturday has some questions about the forecast right now. The 00Z
globals, mainly the Euro, was showing an MCS make it`s way down into
the region but the 12z has backed off on this idea some. This comes
as a frontal boundary will approach the area and eventually stall
out somewhere. Where exactly is the question. Regardless, this
boundary and associated outflows with the already increased moisture
will cause PoPs to be higher.

Heading into the late weekend and early next week, we are looking to
be back on the drier side again. While the dewpoints drop back down
some, the temperatures aren`t really affected and may even go back
up a tick. Knowing this, we will likely still be very close to or at
Heat Advisory criteria again after likely having a small break over
the weekend due to the increased rain chances.

&&

.AVIATION...
(00Z TAFS)
Issued at 624 PM CDT Wed Aug 14 2024

Robust convection continuing at forecast issuance time, and will
need to carry TEMPO TSRA for the first couple hours of the
forecast at KGPT/KASD/KMCB/KBTR. Have seen quite a few wind gusts
to 35KT with convection, along with IFR visibilities. Expect
convection to wind down prior to 03z, with VFR the remainder of
the night. Expect convection to refire during the afternoon on
Thursday, with areal coverage at least as good as today. Most
convection allowing models don`t develop much prior to 18z
tomorrow. Based on the timing of convection the last few days,
will carry TEMPO TSRA at multiple terminals during the late
afternoon tomorrow.

&&

.MARINE...
Issued at 303 PM CDT Wed Aug 14 2024

With high pressure meandering around at the surface, we`ll see
variable winds over the next couple days but they will remain light.
WIth light winds, we also see pretty low seas but thunderstorms over
the waters may cause higher winds and seas at times. Thunderstorm
coverage will increase tomorrow and over the next couple days.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  76  96  75  95 /  40  70  20  60
BTR  80  99  79  98 /  20  60  30  60
ASD  77  98  76  96 /  30  70  30  70
MSY  80  98  80  95 /  10  70  30  70
GPT  77  96  78  93 /  50  70  30  70
PQL  75 100  78  96 /  50  70  30  70

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory from 10 AM to 6 PM CDT Thursday for LAZ034>037-039-
     046>048-056>060-064>071-076>090.

GM...None.
MS...Heat Advisory from 10 AM to 6 PM CDT Thursday for MSZ068>071-077-
     083>088.

GM...None.
&&

$$

SHORT TERM...JZ
LONG TERM....HL
AVIATION/UPDATE...RW
MARINE...HL