Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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350
FXUS64 KLIX 311755 AAA
AFDLIX

Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
1255 PM CDT Thu Jul 31 2025

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

...Corrected individual section headers to be reflective of
transmisison time...

.SHORT TERM...
(Tonight through Friday)
Issued at 1249 PM CDT Thu Jul 31 2025

Local area remains in a weakness between two upper ridges, so with
an absence of any large scale forcing, diurnally induced
instability will be the main driver of convection this afternoon
through this evening. Air mass is not as juicy as it was
yesterday, with this morning`s sounding indicating a precipitable
water (PW) of "only" 1.83 inches. Satellite estimates indicate
some recovery has occurred since then, with PW values around 2"
as of midday, though this is still about a quarter inch lower
than yesterday`s observations. Despite the lower moisture content,
we should still see isolated to widely scattered showers and
storms start to develop as we move into peak heating hours. No
substantial threat of severe weather, but as is typical in the
summer, a few pulse storms could produce damaging wind gusts if
they`re able to develop a robust enough updraft before collapsing.

Going into tomorrow, an upper level trough axis will move past
the Great Lakes region toward the northeastern CONUS. In response,
a weak frontal boundary will sink slowly southward toward the
local area. With the weak troughing aloft and the boundary
approaching from the north, expect to see an increase in
convective coverage tomorrow afternoon. Main threats from any
thunderstorms will be wind gusts of 30-40 mph, frequent lightning
and periods of locally heavy rainfall, as is typical in the
summer.

Ahead of convective development tomorrow, heat index values could
jump up quickly to the 108-110 degree range across portions of
the area, but this is highly conditional on exact timing of
convection and specific temps/dewpoints across the region. Any
heat advisory conditions appear to be localized and temporary in
nature at this time as well. Given current low confidence in
reaching criteria, will hold off on issuing a heat advisory for
tomorrow, though one may be needed with the next forecast update.


&&

.LONG TERM...
(Saturday through Wednesday)
Issued at 1249 PM CDT Thu Jul 31 2025

Main question for the weekend and into next week continues to be
centered on exactly where the previously mentioned frontal
boundary will eventually stall and wash out. GFS and its ensemble
members continue to be a bit more bullish with a more significant
airmass modification behind the front when compared to the Euro
and its ensemble members. This explains the unseasonably low POPs
that continue to be advertised in the MEX guidance when compared
to other available guidance.

Given the time of year, think the GFS is a bit too aggressive
bringing the significantly drier air all the way to the coast and
even across the northern Gulf following the front. Thus, will
continue to carry higher POPs as advertised within the NBM, given
the stalled boundary should also serve as a focus for convection
each day through the extended as it gradually dissipates.

If, however, the airmass behind the front is, indeed,
substantially drier than currently forecast, downward adjustments
to the POP forecast through the weekend and start of the next work
week would be needed.

&&

.AVIATION...
(18Z TAFS)
Issued at 1249 PM CDT Thu Jul 31 2025

VFR conditions will prevail outside of any temporary convective
impacts. With only isolated to widely scattered showers and
storms forecast this afternoon, will keep any mention of
convection limited to MVFR conditions within PROB30 groups. Any
more significant short-term restrictions this afternoon will need
to be handled by short term amendments. Convective coverage will
increase Friday, with showers and storms developing through the
late morning hours and spreading inland through the afternoon.
With uncertainties in exact timing and placement, will carry
PROB30 groups for the time being mainly at the southern terminals
starting between 13z and 16z.

&&

.MARINE...
Issued at 1249 PM CDT Thu Jul 31 2025

Outside of convective impacts, conditions will remain benign
across the coastal waters. Expect to see an increase in shower and
thunderstorm activity beginning Friday, with a fairly typical
diurnal ebb and flow. A few strong storms will be possible each
day, and could result in gusty winds, waterspouts, and locally
higher waves/seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  74  94  73  91 /  30  70  30  50
BTR  76  94  76  93 /  30  70  40  60
ASD  76  94  74  93 /  30  70  50  60
MSY  80  95  79  94 /  20  80  40  70
GPT  78  94  76  93 /  30  70  50  60
PQL  76  94  75  93 /  30  70  50  70

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory until 7 PM CDT this evening for LAZ034>037-039-
     046>048-056>060-064-065-070-071-076>090.

GM...None.
MS...Heat Advisory until 7 PM CDT this evening for MSZ068>071-077-
     083>088.

GM...None.

&&

$$

SHORT TERM...DM
LONG TERM....DM
AVIATION...DM
MARINE...DM