312
FXUS64 KLIX 200433
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1133 PM CDT Tue Aug 19 2025

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

.SHORT TERM...
(Today through Friday Night)
Issued at 1104 PM CDT Tue Aug 19 2025

One final day of hotter and drier than average conditions as
subsidence associated with a broad upper level high keeps PWATS
near or slightly lower than average. Temperatures will quickly
warm into the mid to upper 90s by the early afternoon hours and
heat index values to rise to between 105 and 110 degrees. Given
this, a heat advisory is in place for much of the forecast area
today. Only the immediate Louisiana coast will see heat index
values remain below 108 as temperatures are moderated by the
seabreeze. Convective activity will be isolated and will struggle
to persist longer than 30 minutes at a time due to the drier
airmass keeping mid- level lapse rates weak. As a result, PoP for
today is only in the 20 to 30 percent range. Additionally, the
convection should initiate more in the mid to late afternoon hours
due to a higher convective temperature in the low to mid 90s.

A shift to a cooler and wetter pattern will take hold tomorrow and
continue into Friday and Friday night. This is due to a trough
deepening over the eastern CONUS as Hurricane Erin moves up the
eastern seaboard. As the trough approaches on Thursday, winds will
turn more southerly and deeper tropical moisture will begin to
advect back into the region. PWATS will quickly respond by
climbing to around 2 inches for Thursday and Friday. These values
are between the 75th and 90th percentile for this time year. With
increasing moisture and instability in place, more numerous
showers and thunderstorms will develop and the convective
initiation will occur earlier in the day as convective
temperatures fall into the upper 80s. The addition of some weak
forcing aloft from the trough axis will also support more
sustained updrafts and a heavy rain potential both days. Storm
motion will be remain slow, so some localized street flooding
issues may arise with the strongest storms.

&&

.LONG TERM...
(Saturday through Tuesday night)
Issued at 1104 PM CDT Tue Aug 19 2025

The guidance has turned more bullish on a stronger trough diving
into the Midwestern states over the weekend. This stronger trough
will drive the front lingering over the area on Friday slowly
offshore Saturday and Sunday. Drier air will drift into the area
from the north with PWATS slowly falling back to the median or
around 1.7 inches on Saturday. There will be a gradient to the PoP
as the front will be along the coast and higher PWATS will still
be in that region. PoP values will range from 20 to 30 percent
north and west of Baton Rouge to 50 to 60 percent in coastal
Mississippi and coastal Louisiana on Saturday. By Sunday,
conditions will dry further as PWATS fall below the median and PoP
ranges from 10 to 20 percent in the north to around 40 percent on
the coast. As conditions dry out a bit, temperatures will warm a
few degrees into the low to mid 90s, but lowering dewpoints into
the upper 60s and lower 70s will help keep heat index values well
below heat advisory criteria this weekend.

The deepening trough will drive another cold front into the area
on Monday and Tuesday, and this front will stall either over the
region or just offshore based on the latest guidance as the parent
upper level low pulls further to the northeast. Moisture will be
limited with PWATS still running well below average, but enough
forcing along the frontal boundary will be in place to spark off
some widely scattered showers and storms. This is reflected by PoP
of 20 to 30 percent in the forecast both days. With a prevailing
northerly flow pattern in place, any storms will tend to develop
late in the day once the convective temperature in the low 90s is
achieved. Given the dry air in place aloft, there could be some
potential of stronger wind gusts in any deeper updrafts that
manage to form on Monday and Tuesday. Dewpoints will mix out into
the upper 60s and lower 70s each afternoon and temperatures will
rise into the low to mid 90s. The drier air will help keep heat
indices in check with values generally ranging from the upper 90s
to lower 100s. The biggest change will be somewhat cooler nights
as lows dip into the upper 60s over the northern third of the
forecast area. The decrease in humidity should be noticeable as a
drier heat develops over the region early next week.

.AVIATION...
(06Z TAFS)
Issued at 1104 PM CDT Tue Aug 19 2025

Overall, VFR conditions will prevail at all of the terminals
through the entire forecast period. However, there is a low chance
of seeing some convective impacts at BTR and HUM tomorrow
afternoon, mainly after 20z, and this is reflected with some
PROB30 wording at these terminals. Otherwise, the convective risk
is too low to include in the forecast at the remaining terminals.

&&

.MARINE...
Issued at 1104 PM CDT Tue Aug 19 2025

Benign conditions will persist through the weekend as winds stay
below 10 knots and seas remain at 2 feet or less. The only
concern will be locally higher winds and waves along with a few
waterspouts forming with any thunderstorm activity the fires up
across the waters. Thunderstorms will be most common in the early
to mid morning hours over the offshore waters and will be more
common in the afternoon hours in the tidal lakes due to the normal
seabreeze/landbreeze cycle each day.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  74  96  73  92 /  20  20  20  60
BTR  75  96  75  94 /  20  30  20  60
ASD  75  95  75  94 /  10  10  10  60
MSY  79  94  79  93 /  10  20  10  60
GPT  77  92  77  92 /  10  20  10  50
PQL  75  93  76  92 /  10  20  10  50

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory from 11 AM to 6 PM CDT Wednesday for LAZ034>037-
     039-046>048-057-058-060-071-076>087.

GM...None.
MS...Heat Advisory from 11 AM to 6 PM CDT Wednesday for MSZ068>071-
     077-083>088.

GM...None.
&&

$$

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