183
FXUS64 KLIX 081718
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1218 PM CDT Tue Jul 8 2025

...New AVIATION, MARINE...

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 1142 PM CDT Mon Jul 7 2025

Rain-saturated southwest Mississippi is observing locally
enhanced low-level RH values from late afternoon storms which in
combination with clear skies and near-calm winds will result in
light patchy fog development across areas near water bodies and
low-lying areas again this morning around sunrise. McComb is 72/71
from the rain-cooled air with calm winds, just like yesterday,
which lends confidence we`ll see patchy fog conditions, but
significant impacts from dense fog are not anticipated.

The weak upper trough has continued to back away and weaken over the
northwest Gulf allowing rising mid-level heights and high pressure
to nose itself farther west over the northern Gulf coast today.
Latest 00z guidance continues to suggest less storm coverage
compared to prior days and NBM guidance has fallen in line with this
idea finally. That said, PoPs are still in the 40-60% range,
especially along and west of the I-55 corridor where moisture and
less suppressive atmospheric conditions will still be present.
Confidence is higher for areas along the immediate coast of SE St.
Tammany and coastal MS to remain dry once again today as the lake
and seabreeze push inland before showers and storms attempt to
develop and this is reflected by 20-40% PoPs, which still may be a
tad generous.

Our attention then turns to a weak shortwave trough currently
situated over North Dakota which will dip down around the eastern
periphery of the rebuilding SW CONUS ridge today. This weak
shortwave will arrive to the Mid Mississippi River Valley by
Wednesday, slow down as it gets stuck in between the ridges on
either side of it, and begin to lose its coherence. As it does so.
This will begin the gradual trend back up in PoPs each afternoon
starting Wednesday afternoon and continuing into the latter half of
the week.

&&

.LONG TERM...
(Thursday through Monday night)
Issued at 1142 PM CDT Mon Jul 7 2025

Deep moisture will increase across the area with PWAT values
forecast to be near or just above 2 inches across most of the area
in conjunction with the approaching weak shortwave trough. This
should lead to a further increase in convective coverage with storms
becoming more numerous to widespread Thursday and Friday. The
increase in moisture will also lead to more efficient rainfall
within the storms that develop. While widespread heavy rain is not
forecast, individual storms will be capable of producing high
rainfall rates exceeding 3 inches per hour that can cause quick
accumulations and overwhelm street drainage systems.

The more zonal orientation of this weak shortwave portrayed in the
global model guidance on Thursday just to the north of the CWA does
leave room for some uncertainty in exactly how widespread convection
will be despite NBM guidance advertising 80% PoPs almost areawide,
and it`s possible we see some spatial and magnitude adjustments as
this comes into view of CAM guidance. The shortwave troughing will
linger into Friday in the weakness between ridges so afternoon PoPs
will remain elevated higher than climatological norms.

By the weekend, it`s less clear whether we`ll see this troughing
linger and continue to enhance afternoon PoPs or if the ridge will
nose back in enough to allow temperatures to get closer to the mid
to upper 90s. Heat indices could push closer to the 105-110F range
if so. Regardless, the muscle memory of this pattern continues to
support persistence forecasts of near or slightly above normal
temperatures with elevated chances for afternoon storms each day,
and that will continue until we see an appreciable shift to the
longwave weather pattern at a time TBD.

&&

.AVIATION...
(18Z TAFS)
Issued at 1212 PM CDT Tue Jul 8 2025

All terminals generally under VFR conditions through the period.
However, TSRA occurring through the evening until convective
activity dies out, could result in reductions to MVFR due to
lowered VIS and CIG.

&&

.MARINE...
Issued at 1212 PM CDT Tue Jul 8 2025

Marine conditions will be benign through the period outside of any
localized impacts from convection. Winds will remain between 5 to 15
knots out of the south to southwest in an onshore direction through
the work week. A fairly typical summertime convective pattern is
expected with showers and storms developing during the late night,
peaking during the morning hours, and diminishing through the
afternoon and evening. Storm coverage over the waters will
increase during the morning hours each morning starting Wednesday
into the weekend with storms most widespread on Thursday.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  71  92  72  90 /  20  60  20  70
BTR  74  92  75  92 /  20  70  20  80
ASD  74  92  74  92 /  10  60  20  80
MSY  77  94  78  93 /  10  60  20  80
GPT  75  92  76  92 /  20  50  30  70
PQL  73  92  73  92 /  20  50  40  70

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&

$$

SHORT TERM...TJS
LONG TERM....TJS
AVIATION...DS
MARINE...DS