Bay St. Louis, Mississippi 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

428
FXUS64 KLIX 121627
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1127 AM CDT Tue Aug 12 2025

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

.SHORT TERM...
(This afternoon through Wednesday)
Issued at 1049 AM CDT Tue Aug 12 2025

Plenty to discuss as we approach the noon hour late this morning.
Starting out with a broad overview/synopsis, the northern Gulf
resides in a general weakness separated between a 594dm ridge
offshore the Florida Atlantic coastline and broad/weak troughing
over the central US. Between both features, we have a weak impulse
parked over our outer 20-60nm Gulf waters as indicated by recent
obs/RAP mesoanalysis data providing a pretty impressive convective
blowup over marine areas this morning. Even so, KHDC shows subtle
spinning aloft with this impulse. The associated dynamic ascent
and marine instability has led to numerous/widespread convective
coverage over Gulf marine zones. Waterspout parameters, including
0-0.5/0-1km bulk shear, moisture profile and low-level sfc
vorticity remains strongly favorable for waterspout development,
which could occur at any point today with storms anchored to
boundaries. Meanwhile over land areas, similar to the past few
days the challenge for us becomes actually... in the upper-levels.
H2-H3 flow remains generally out of the south, helping to cause
Anvil canopy blowoff north. Knowing all of this, now we venture
into the short-term CAMs to see how they are initializing. The
extended 12Z HRRR is coming in handling the ongoing convective
blowup, with eventual turnover for land area today. As always,
it`s not that simple. Areas that see more sunshine/surface heating
today will quickly hit Tc allowing in airmass pop-up storms.
However, areas that see more upper-level clouds will slow surface
heating keeping a lid on diurnal convection. Pulling everything
together and looking over the 13Z NBM, without a doubt given the
recent accuracy of the HRRR initializing well, and the dynamic
ascent support for coastal/marine areas and diurnal support for Ci
later this afternoon/evening for land areas, coverage will be
high today. PoPs in the 50`s for NW areas to 80`s for coastal
areas looks reasonable given the aformentioned meteorological
analysis. No reason to detour from this thinking. Coastal areas
could see a passing shower/storm generally at any point today,
with land areas more later in the afternoon and evening. Thinking
also we`ll see marine convection subside going into the early
afternoon with the typical switchover. Additional hazards to
monitor today will be localized flash flooding. 850mb transport
vectors NW of the marine disturbance is generally oriented from
the NE, while corfidi upwind vectors remain oriented out of the
SW. This will support storms generally on NE/SW oriented
boundaries with some leading to backwards propagation. This,
supported by overall weak average storm motion and high PW will
lead to intense rain rates, quickly causing localized flooding.
Will keep a close eye on this today. Be aware given the wide range
of rainfall totals, it`s difficult and not scientifically sound
to provide accurate model-blended QPF rainfall totals, as actual
amounts will vary significantly in this regime. WPC maintains a
SLGT risk across the Southshore to coastal MS, closest in the
proximity to these boundaries and source of dynamic ascent wich
appears probable. Will keep a close eye on it. Otherwise,
temperatures look good reflecting the PoP/cloud cover situation
as earlier discussed, yielding lower afternoon highs along the MS
coast (mid 80s) vs lower 90`s for western areas where there will
be more sunshine.

Overnight, same story as we`ll see turnover back to marine waters
with widespread convection expected yet again in the proximity of
the disturbance aloft. Waterspouts, locally strong wind gusts
>34kts and locally enhanced wave/seas will remain the main risks
with these storms. PoP coverage continues to remain enhanced
tomorrow given the latest guidance with widespread 60-70% PoPs.
Timing will vary similar to today, but overall not expecting any
deviation in the forecast through Wednesday but will conitnue to
monitor short-term trends and adjust where/if necessary. KLG

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 1049 AM CDT Tue Aug 12 2025

As we progress into late-week, the disturbance weakens and departs
the area and is steadily replaced with building 594dm ridging over
FL into the northern Gulf. What we`ll see is a transition into
more typical afternoon coverage (30-50%) and greater in the
afternoon with daily coastal/marine convection. You know what that
means, PoPs trend down, temperatures trend up. Projected max
apparent T`s are looking to start building upwards Friday into
the weekend, reaching Heat Advisory criteria yet again (generally
106-110F range). Something to keep in mind as we approach the
upcoming weekend for those with outdoor plans/activities. KLG

&&

.AVIATION...
(18Z TAFS)
Issued at 1049 AM CDT Tue Aug 12 2025

For this afternoon, radar trends continue to illustrate greater
coverage of SHRA/TSRA across/nearby coastal terminals. However,
confidence remains higher that we`ll see scattered activity build
north for inland terminals through the afternoon/evening. Main
impacts will be locally erratic gusty downdraft winds in excess of
20-30 knots and reduced visibility and CIGs from heavy rain
causing periodic lower flight categories. Outside of TSRA/SHRA
activity, expect VFR with light sfc winds. Expecting to see a lull
in activity later this evening, with VFR prevailing but could see
some localized areas of lower CIGs for coastal terminals. KLG

&&

.MARINE...
Issued at 1049 AM CDT Tue Aug 12 2025

Main focus in the short-term will be ongoing shower/storm coverage
over marine areas through early afternoon. Wind/wind gusts of 15-
20kts can be expected generally for marine zones offshore the
mouth of the MS to 60nm through 00Z, with exercise caution
headlines in effect until this activity diminishes. Expecting to
see a lull in activity later this afternoon/evening into early
tonight before another round of showers/storms are expected to
develop later tonight into early Wednesday. Main risks with any
one stronger or severe storm will be locally strong wind gusts
greater than 34 knots, waterspouts and locally enhanced/waves
seas. This pattern stays in place through the week, but coverage
backs down some going into later this week and weekend with
generally light surface winds and calm waves/seas outside of
thunderstorm activity. KLG

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  90  73  89  73 /  70  30  70  20
BTR  92  75  90  75 /  70  30  60  10
ASD  88  74  89  74 /  70  40  70  10
MSY  91  77  90  78 /  70  30  70  10
GPT  87  75  89  75 /  80  50  70  10
PQL  86  74  89  75 /  80  50  70  20

&&

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

$$

SHORT TERM...KLG
LONG TERM....KLG
AVIATION...KLG
MARINE...KLG