Bay St. Louis, Mississippi 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

101
FXUS64 KLIX 060512
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1212 AM CDT Sat Sep 6 2025

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

.SHORT TERM...
(Today through Sunday)
Issued at 1210 AM CDT Sat Sep 6 2025

Similar to this time last night, upper ridging from southern
California to British Columbia with the main upper low along the
Quebec-Ontario border. A strong shortwave was rotating around the
upper low and was over Iowa, with another over North Dakota. At the
surface, high pressure was centered over Kansas. A cold front
extended from near Pittsburgh, to Memphis to the Dallas-Fort Worth
area, to central New Mexico. Isolated showers across the area Friday
afternoon dissipated around sunset. Weak onshore flow had increased
low level moisture a bit with mid-evening dew points between 70 and
75 across the area, but north of the cold front, north of Interstate
40, dew points were dropping to around 50 degrees. The airmass
remained comparatively dry across the local region with upper air
soundings from the 00z release around 1.5 inches. That`s between the
25th and 50th percentile for the first week of September.

The shortwave over Iowa Friday evening will lift northeastward into
the Canadian Maritime Provinces by Sunday morning, as the North
Dakota shortwave follows quickly on its heels through the southern
Great Lakes into Quebec by Sunday evening. A third shortwave will
already be over Ohio by that point.

What does this mean for the local area? It means that not only will
the cold front move through the local area today, but that it will
be well out into the Gulf by the end of the weekend. As we saw
Friday afternoon, there is enough moisture available to produce at
least a few isolated showers across the area, primarily on lake and
sea breeze boundaries, but deeper moisture, enough to produce
thunderstorms, is for the most part lacking. Precipitable water
values remain between 1.5 and 1.7 inches for much of the weekend.
Anything much more than 20-30 PoPs isn`t justified for either today
or Sunday at this point, and on Sunday, that`s probably the lower
portions of the Louisiana coastal parishes at best.

Unlikely to see much impact to high temperatures today, with highs
again in the lower 90s. Sunday will see some cooling across at least
northwest portions of the area, but northerly wind flow, especially
immediately behind a cold front, could still produce highs in the
lower 90s from about the Pearl River Basin eastward.

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 1205 AM CDT Sat Sep 6 2025

Some weakening of the upper trough across the eastern half of the
country is apparent as we go toward midweek, with some ridging
attempting to build into the Mississippi River Valley by the end of
the week. Medium range models are struggling on a consensus solution
beyond about Tuesday or Wednesday, but at this point, it doesn`t
appear that the solutions they are depicting will have significant
impacts on the local weather through the end of the workweek, with.
surface high pressure forecast to be parked over the Great Lakes.

Another shortwave moving through the base of the trough could
produce isolated or scattered showers somewhere around Tuesday
afternoon or possibly Wednesday, but rain amounts, if any occurs at
all, will be light for most of the area.

The most noticeable weather will occur Sunday into about Tuesday.
With multiple pushes of cooler and drier air, especially for early
September, our area will see much more comfortable humidities, and
cooler overnight lows, with much of the area other than downwind of
Lake Pontchartrain dropping well into the 60s Monday and Tuesday
mornings. Similar to the previous package, lows and dew points were
nudged downward slightly Monday through Tuesday morning to account
for recent NBM biases and the unseasonable airmass. Dew points in
this scenario could mix out even lower than what is being indicated
Monday afternoon before moderating during the day on Tuesday. For
the second half of the workweek, temperatures will return to near or
slightly above normal with highs in the lower 90s and lows around 70
being common.

&&

.AVIATION...
(06Z TAFS)
Issued at 1205 AM CDT Sat Sep 6 2025

Mainly VFR conditions through the forecast period with high clouds
overspreading the area. May be brief restrictions (MVFR) at KMCB
around sunrise, and perhaps KBTR, but those will mix out pretty
quickly. During the daytime hours, will only mention VCSH at KMCB.

&&

.MARINE...
Issued at 1210 AM CDT Sat Sep 6 2025

Winds should be rather variable today and seas will run around 1
foot. Conditions are likely to become somewhat rougher as cooler air
reaches the open waters by Sunday morning. Later forecasts will
likely need to introduce Small Craft Exercise Caution headlines for
at least portions of the waters for the daytime hours on Sunday,
with a wider distribution of headlines Sunday night, when Small
Craft Advisories are likely to be needed into Monday afternoon
before conditions improve somewhat.  Seas will respond to these
stronger winds and potentially increase into the 3 to 5 foot range
Sunday night or Monday, with these wind and wave conditions
potentially continuing into Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  88  67  85  62 /  30  10  10   0
BTR  91  71  88  66 /  20  10  10  10
ASD  90  69  89  64 /  10  10  10   0
MSY  92  76  90  72 /  20  10  10  10
GPT  90  71  91  67 /  10  10   0   0
PQL  92  70  91  65 /  10  10   0   0

&&

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

$$

SHORT TERM...RW
LONG TERM....RW
AVIATION...RW
MARINE...RW