Baton Rouge, Louisiana Weather Forecast Discussion

057
FXUS64 KLIX 040511
AFDLIX
Area Forecast Discussion
National Weather Service New Orleans LA
1211 AM CDT Sat Oct 4 2025
...New SHORT TERM, LONG TERM, AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1207 AM CDT Sat Oct 4 2025
- Rain and storm chances slowly increase through the weekend.
   Highest rain chances will be on Sunday.
- Winds and seas will remain hazardous through the weekend with
   Small Craft Advisory conditions.
- Minor coastal flooding along east facing shores of southeast
   LA, including portions of the tidal lakes, and Hancock, MS
   county is expected this weekend.
&&
.SHORT TERM...
(Today through Sunday)
Issued at 1207 AM CDT Sat Oct 4 2025
While ridging dominated much of the country east of the Rockies on
Friday, there was a weak upper low centered over Mississippi, with a
circulation center off the southeast Louisiana coast. Weak
convection was wrapping cyclonically around the circulation off the
coast, with the northern edge from just south of Houma to Port
Sulphur. At the surface, the axis of high pressure extended from off
the New Jersey coast to the Carolinas, then westward along
Interstate 40. The evening LIX upper air sounding was slightly more
moist than normal for early October with a precipitable water value
of 1.52 inches (average 1.35), but the soundings to the north and
west were closer to the 25th percentile for those sites
(JAN/LCH/SHV).
The moisture profile does increase a little bit during the day
today, but not radically. The moisture does start surging northward
late tonight and Sunday, with precipitable water values near 2
inches across most of the area by mid to late morning Sunday, thanks
to 20 to 30 knot east-southeast winds at 925 and 850 mb. While last
night`s GFS was really the only one pointing at this magnitude,
there`s quite a bit more agreement in the model guidance from the
daytime hours on Friday. A precipitable water value of 2 inches
would be above the 90th percentile for early October.
Still looks like most or all precipitation today should primarily be
south of the Interstate 10 corridor, with the McComb and Baton Rouge
areas remaining dry. Won`t rule out a stripe of rain in excess of an
inch today, but at present it appears that should be well south of
New Orleans. The precipitation shield should gradually begin spread
northward tonight as the upper circulation gets pulled northward by
troughing moving out of the Rockies. Scattered to numerous showers
and a few thunderstorms will overspread the entire area on Sunday.
Any threat of heavy rain on Sunday should be limited to areas
generally east of Interstate 55, on the east side of the trough
axis, where 1 to 2 inches of rain looks possible, but a few
locations could see 2 to 4 inches of rain over the next 36 hours.
Considering it has been rather dry for the last 5 weeks or so, most
locations should be able to tolerate a couple inches of rain unless
it falls in a very short time over an urban area.
Not much change in the coastal flooding scenario anticipated with
minor coastal flooding of 1 to 2 feet above ground level in the
normally prone areas in Hancock County, eastern Orleans Parish, and
lower St. Bernard Parish during high tide cycles today and again on
Sunday. While water levels are running higher on Lake Pontchartrain
and Maurepas than forecast, no indications at this time that they
will reach levels that would cause issues. Current Coastal Flood
Advisory will remain in place through Sunday`s high tide cycle.
High temperatures never got out of the 80s across the area on
Friday, and those numbers look like a pretty good starting point for
today. With overcast conditions and afternoon precipitation, Sunday
should be cooler than today, with most or all of the area in the
upper 70s or lower 80s. Humidity levels will be higher, though, so
it won`t feel any cooler.
&&
.LONG TERM...
(Sunday night through Friday)
Issued at 1207 AM CDT Sat Oct 4 2025
The upper circulation is expected to be pulling north of the local
area by Monday morning. There will be some drying of the column,
especially in the mid levels, on Monday, but not enough to dry
things out completely. The heavy rain threat will have diminished,
but sunshine will likely remain very limited, with high temps
struggling to get out of the mid 80s, especially eastern half.
It appears that low level flow, 700 mb and below, will remain
easterly during much of the workweek, through at least Wednesday.
There are some indications that the East Coast trough pattern that
we`ve been in for much of the last couple months may re-establish by
the end of the week. Rain chances will diminish a bit each day, and
by Thursday or Friday, we may be looking at a dry forecast. Of
course, with less precipitation and cloud cover, that`s likely to
allow for warmer high temperatures, possibly nearing 90 in some
locations Wednesday. As we get deeper into October, with less
daylight, average high and low temperatures really start to show a
downward trend. By the end of next week, average highs are generally
in the lower 80s and overnight lows range from near 60 over
southwest Mississippi to the mid 60s in areas just south of Lake
Pontchartrain. The numbers that are in the current forecast for mid
and late week are about 5-7F above normal. All indications are that
beyond the next few days...warmer and drier than normal conditions
are expected for a good portion of October.
&&
.AVIATION...
(06Z TAFS)
Issued at 1207 AM CDT Sat Oct 4 2025
All terminals VFR at forecast issuance, except KHUM where MVFR
conditions have just begun. Convection associated with the weak
upper low just off the southeast Louisiana coast may edge a bit
northward later tonight, and more significantly impact KHUM toward
sunrise. However, any lightning this evening has generally been
limited to the offshore waters near lower Plaquemines Parish, and
have no plans to carry mention of TSRA in terminals overnight at
present other than at KHUM. MVFR ceilings and visibilities will
be possible with any precipitation that occurs tonight or
Saturday, with at least some threat of IFR conditions at KHUM
prior to sunrise. Will not carry precipitation in the
KBTR/KHDC/KMCB terminals through the period, as we do not expect
any significant precipitation to spread that far north.
Easterly winds of 15 to 25 knots will be possible at the coastal
terminals, mainly during the daytime hours.
&&
.MARINE...
Issued at 1207 AM CDT Sat Oct 4 2025
A broad area of low pressure over the central Gulf and a high
pressure system over the eastern seaboard will keep a persistent
easterly flow of 15 to 25 knots in place across all of the waters
through Sunday. A few gusts to gale force are possible, especially
in the far outer waters, but do not appear frequent enough or
widespread enough to justify a Gale Warning. These winds will also
have a pretty long fetch across the eastern Gulf waters, and this
will support higher seas of up to 10 feet in the open Gulf waters
due to a combination of wind waves and swell. Small craft advisories
are in effect through Sunday evening due to these hazardous
conditions. The high will start to become more dominant over the
waters on Monday and Tuesday, and this will allow the easterly winds
to relax a bit to between 10 and 15 knots. Seas will also decrease
to 2 to 4 feet as the winds relax. Increased easterly winds of 15 to
20 knots and higher seas may once again take hold beyond Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB  86  67  80  69 /   0  10  50  30
BTR  86  69  83  71 /  10  10  60  30
ASD  82  68  79  69 /  30  40  70  50
MSY  84  73  83  74 /  40  50  70  50
GPT  82  69  80  71 /  30  50  70  50
PQL  82  68  80  69 /  20  60  70  60
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Advisory until 6 PM CDT Sunday for LAZ069-070-076-
     078.
GM...Small Craft Advisory until 6 PM CDT Sunday for GMZ532-534-536-
     538-555-557-575-577.
Small Craft Advisory until 6 AM CDT Sunday for GMZ550-552-570-
     572.
MS...Coastal Flood Advisory until 6 PM CDT Sunday for MSZ086.
GM...Small Craft Advisory until 6 PM CDT Sunday for GMZ534-536-538-
     555-557-575-577.
Small Craft Advisory until 6 AM CDT Sunday for GMZ552-570-572.
&&
$$
SHORT TERM...RW
LONG TERM....RW
AVIATION...RW
MARINE...RW

NWS LIX Office Area Forecast Discussion