Marine Weather and Tide Forecast for Slidell, LA

SHORT TERM
(This evening through Sunday night)
Issued at 144 PM CST Sat Jan 17 2026

The entire CONUS except for the west coast of the US is under a deep and broad upper level trough. Am embedded shortwave within the main trough is currently moving south across the central US. Surface dewpoints are steadily dropping across the CWA as post frontal continental airmass filters into the region. Southwesterly flow aloft ahead of the approaching shortwave trough axis has been ushering in moisture in the mid/upper level....evident by the mostly virga currently seen on radar.

The trough axis will sharpen and pivot from very positive to almost neutral across the lower Mississippi Valley tonight into Sunday.
That sharpening causes flow around the base of the trough to accelerate. That acceleration then increases positive vorticity advection downstream on the east/SE side of the trough axis, which at this point is over southern LA/MS/AL. Model solutions continue to show the real sharpening until right as or after the trough axis passes across the CWA Think this is a key reason why forced ascent from the PVA doesn't really get frontogenesis going along the LA coast but rather moreso into coastal MS/AL and points east. So that mid/level jet aloft is slightly weaker which can delay the timing of moisture surge on the southeast side of the trough. This likely explains the variations placement/track of southwest to northeast rain shield during the Sunday morning hours. Saturating the column in the -10 to -20 dendritic zone is so important for development of snow flakes. While model soundings do show this in southeastern portion of the CWA, wetbulb down to the surface before dry air moves in from the north will be a challenge. You see that in the Baton Rouge sounding where just as the mid levels saturate, dry air punches in. Farther south near the coasts of LA and MS, there's a little more time for this to occur and hence why CAMs and Global models show precip there.

Taking timing of all that into consideration, the most likely scenario is swath of showers, maybe with small pockets of a mix of rain/sleet or rain/wet snow, moves across southeast LA south of the Lake around midnight. Within a few hours its all over there and maybe some snow flurries on the back end. Rain shield steadily moving east, the MS Coast could have a little more mixture of sleet/snow with rain for a couple hours right before 12z.

Confidence remains remains similar to previous forecast in location and overall low probability of any frozen precip and if it does happen, more likely tail end of the event locally which would be the MS coastal counties. Regardless, if any rain and snow/sleet mixture develops, antecedent ground temps should keep anything from sticking on roadways with only low potential on metal or grassy areas. Then, by midday Sunday, temps are already well into the 40s. Cold by climate standards but warm in terms of frozen precip potential.



LONG TERM
(Monday through Friday night)
Issued at 144 PM CST Sat Jan 17 2026

The remainder of the forecast period will be characterized by below normal temps but no rain expected until Wednesday night or Thursday. Strong CAA will keep lows in the upper 20s to mid 30s through Tuesday morning and near normal temps don't return until Wednesday.

AVIATION
(00Z TAFS)
Issued at 529 PM CST Sat Jan 17 2026

VFR conditions at all terminals at forecast issuance. There's a small potential for MVFR conditions at KGPT or KHUM in precipitation overnight. There's also a low end potential (30 percent) of -SN or PL at KGPT as the coldest air arrives well after 06z. All terminals should be SKC shortly after 12z Sunday, if not sooner.

MARINE
Issued at 144 PM CST Sat Jan 17 2026

A cold front is currently moving south across the local area. Its not a particularly strong front but borderline Small Craft Advisory conditions can be expected through Sunday morning. A reinforcing backdoor cold front moves into the Gulf Monday night. Winds may bump back up to exercise caution category but not looking like SCY at the moment. A short-term period of return flow does develop mid week as post front ridge situated north of the region slides east before the next cold front comes through late in the week.



PRELIMINARY POINT TEMPS/POPS
MCB 26 46 28 55 / 0 0 0 0 BTR 28 49 30 59 / 0 0 0 0 ASD 29 50 29 59 / 20 0 0 0 MSY 36 51 35 59 / 20 0 0 0 GPT 33 49 31 57 / 30 0 0 0 PQL 30 50 27 58 / 40 0 0 0

LIX WATCHES/WARNINGS/ADVISORIES
LA...None.
GM...Small Craft Advisory until noon CST Sunday for GMZ530-532-534- 536-538-555-557-575-577.

Small Craft Advisory until noon CST Sunday for GMZ550-552-570- 572.

MS...None.
GM...Small Craft Advisory until noon CST Sunday for GMZ532-534-536- 538-555-557-575-577.

Small Craft Advisory until noon CST Sunday for GMZ552-570-572.