Marine Weather and Tide Forecast for Slidell, LA

SHORT TERM
(Now through Wednesday)
Issued at 1049 AM CDT Tue Apr 21 2026

Tuesday will be mostly dry overall as weak ridging builds in over the area. Conditions will remain cooler and drier on the backside of the front today. Onshore flow has returned, which will advect humidities and warmer temperatures again. Highs Tuesday and Wednesday will be in the upper 70s and lows in the mid 50s to low 60s.

Wednesday into Thursday, an upper level shortwave approaches the area, especially near the Atchafalaya Basin and areas west of I-55.
There is very little forcing with this system, looking at the models. As a result, very little appreciable rain is expected with low PoPs (20-30%) for the Atchafalaya Basin and coastal Louisiana primarily due to isolated to scattered showers with some lighting possible. These rain chances have been trending drier, so wouldn't be surprised to see less rainfall than expected. MSW

LONG TERM
(Wednesday night through Monday)
Issued at 1049 AM CDT Tue Apr 21 2026

Weak ridging builds back over the area Thursday, followed by zonal flow Friday through Saturday. Looking at the models, conditions will be mostly dry these days as a result. An isolated to scattered shower or two is possible Friday afternoon as zonal flow comes into play combined with the high moisture availability, but these storms would not have a ton of appreciable rainfall. They will have the potential for some lightning, at least Onshore southerly flow will help to advect warmer and more humid air into the region. As a result, temperatures will be warmer as the week progresses. Highs are forecast in the low to mid 80s, especially later in the week. Lows are forecast in the mid to upper 60s.

Saturday into Monday, a couple of weak upper level impulse will move through the area, but there are still a lot of model uncertainties in this system. Initially, this systems look fairly weak overall with low rainfall amounts. The highest rainfall totals will be concentrated east of I-55, currently. But a lot of things can change in the next week, so we will keep monitoring closely. Another system looks to be moving through the area midweek next week as well, so we will also be monitoring that closely as we get toward the weekend.
MSW

AVIATION
(18Z TAFS)
Issued at 1049 AM CDT Tue Apr 21 2026

VFR conditions prevail at all area airports and will persist through the forecast period. Wind shifts greater than 30 degrees will be expected at all area airports. MSW

MARINE
Issued at 1049 AM CDT Tue Apr 21 2026

As high pressure shifts east of the waters, winds will gradually become southeasterly and then southerly over the next day or two. There will be little change in the surface pressure pattern for the next 3 or 4 days. A cold front will approach the area over the weekend, with some uncertainty whether it reaches the local waters.

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