Marine Weather and Tide Forecast for Mandeville, LA

SHORT TERM
(Now through Monday)
Issued at 1138 PM CDT Thu Apr 9 2026

Very normal spring-like cycle is ongoing. This shows a general pattern of moderate to strong easterly to SE winds around a developing Bermuda High in the Atlantic. Tide levels will remain on the high side but as we move into a neap tide cycle, these tides will lower during high tide times. Water levels are not very high at the moment but are continually rising to meet an annual level of +1ft that what we see at the lowest tides around December and January. This extra foot of water is what tends to bring our area and other areas of the gulf coast into coastal flood levels during spring tide cycles especially when meteorological forcing helps. Any rainfall through Monday would need to come from a weakness that will follow along and west of the 1021-1022mb isobar lines. The 1022mb line will be near or over the Atchafalaya today and this is where the highest chances of rain will be for our area. Farther east of this is too dry above the sfc to get much shower activity. This won't be the variety of rain to make headlines. This very weak troughing will move slightly farther west for the weekend and that is all it will take to bring most of the area to less than 10% precip numbers.

LONG TERM
(Monday night through Thursday night)
Issued at 1138 PM CDT Thu Apr 9 2026

An upper ridge is expected to be controlling the weather over the Gulf Monday night. Shortwaves moving out of the southern Rockies toward the Great Lakes will gradually erode western portions of the ridge, re-orienting it northeast to southwest from the Georgia coast to the Bay of Campeche by Thursday. The surface pressure pattern really isn't expected to change much during this period, though, with the high extending from Bermuda westward across the northern Gulf Coast into southeast Louisiana and southern Mississippi.

Similar to what we were seeing in guidance 24 hours ago, the surface pressure pattern will generally keep the winds coming out of the east or southeast through the period. For most of the period, forecast soundings show only limited moisture above 850 mb.
Precipitable water values remain near or below 1 inch for much of that time, with 1 inch being pretty much right at the daily mean.
Even the wettest forecast soundings only briefly reach the 75th percentile (1.2-1.3 inches).

This pattern should keep most of the area dry through the period.
Although one or two showers could occur on pretty much any day, the only day that might have a mention in the grids is next Thursday, and that is only over the extreme northwest portion of the area well northwest of a McComb to Baton Rouge line, and only a slight chance there. Rainfall amounts during the long term period are expected to be less than one-tenth of an inch for most areas, with a totally dry period a more likely solution. Well above normal temperatures (5-10F above) will continue with highs mainly in the 80s, although the immediate coast might fall a degree or two short depending on timing of the daily sea breeze. Not out of the question that somewhere in our CWA a location reaches 90 degrees next week, which would be early, but not record-breaking unless it is McComb. The average first 90 degree day at our climate sites occurs in mid-May.
Overnight lows will mainly be in the 60s. (RW)

AVIATION
(06Z TAFS)
Issued at 1138 PM CDT Thu Apr 9 2026

VFR conditions are expected through much of this taf cycle. There will be better chances for cigs over the eastern half of the area today and tonight but these should remain at the lower end of VFR. A chance of -RA will also accompany these cigs to the west today, but will not be high enough at any terminal to show in this taf set. Tonight, vis could drop a bit more than it has been lately, but should remain in MVFR or higher for all terminals.

MARINE
Issued at 1138 PM CDT Thu Apr 9 2026

Strong high pressure over the northwest Atlantic continues to produce a moderate to strong easterly fetch over the northern Gulf.
Hazardous marine conditions are ongoing with Small Craft Advisories in effect through mid morning today. Conditions will only modestly improve going into the weekend . There will likely be at least cautionary headlines needed right into the start of the new workweek as east and southeast winds remain at 15 to 20 knots at times.

LIX WATCHES/WARNINGS/ADVISORIES
LA...None.
GM...Small Craft Advisory until 8 AM CDT Friday for GMZ550-552-555- 570-572-575-577.

MS...None.
GM...Small Craft Advisory until 8 AM CDT Friday for GMZ552-555-570- 572-575-577.