Marine Weather and Tide Forecast for Mandeville, LA

SHORT TERM
(Now through Friday)
Issued at 104 AM CDT Tue Aug 4 2026

An upper level low is currently sitting above northern Georgia this morning keeping heights a bit on the low side even down here.
Today will be somewhat like yesterday with continued dry air and a very low chance of a shower or two right along coastal areas. With the surface northerly flow continuing temperatures will still be on the warm side, but like the last day or so despite hot it will be a bit more comfortable with the dry air and afternoon mixing taking place.

Going into late Wednesday and Thursday a kicker will grab the ULL, open it up and move it downstream allowing for heights to gradually increase. As the surface the flow begins to transition to a more onshore flow ushering in more moisture as well as increasing the chances of scattered convection during the afternoon hours. Temperatures do not look to change very much late in the period, but with the increase in low level moisture expect feels like temperatures to once again approach 105-107F respectively. (Frye)

LONG TERM
(Friday night through Monday)
Issued at 104 AM CDT Tue Aug 4 2026

A fairly typical summertime pattern will be in place through the extended period.
Broad troughing extending across the central and eastern CONUS will keep stronger upper-level ridging displaced west of the region, while the western periphery of the Bermuda ridge maintains generally south to southeast low-level flow across the central Gulf Coast.
This will continue transporting deeper Gulf moisture into the area, with precipitable water values above 2 inches through much of the period.

With no well-defined synoptic forcing expected, convection will primarily be driven by daytime heating and mesoscale boundaries.
Showers and thunderstorms will initially develop over the coastal waters during the overnight and morning hours before transitioning inland along the sea breeze during the afternoon. Additional development will be possible along outflow boundaries from earlier convection. Scattered to numerous coverage is expected each day, generally favoring southern and coastal portions of the CWA early before spreading farther inland during peak heating. Weak steering flow through much of the column will favor slow-moving, pulse-type storms capable of producing frequent lightning, brief gusty winds, and locally heavy rainfall. Convective coverage and placement will likely vary considerably from one location to another each day.
Little meaningful change in the overall pattern is currently apparent Monday and Tuesday. The region should remain beneath weak flow aloft with ample moisture and only subtle forcing, allowing the daily marine and sea-breeze convective cycle to continue. Any weak perturbations embedded within the flow could locally enhance coverage, but confidence remains low regarding their timing and placement at this range.

Temperatures will be near to slightly above early-August normals.
Afternoon highs should generally reach the lower to mid 90s across inland areas, with upper 80s to lower 90s closer to the immediate coast. Earlier convective development may hold some locations several degrees cooler. Overnight lows will range from the lower to mid 70s inland to the upper 70s near the coast and tidal lakes. The combination of increasing humidity and temperatures in the 90s will produce afternoon heat index values generally in the 100 to 107 degree range. A few locations could briefly approach Heat Advisory criteria before convection develops, but widespread hazardous heat is not currently anticipated. (ME)

AVIATION
(12Z TAFS)
Issued at 517 AM CDT Tue Aug 4 2026

Mainly VFR conditions expected through the cycle. There is a small chance of a rogue shower or storm today, but chances and coverage are too low to mention at this juncture. Otherwise, light and variable surface winds expected across the region. (Frye)

MARINE
Issued at 104 AM CDT Tue Aug 4 2026

A frontal boundary has stalled right along the Gulf coast from Houston to Dauphin Island. Winds right along the boundary have diminished but south of there over the open Gulf waters are still west 10 to 15 knots with seas 2 to 4 feet. Both winds and seas should be subsiding as the pressure gradient relaxes Monday as the front gradually loses definition. Winds will generally remain west to southwest at 5 to 10 knots, although locally variable winds can be expected near the weak boundary and with the daily coastal circulations.

The surface high-pressure axis over the southern Gulf will become absorbed by the Bermuda ridge as the week progresses. This will alter flow to more of a south to southeast direction Thursday through the weekend. Speeds should generally remain around 5 to 10 knots, although periods of 10 to 15 knots will be possible over the outer waters as the easterly fetch becomes better established late in the week. Seas will generally remain 1 to 2 feet across the sounds and nearshore waters, with a gradual increase to 2 to 4 feet possible over portions of the outer waters Friday into the weekend.

Thunderstorm coverage will gradually increase Thursday through Sunday as deeper moisture returns. Development will tend to favor the open waters during the overnight and morning hours before shifting toward the sounds, tidal lakes, and adjacent coastal areas later in the day. (ME)

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