Marine Weather and Tide Forecast for Chalmette, LA

SHORT TERM
(Now through Thursday)
Issued at 147 AM CDT Mon Aug 3 2026

The cold front has nearly stalled over the southern portions of Louisiana this morning leaving some locations south of the I-10 corridor fairly "soupy" if you will. North of the I10/12 corridor, however, humidity values are a bit more comfortable. Eventually the front will continue downstream clearing most of the region and allowing the more comfortable dry air to filter further south. At the surface, northerly winds/offshore flow will be on the light side, but a favorable direction for hotter temps. Since humidity values are lower, no need for heat headlines with most locations experiencing "feels like" temperatures at or below 105F during peak heating. Taking a look at the mid and upper levels, there remains a ULL over the Tennessee River Valley with some weak upper level troughing over there region. Again, due to favorable wind direction, the lower heights will not provide much temperature relief, but again at least RH values are reasonable.

As for rainfall, overall chances are not zero, but pretty close.
If there is an exception it would likely be during the diurnal cycle offshore at night and right along the sea breeze closer to the Gulf coast. (Frye)

LONG TERM
(Thursday night through Sunday)
Issued at 147 AM CDT Mon Aug 3 2026

A broad upper level trough will be track through the mid section of the country Thursday, crossing the mid and upper Mississippi River Valley during the overnight period. This will put the CWA within a region of minimal subsidence with no ridging aloft. At the same time, moisture recovery will be underway as onshore flow brings deeper Gulf moisture inland Friday through Saturday. Forecast PW increases from 1.5" range to over 2". Despite not having a well- defined synoptic trigger, strong daytime heating with driving temps into the mid 90s will easily initiate convection on the inland- moving sea breeze moisture convergence boundaries. Scattered convection. Weak flow through much of the column will favor slow- moving, pulse-type storms rather than organized convection. The usual summertime hazards of frequent lightning, brief gusty winds, and locally heavy rainfall will accompany the stronger storms.
Temperatures should run near to slightly above early-August normals, particularly across inland portions of the CWA Afternoon highs will generally reach the lower to mid 90s. Increasing moisture will push afternoon heat indices upward later in the week, but the current forecast keeps most locations below the 108 degree Heat Advisory threshold. A few locations could approach that level before convection develops, particularly this weekend. (ME)

AVIATION
(12Z TAFS)
Issued at 518 AM CDT Mon Aug 3 2026

Mostly VFR conditions expected through the cycle. There are a few ongoing VIS issues for terminals south of I10, but any fog will dissipate shortly after sunrise. Overall, northerly winds will remain on the weaker side through the period. (Frye)

MARINE
Issued at 147 AM CDT Mon Aug 3 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.