Marine Weather and Tide Forecast for Gretna, LA

SHORT TERM
(Now through Saturday night)
Issued at 1226 PM CDT Wed Jul 8 2026

Generally, upper level conditions are reflective of the typical summertime pattern with high pressure stretching from the Atlantic Bermuda high westward to the desert southwest. There are some weaknesses in the northcentral Gulf coast that allow shallow intrusions of lower pressure and weak troughing. At the surface, the Bermuda high extends into the north central Gulf providing some light southerly flow around its western periphery. Typical weather pattern is daytime highs in the low to mid 90s and apparent temperatures just below the 108 degree theshold for heat headlines, overnight lows hang in the upper 70s giving slight opportunities for cooling, and convection is governed by sea breeze boundaries and remnant boundaries after intial convection collapses.

LONG TERM
(Sunday through Tuesday night)
Issued at 1226 PM CDT Wed Jul 8 2026

That weak trough described in the short term conditions will move from the Ohio Valley Saturday, into our area by Monday and into the eastern Gulf Tuesday. A weak surface boundary may also be associated with the trough.

Precipitable water values are expected to be near or above the 90th percentile Saturday night through Monday (2.10 inches) and possibly topping out around 2.3 inches on Monday before dropping to near the mean (1.7 inches) by late Tuesday. This should enhance (scattered to numerous) convective coverage during convectively favored times Sunday and Monday...peak heating hours over land zones, late night and morning in marine areas. Of course, with precipitable water values that high, there will be a threat of at least localized heavy rainfall, but pinpointing exactly where that will occur 5 or 6 days from now is problematical. As the column dries out somewhat late on Tuesday, we'll probably see less areal coverage of convection, and a lesser threat of heavy rainfall, but low level lapse rates steepen and DCAPE values increase to over 1000 j/kg, so the wind threat will increase.

Still looks to be rather warm on Sunday, as storms may not develop until mid-afternoon, with highs probably 90 to 95. Areal coverage of storms increases Monday and likely develops a little earlier, so slightly lower high temperatures should be expected. Guidance from the Tuesday global operational models was within a degree or two of each other, so there's not likely to be much of a shift in the NBM numbers. Won't entirely rule out the need for a Heat Advisory Sunday, but at this point, the numbers say it's borderline at best.

AVIATION
(18Z TAFS)
Issued at 1226 PM CDT Wed Jul 8 2026

VFR conditions predominate and will continue through the period, with the exception that scattered convection is possible.
Conditions will deteriorate in the vicinity of any storms that do develop.

MARINE
Issued at 1226 PM CDT Wed Jul 8 2026

Winds shift to due south then to the southeast by the weekend but remain around 10kt. Scattered showers and storms can be expected each day, mostly during the morning hours. A few may be strong producing erratic gusty winds and/or waterspouts, with locally hazardous seas.

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