Marine Weather and Tide Forecast for Grand Isle, LA

SHORT TERM
(Now through Friday night)
Issued at 1245 PM CDT Tue Jun 9 2026

The area remains under a weak ridging pattern, helping to somewhat suppress rain and thunderstorm chances. However, did increase PoPs a little for this afternoon as a few of the CAMs are showing some isolated showers popping up. This is mainly for areas towards the Atchafalaya. Added 15% in for a good amount of the CWA and left in around 20-30% for the Atchafalaya.

In terms of temperatures, we will remain in the low to mid 90s through the short term period. In some areas this will be a couple degrees above climate normals, but for the most part we will be right around average for this time of year. Cloud cover is expected to be fairly light, so not a lot in the way of heat relief. However, any areas where those isolated showers and storms develop will bring some very brief relief.

LONG TERM
(Saturday through Monday night)
Issued at 1245 PM CDT Tue Jun 9 2026

Heading into the long term period, it is worth noting that heat indices will start to jump up into the 100-105F range. This comes as temperatures are expected to remain in the low 90s and we see an increase in moisture heading into the weekend. This increase in moisture is noticeable in the PoPs forecast as we start to get back into more of an areawide 30-40% each afternoon pattern.

There is a very large amount of model differences late in the period with the GFS showing a deepening trough moving from the Northwest down across the Northern Plains. This helps push the lingering frontal boundary that was sat north of our area down into our area, stalling it through the end of the period. This would bring a rather wet pattern back into the area next week. The Euro still pushes that lingering front down here, but it gets pushed more so from the troughing over the Northeast U.S rather than a shortwave coming down from the Plains. So similar outcomes, but very different overall upper level patterns.

AVIATION
(00Z TAFS)
Issued at 609 PM CDT Tue Jun 9 2026

Mostly VFR conditions through the cycle. There will likely be some VIS reductions for BTR and MCB (generally MVFR or IFR), but this should improve quickly after sunrise on Wednesday. Otherwise, convection coverage will be minimal. Best chances will be around BTR, but even then it will be too isolated and low PROB to mention at this juncture. Otherwise, light to moderate southerly winds are expected. (Frye)

MARINE
Issued at 1245 PM CDT Tue Jun 9 2026

For the remainder of this week, winds will remain ESE to SE at 10 to 15 knots. Low numbers of showers and storms will remain as well but winds and seas will be higher in and near any thunderstorm activity that does occur.

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