Marine Weather and Tide Forecast for St. Martin, MS

LONG TERM
(Sunday through Wednesday night)
Issued at 231 PM CDT Thu May 15 2025

Sunday through Tuesday will be a persistence forecast as deep layer ridging dominates the Gulf South. Deep layer subsidence will keep temperatures warmer than average with highs climbing into the upper 80s and lower 90s each day and lows only dipping into the low to mid 70s. This subsidence and warming aloft will also keep the strong mid-level capping inversion in place, and this will keep convective chances near zero through Tuesday afternoon. The overnight cloud development will continue to occur as the inversion strengthens each night, but mostly sunny conditions will be the rule by the late morning and afternoon hours each day.

Wednesday will see a slight change in the pattern take hold as a potent northern stream trough axis and associated cold front sweep through the Lower Mississippi Valley. This fast moving feature will break down the persistent ridge and allow for the mid-level capping inversion to weaken. The combination of increased deep layer forcing, more favorable mid-level lapse rates, and ample warmth and available moisture will support the development of scattered convection during the day on Wednesday. At this time, the convection looks to remain below severe limits with some locally gusty winds and brief heavy downpours being the main threats. Temperatures will remain above average in advance of the front with highs warming back into the upper 80s and lower 90s.
However, in the wake of the front Wednesday night, slightly cooler and drier will advect into the region allowing lows to dip into the 60s.

AVIATION
(00Z TAFS)
Issued at 623 PM CDT Thu May 15 2025

Current VFR conditions across the area should remain in place through around 06Z. The same conditions as last night are expected to repeat with a temperature inversion bringing a MVFR stratus layer driving ceilings to 1000 to 2000 feet from 06Z through 14 to 15Z. After 15Z boundary layer mixing will allow the low stratus to lift and scatter returning conditions to VFR. /Schlotz/

MARINE
Issued at 231 PM CDT Thu May 15 2025

A gradually weakening pressure gradient across the coastal waters will keep winds slightly lower tonight than those observed last night. As a result, no small craft advisories are in place, but small craft exercise caution wording will be added to the forecast for the waters west of Port Fourchon. This will be the final night of stronger winds as the surface high over the eastern Gulf turns more dominant this weekend into early next week. The end result will be a persistent southerly flow of 10 to 15 knots from tomorrow through early next week.

PRELIMINARY POINT TEMPS/POPS
MCB 72 92 73 92 / 0 0 0 10 BTR 74 91 75 92 / 0 0 0 10 ASD 73 90 74 91 / 0 0 0 0 MSY 75 89 75 90 / 0 0 0 0 GPT 74 85 75 86 / 0 0 0 0 PQL 73 85 74 86 / 0 0 0 0

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