Marine Weather and Tide Forecast for Long Beach, MS

LONG TERM
(Saturday through Wednesday night)
Issued at 300 PM CDT Thu May 22 2025

As the frontal boundary to the north creeps southward over the weekend, and mid level flow becomes southwesterly, conditions will gradually become more favorable for increased areal coverage of showers and storms. The operational GFS solution is slower to do this than the ECMWF. The ECMWF indicates this could happen as early as Saturday afternoon, but more definitively Sunday, continuing through midweek and beyond. The greatest potential for showers and storms looks to be during the afternoon hours Tuesday and Wednesday. The GFS operational solution is much less aggressive, holding rain chances in the 20-30 percent range during much of that period. The NBM solution is much more representative of the ECMWF operational numbers. Did not deviate from the NBM PoPs from Sunday onward, but if it appears that the GFS becomes more representative of expectations, those numbers would need lowered in later forecasts. With precipitable water values expected to be in the 1.6 to 1.8 range during the first half of next week, there will be potential for heavy rainfall. However, by that point, it will have been two weeks or more since most areas will have seen significant rainfall, lowering any flash flooding threat, at least initially.

High temperatures will be impacted by how much convection develops during the afternoon hours. Where convection develops, high temperatures will top out in the mid 80s. Where convection is more limited, highs will be around 90, give or take a couple degrees.
With the PoP forecast being somewhat more driven by the ECMWF scenario, the NBM high temperature numbers also resemble the ECMWF high temperature guidance.

AVIATION
(18Z TAFS)
Issued at 1226 PM CDT Thu May 22 2025

VFR at all terminals with the exception of KHUM, where MVFR ceilings are in place. Frontal boundary that moved through the area yesterday, may have already dissipated, as dew points have already increased to around 70 to the south of Interstate 10, and winds become east to southeast. Convection to the south of Terrebonne Parish (south of KHUM) has shown no inclination to work northward. Any warming at all this afternoon should lift cloud bases at KHUM above FL030. Primarily VFR overnight, but some threat of light fog at KMCB. Will mention MVFR visibilities there, but guidance has been too aggressive on very low conditions there recently. With higher dew points in place tomorrow, likely to be a brief period of MVFR ceilings as cumulus field develops, but not confident for any length of time prior to 18z.

MARINE
Issued at 300 PM CDT Thu May 22 2025

Main concern for marine operations through the 5 day forecast period will be the threat of thunderstorms producing localized higher winds and season. Aside from thunderstorm development, winds should generally remain less than 15 knots and seas in the 1 to 3 foot range.

PRELIMINARY POINT TEMPS/POPS
MCB 68 90 70 90 / 0 10 0 20 BTR 70 91 73 92 / 10 20 0 20 ASD 69 90 72 90 / 0 10 0 20 MSY 74 89 75 90 / 10 10 0 20 GPT 70 88 73 87 / 0 0 0 10 PQL 66 91 71 89 / 0 0 0 10

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