Marine Weather Net

Southwest Pass of the Mississippi River to Port Fourchon Louisiana Marine Forecast


TONIGHT

S
WINDS
5 - 10
KNOTS

WEDNESDAY

S
WINDS
5 - 10
KNOTS

WEDNESDAY NIGHT

S
WINDS
5 - 10
KNOTS

THURSDAY

SE
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
GMZ552 Forecast Issued: 401 PM CDT Tue Jun 22 2021

Tonight...South Winds 5 To 10 Knots. Seas 2 To 4 Feet. Dominant Period 6 Seconds. Slight Chance Of Showers And Thunderstorms Early In The Evening. Slight Chance Of Showers And Thunderstorms After Midnight.
Wednesday...South Winds 5 To 10 Knots. Seas 2 To 4 Feet. Dominant Period 6 Seconds. Chance Of Showers And Thunderstorms Until Late Afternoon.
Wednesday Night...South Winds 5 To 10 Knots. Seas 2 To 4 Feet. Dominant Period 6 Seconds. Slight Chance Of Showers And Thunderstorms Through The Night.
Thursday...Southeast Winds 5 To 10 Knots. Seas 1 To 2 Feet. Dominant Period 6 Seconds. Chance Of Showers And Thunderstorms Through The Day.
Thursday Night...Southeast Winds 5 To 10 Knots. Seas 1 To 2 Feet. Dominant Period 5 Seconds.
Friday...Southeast Winds 10 To 15 Knots. Seas 1 To 2 Feet. Dominant Period 5 Seconds. Chance Of Showers And Thunderstorms.
Friday Night...Southeast Winds 10 To 15 Knots. Seas 2 To 4 Feet. Dominant Period 4 Seconds. Slight Chance Of Showers And Thunderstorms After Midnight.
Saturday...East Winds 10 To 15 Knots. Seas 3 To 5 Feet. Dominant Period 7 Seconds. Chance Of Showers And Thunderstorms.
Saturday Night...Southeast Winds 10 To 15 Knots. Seas 3 To 5 Feet. Dominant Period 7 Seconds. Chance Of Showers And Thunderstorms Through The Night.
Sunday...Southeast Winds 10 To 15 Knots. Seas 2 To 4 Feet. Dominant Period 6 Seconds. Showers Likely And Chance Of Thunderstorms.
Sunday Night...Southeast Winds 10 To 15 Knots. Seas 2 To 4 Feet. Dominant Period 6 Seconds. Chance Of Showers And Thunderstorms.
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Synopsis for Pascagoula to SW Pass Mississippi - GMZ501
Synopsis for SW Pass Mississippi River to Atchafalaya River- GMZ500
401 PM CDT Tue Jun 22 2021

Upper level shortwave trough and other minor disturbances aloft are expected to remain or move near the coast and north Gulf waters for the next few days before high pressure tries to build into the area. Thunderstorms can be expected near the coast for the next several days and nights.
Area Forecast Discussion
National Weather Service New Orleans LA
438pm CDT Tuesday Jun 22 2021

Short Term - Tonight Through Friday
A more typical, but still slightly wetter than average summer day is ongoing this afternoon with radar indicating scattered to numerous showers and isolated to scattered thunderstorms on the numerous surface/low level boundaries across the forecast area. We have not seen much in the way of heavy rain issues in populated areas thus far, but that will remain a concern into the early evening. The Flash Flood Watch will remain in effect until 7 pm this evening, but it should not need to be extended in time. Cannot rule out some isolated flooding issues north of the watch area through early evening. Showers should become less numerous with lower rainfall amounts as the evening progresses as some drier air filters in from the north. Boundary collisions, movement of convection and the moisture and instability profiles have not been favorable for strong or severe storms today.

The central Gulf coast region will remain in northwest/north flow aloft on the periphery of a large high pressure dome over the southern Plains and western Gulf coast region. Precipitable water values are expected recover back to 1.9 to 2.1 inches Wednesday afternoon with some lingering, slightly drier air in the far north across interior south Mississippi. This moist airmass will remain in place through Thursday and Friday which will support scattered to numerous, mostly afternoon showers and thunderstorms each day. The threat of locally heavy rainfall will exist each day as well, but am not anticipating enough of a threat to reissue Flash Flood Watches. Temperatures are expected to remain a bit below normal to near normal for highs due to the high rain chances, but a bit above normal for lows due the very humid conditions.

Long Term - Saturday through Tuesday


An amplification of a mid/upper level trough will occur over the northern/central Plains/upper Mississippi Valley area while a large inverted trough sets up in the Gulf of Mexico going through the weekend into early next week. This will basically keep a favorable pattern in place along with a continued maintenance of fairly deep tropical moisture across the forecast area. While some models indicate some drier days with lower scattered coverage, the NBM is not lowering the Probability of Precipitation much on any given day with scattered to numerous, mostly afternoon showers and thunderstorms expected. Typical summertime thunderstorm hazards will continue to be possible with frequent lightning from a few storms along with heavy downpours and a few waterspouts in the marine area. Have stayed very close the NBM for this forecast. Temperature trends should be staying near to mostly below 90 for highs with the higher rain chances.

Marine
Main marine concern over the next few days will continue to be the threat of thunderstorms. Prevailing winds will mostly top out in the 10 to 15 knots range through the weekend, so am not really anticipating any wind- related headlines over the coastal waters through the end of the week and weekend.

NOAA New Orleans LA Office: Watches - Warnings - Advisories
LA...Flash Flood Watch until 7pm CDT this evening for LAZ056>061- 063>070-075>078.

GM...None. MS...Flash Flood Watch until 7pm CDT this evening for MSZ077-080>082.

GM...None.