Marine Weather Net

Vermilion Bay Marine Forecast


REST OF TONIGHT

W
WINDS
UP TO
5 KNOTS

WEDNESDAY

NE
WINDS < 5
KNOTS

WEDNESDAY NIGHT

S
WINDS
UP TO
5 KNOTS

THURSDAY

NE
WINDS
5 KNOTS

The Marine Weather Forecast In Detail:
GMZ435 Forecast Issued: 948 PM CDT Tue Jul 27 2021

Rest Of Tonight...Southwest Winds Up To 5 Knots. Bay Waters Smooth.
Wednesday...Northeast Winds Up To 5 Knots Becoming South In The Afternoon. Bay Waters Smooth. Chance Of Showers And Thunderstorms In The Afternoon.
Wednesday Night...South Winds Up To 5 Knots. Bay Waters Smooth. Slight Chance Of Showers And Thunderstorms In The Evening.
Thursday...Northeast Winds Around 5 Knots Becoming Southeast In The Afternoon. Bay Waters Smooth. Chance Of Showers And Thunderstorms In The Morning, Then Showers And Thunderstorms Likely In The Afternoon.
Thursday Night...South Winds Around 5 Knots. Bay Waters Smooth.
Friday...Southwest Winds Up To 5 Knots. Bay Waters Smooth. Slight Chance Of Showers And Thunderstorms In The Morning, Then Chance Of Showers And Thunderstorms In The Afternoon.
Friday Night...Southwest Winds Around 5 Knots. Bay Waters Smooth.
Saturday...West Winds 5 To 10 Knots. Bay Waters A Light Chop. Slight Chance Of Showers And Thunderstorms In The Morning, Then Chance Of Showers And Thunderstorms In The Afternoon.
Saturday Night...Southwest Winds 5 To 10 Knots. Bay Waters A Light Chop.
Sunday...Southwest Winds 5 To 10 Knots. Bay Waters A Light Chop. Slight Chance Of Showers And Thunderstorms In The Morning, Then Chance Of Showers And Thunderstorms In The Afternoon.
Sunday Night...Southwest Winds 5 To 10 Knots. Bay Waters A Light Chop. Slight Chance Of Showers And Thunderstorms After Midnight.
SHARE THIS PAGE:           
Synopsis for Lower Atchafalaya River LA to High Island TX out 60 NM including Sabine and Calcasieu Lakes and Vermilion Bay: GMZ400
948 PM CDT Tue Jul 27 2021

Light and variable winds are expected through Wednesday. Weak high pressure building across the northwest Gulf of Mexico through the end of the week will allow for light onshore winds to become more prevalent. There will be daily chances for shower and thunderstorm activity. Locally higher winds and seas, along with cloud to water lightning can be expected near the storms.
Area Forecast Discussion
National Weather Service Lake Charles LA
1150pm CDT Tuesday July 27 2021

For 06z TAF issuance.

UPDATE... The vast majority of the widespread convection that developed across the region this afternoon has dissipated or will do so shortly as the atmosphere has been pretty well worked over. A robust thunderstorm complex continues across parts of Liberty and Chambers county this evening which did not see as much in the way of convection earlier today.

A typically warm, humid and quiet night is expected with scattered diurnally driven convection once again expected to initialize by late Wednesday morning through early Wednesday evening. As was mentioned previously, a somewhat drier pocket of mid level air is forecast to move from east to west across the northern gulf tomorrow as it wraps around the southeastern periphery of the sprawling upper ridge over the central U.S. This could put something of a limit on convection near the coast, but still expect development further inland. Away from storms, heat indices will once again be near 105. Current thinking is that the cloud cover and convection should hold most of the area below heat advisory criteria.

Only changes to the forecast this evening were minor updates to PoPs and dewpoints to reflect the latest observations.

AVIATION... Local 88Ds show the bulk of the convection ongoing across the forecast area is associated with a lingering outflow boundary shifting outward from its genesis over cntl LA...and thus POPs were retained in this set of TAFs for the southern terminals (just VCSH was kept at KAEX where lingering stratiform rains were noted). Otherwise VFR conditions should continue to prevail outside of the storms. After a quiet night, tomorrow looks like a relative repeat of today, although only vicinity mentions were included at this time.

SYNOPSIS... KLCH and KPOE radars show sctd showers and storms developing acrs cntl LA with more widely sctd convection across Beauregard Parish into SE TX just north of Beaumont.

PWATs (Precipitable Waters) across the area are generally above 2 inches per recent GOES TPW and LAPS Layer Precip Water Analysis, and this corresponds to at least the 75th percentile to near the 90th percentile of Storm Prediction Center sounding climatology. Although general weak surface high pressure prevails acrs the region, subtle boundaries/convergence zones are providing enough low level forcing for convective development, and further supported by a disturbance aloft on the southeast periphery of a large upper level ridge centered over the Front Range and cntl High Plains.

Prior to and outside of showers and storms, temperatures have been in the lower to middle 90s across much of the area. Corresponding heat index readings have been generally between 100 and 107 degrees, although a few locations have exceeded 108 degrees.

24

SHORT TERM [Tonight through Thursday night]... Expect convection to persist through early this evening, gradually diminishing around sunset, although a few showers or storms could linger a few hours beyond as there will still be sufficient CAPE to support development along boundary interactions. That said, convection should be pretty much done by midnight. Another warm and muggy night on tap with lows mostly in the middle 70s.

Sctd showers and storms are expected to develop again on Wednesday. However, a pocket of drier air (currently poised off the S cntl LA coast) will be shifting westward toward the TX coast. This could help to lower rain chances slightly, especially for areas along and south of I-10. PWATs (Precipitable Waters) are forecast to remain elevated across the northern half of the area, with values near 2 inches across the northern tier of Parishes and Counties, thus expect more sctd coverage in these areas during the afternoon. Outside of any showers or storms, afternoon highs are expected to again reach the lower to middle 90s. As is the case today, expect heat indices to exceed 100 degrees across the area, with a few isolated spots near or just above advisory criteria of 108 for an hour or two. Fcst Max Apparent T shows this is likeliest to occur across portions of cntl LA. Given the isolated and short-lived nature of these potential heat indices, have opted not to issue a Heat Advisory at this time.

Deeper moisture is expected to return areawide on Thursday. The sprawling upper ridge is expected to remain centered northwest of the region, allowing for another weak disturbance to travel across the region. This will spell yet another day of daytime showers and storms, with the highest chances confined across south cntl LA. High temperatures will again be in the 90s, with heat index values generally from 100 to 105 degrees.

Showers and storms on both Wednesday and Thursday could produce brief heavy rainfall. However, amounts are not expected to be excessive and, for the most part, should stay under an inch.

24

LONG TERM [Friday through Tuesday]... Mid to upper level high pressure ridge will continue to dominate the area Friday through Sunday. Afternoon highs in the mid to upper 90s north of I-10, with lower to mid 90s south. Heat index values expected to rise into the 104-107 degree range. Precipitation chances around 30-40% along the I-10 corridor, 20-30% further north.

For Monday and Tuesday, the mid to upper level ridge will retreat further westward as a deep layer mid to upper level trough digs further southward across the Eastern U.S. This may actually allow for a weak cool front to move across the area, still up for debate how much drier air it may bring. However, fronts this time of year usually bring increased chances of precipitation, especially when they stall over or just north of the region. Most blended guidance shows increased chances of showers and thunderstorms beginning late Monday afternoon, continuing through the night into Tuesday.

Marine Discussion
Light and vrbl winds are expected over the coastal waters through Wednesday. Onshore flow is expected to become more prevalent through the latter part of the week as surface high pressure builds west acrs the Gulf of Mexico.

Winds are expected to remain light and seas low through the period. Widely scattered showers and tstms will be possible, mainly from late night through the morning. A little higher chance for showers and tstms is expected from Thursday into Friday as a weak disturbance moves west across the Gulf.

24.

NOAA Lake Charles LA Office: Watches - Warnings - Advisories
LA...None. TX...None. GM...None.