Marine Weather Net

Lake Pontchartrain and Lake Maurepas Marine Forecast


REST OF TONIGHT

W
WINDS
25
KNOTS

SUNDAY

NW
WINDS
25 - 30
KNOTS

SUNDAY NIGHT

NW
WINDS
15 - 20
KNOTS

MONDAY

NW
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
GMZ530 Forecast Issued: 858 PM CST Sat Jan 15 2022

GALE WARNING IN EFFECT THROUGH SUNDAY AFTERNOON
Rest Of Tonight...West Winds 25 To 30 Knots. Waves 3 To 6 Feet. Dominant Period 4 Seconds. Slight Chance Of Showers Early In The Evening.
Sunday...Northwest Winds 25 To 30 Knots. Waves 3 To 5 Feet With Occasional Waves To 6 Feet. Dominant Period 4 Seconds.
Sunday Night...Northwest Winds 15 To 20 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds.
Monday...Northwest Winds 10 To 15 Knots. Waves 2 To 4 Feet. Dominant Period 4 Seconds.
Monday Night...North Winds 5 To 10 Knots Becoming Northeast After Midnight. Waves 1 Foot Or Less. Dominant Period 4 Seconds.
Tuesday...Southeast Winds Near 10 Knots. Waves 1 To 2 Feet. Dominant Period 4 Seconds.
Tuesday Night...Southeast Winds Near 10 Knots. Waves 1 To 2 Feet. Dominant Period 4 Seconds.
Wednesday...South Winds 10 To 15 Knots. Waves 2 To 4 Feet. Dominant Period 4 Seconds. Slight Chance Of Showers In The Afternoon.
Wednesday Night...Southwest Winds 10 To 15 Knots Becoming Northwest 15 To 20 Knots After Midnight. Waves 2 To 4 Feet. Dominant Period 4 Seconds. Chance Of Showers And Slight Chance Of Thunderstorms In The Evening, Then Showers Likely After Midnight.
Thursday...North Winds 15 To 20 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds. Chance Of Showers.
Thursday Night...North Winds 15 To 20 Knots. Waves 2 To 4 Feet. Dominant Period 4 Seconds. Slight Chance Of Light Rain Through The Night.
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Synopsis for Pascagoula to SW Pass Mississippi - GMZ501
Synopsis for SW Pass Mississippi River to Atchafalaya River- GMZ500
858 PM CST Sat Jan 15 2022

A strong cold front is moving through coastal waters this evening and tonight followed by high pressure building in for the early to middle parts of next week.
Area Forecast Discussion
National Weather Service New Orleans LA
345am CST Sunday Jan 16 2022

Synopsis
Upper low early this morning looks to be in the vicinity of Jackson, MS. Upper ridging along the Pacific Coast, with a weaker upper low well to the west of Los Angeles. At the surface, low pressure appears to be centered over western Alabama. Radars and surface observations aren't indicating any precipitation over or near our CWA at this time. That being said, wouldn't be out of the question for radars from KLIX/KDGX/KPOE to be shooting above any snow flurries or sprinkles over SW Mississippi, as the beams are around 9000-12000 feet over Wilkinson County. Temperatures were generally in the 30s at 3am CST, with breezy to windy conditions.

.SHORT TERM (through Tuesday night)... Will hold onto the Wind Advisory for now south of Lake Pontchartrain, although not seeing a lot of observations sustaining 25 mph at this time.

Really the only forecast issues in the short term will be today, with the low end potential of some snow flurries north, and the timing of clearing later in the day, with it's associated impact on high temperatures.

Upper low appears to be at the base of the longwave trough and should begin to lift northeastward this morning. Some question as to how saturated the airmass is over southwest Mississippi. The special 06z LIX sounding showed the airmass pretty much bone dry above 5000 feet, and questionable whether it's cold enough to promote snowfall. The JAN sounding at the same time showed a healthy saturated layer from about 3000 to 10000 feet and cold enough to support snow. Water Vapor imagery does show that the dry slot is likely to exit the southwest Mississippi area in the next few hours. Will assume that the moist layer over southwest Mississippi will be somewhere in the middle of the 2 soundings, say at about 7000-8000 feet. Will continue the possibility of a few snow flurries across southwest Mississippi through mid morning, but at this time, don't anticipate major impacts.

Low confidence in any significant clearing much prior to sunset with a cold upper low and low level thermal troughing in the area. If there's a preferred area for clearing prior to late afternoon, it'd probably be the southwest third of the area, say west of a Baton Rouge to Grand Isle line. Trending on the cool side of guidance for highs today.

Once the low starts pulling out today, high pressure will build in from the west. By Tuesday afternoon, it will be centered over the Carolinas with onshore flow returning locally. Beyond this evening, don't expect much in the way of clouds, let alone precipitation until Tuesday night. NBM and operational model guidance numbers generally in the same ballpark for tonight through Tuesday night, so really no significant targets of opportunity to make any real improvements in the temperature forecast. 35

.LONG TERM (Wednesday and beyond)... After a few dry days, this portion of the forecast period will be the beginning of a relatively wet period. Zonal upper level pattern over the southeast will be transitioning into troughing as one dives south out of Canada on Wednesday. A cold front associated with this feature will just be moving into northern LA/MS midday, which means it wouldn't be reaching the CWA until late afternoon and into the evening hours. The same goes for rainfall from this system. A swath of showers and a few thunderstorms, mostly post frontal, will steadily be tracking southeast across the local area Wednesday evening and generally pushing offshore by Thursday morning. At least thats what the GFS indicates. The ECMWF (European Centre for Medium-Range Weather Forecasts) suggests continued isentropic lift behind the front which will keep rain going through Thursday. NBM carrying a fair portion of its Probability of Precipitation weight on the ECMWF. GFS performance has been better for quite some time and wouldn't be surprised if its solution does better with this forecast period. Regardless, drastic drop in temps expected with this frontal passage. After mid to possibly even upper 70s on Wednesday, highs will struggle to reach the 50s in some locations on Thursday. A series of reinforcing troughs look to maintain below normal temp pattern through the weekend with low, but non-zero, rain chances. Will need to monitor for frozen precipitation chances if cold stays in place while shortwaves pass through. For now, in coordination with WFO MOB, trending toward a somewhat drier solution than the NBM for next weekend.

Marine
Will hold onto the Gale Warning for now, and allow day shift to pare it back, or replace it with a Small Craft Advisory as conditions dictate. May be able to drop the lakes and sounds prior to the 21z CWF issuance, but doubtful it happens much before that. Small Craft Advisories will likely be necessary for about 12 hours after the Gale Warnings. Conditions should relax Monday and Tuesday, with moderate onshore flow returning by Wednesday. With the passage of a new cold front Wednesday night into Thursday, Small Craft Advisories are likely to again become necessary. Those may need to be continued into next weekend. 35

NOAA New Orleans LA Office: Watches - Warnings - Advisories
LA...Wind Advisory until noon CST today for LAZ060-061-063-064- 066>070-077-078.

GM...Gale Warning until 6pm CST this evening for GMZ530-532-534-536- 538-550-552-555-557-570-572-575-577.

MS...None. GM...Gale Warning until 6pm CST this evening for GMZ532-534-536-538- 550-552-555-557-570-572-575-577.