Chandeleur Sound Marine Forecast
|Rest Of Tonight...Northeast Winds 15 To 20 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds. Chance Of Showers Early In The Evening. Slight Chance Of Thunderstorms Through The Night. Showers Likely After Midnight.|
|Tuesday...Northeast Winds 20 To 25 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds. Showers Likely In The Morning. Chance Of Thunderstorms Through The Day. Showers In The Afternoon.|
|Tuesday Night...North Winds 20 To 25 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds. Chance Of Showers Early In The Evening.|
|Wednesday...North Winds 15 To 20 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds.|
|Wednesday Night...North Winds 10 To 15 Knots. Waves 2 To 4 Feet. Dominant Period 4 Seconds.|
|Thursday...North Winds 10 To 15 Knots. Waves 1 To 2 Feet. Dominant Period 4 Seconds.|
|Thursday Night...West Winds Near 5 Knots Becoming Northeast 10 To 15 Knots In The Late Evening. Waves 1 To 2 Feet. Dominant Period 4 Seconds.|
|Friday...East Winds 10 To 15 Knots. Waves 1 To 2 Feet. Dominant Period 4 Seconds. Slight Chance Of Showers In The Afternoon.|
|Friday Night...Northeast Winds 15 To 20 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds. Chance Of Showers And Slight Chance Of Thunderstorms.|
|Saturday...North Winds 15 To 20 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds. Slight Chance Of Showers In The Morning.|
|Saturday Night...Northeast Winds 15 To 20 Knots. Waves 3 To 5 Feet. Dominant Period 4 Seconds.|
| Synopsis for Pascagoula to SW Pass Mississippi - GMZ501|
Synopsis for SW Pass Mississippi River to Atchafalaya River- GMZ500
846 PM CST Mon Mar 1 2021
A low pressure system is forecast to form along a stalled frontal boundary across the north-central Gulf of Mexico and pass through the waters on Tuesday. Offshore flow will return behind the front as high pressure builds in from the northwest on Tuesday and Wednesday. High pressure will move east across the region Thursday and early Friday, then another low pressure system is expected to move through the north Gulf on Friday night and Saturday morning.
| Area Forecast Discussion|
National Weather Service New Orleans LA
1135pm CST Monday Mar 1 2021
Evening Update: /issued 925pm CST Monday Mar 1 2021/
Performed a forecast update this evening to reflect obs/radar trends as well as short-range guidance through Tuesday afternoon. The cold front that passed through the area is on its way well south into far outer marine zones this evening, with gusty northeasterly winds prevailing and remaining especially strong across marine areas where Small Craft Advisories are currently in effect through 9AM. Just some lingering post-frontal stratiform showers and drizzle lie in its wake with chilly overnight temperatures. Main focus shifts back to the west as a surface low pressure area continues to develop along the front, roughly 100mi SE of Galveston, TX, with an 850MB low tilted just to the northwest across coastal Texas. As this surface to 850mb low approaches from the west, winds in the low levels will steadily increase owing to intensifying WAA/isentropic upglide above the shallow post-frontal airmass in place. CAM's illustrate this process well with showers increasing in coverage around or just before 06Z for western areas, particularly south of I-10/12 with coverage spreading north and east through early Tuesday. As this 850MB low tracks across just north of the CWA into south-central MS, so will the region of maximized omega/vertical ascent in the low-levels right above the frontal inversion per HRRR (High-Resolution Rapid Refresh) soundings for midday Tuesday. Given this, NBM thunder probabilities did come up enough to propose a few thunderstorms, as elevated parcels lifted from around 800-825mb indicates enough instability to produce cloud to cloud lightning in the lower to mid troposphere. This is very reasonable going through short-range guidance tonight and will let the mention of showers and thunderstorms ride through the day on Tuesday.
Otherwise, the surface low looks to track just along or south of the SE LA coastline during the day. Depending on the exact location of the low and how far north the warm sector pulls into our far outer Marine zones will depend if any stronger surface- based storms develop. But this threat will be confined to right at the low and to the south and east into the warm sector. Good news is this system will be fast to depart late Tuesday, with most rain coming to an end around sunset with gusty northerly winds building in behind the system. Expect Small Craft Advisory conditions for marine zones to come during this time frame in subsequent updates. KLG
Short Term - Tonight Through Thursday
A potent shortwave trough will move east across the southern plains and Arklatex region tonight and Tuesday morning. A west to east oriented cold front has pushed through most of the forecast area today, and this boundary will continue pushing south into the north Gulf coastal waters tonight. Isentropic lift north of the boundary will result in areas of rain and possibly a few thunderstorms from time to time in southern areas tonight. The shortwave trough will continue to move east across the lower Mississippi valley Tuesday afternoon and evening with the associated surface low moving east along the old frontal boundary that will drifting north just off the southeast Louisiana coast. Widespread rain showers and a chance of thunderstorms will accompany this system, however once again severe thunderstorm appear unlikely due to cooler low level temperatures and fairly weak mid level lapse rates. Rainfall amounts should be decent, but not excessive with average amounts expected to range from .75 to 1.5 inches. Drier and cooler conditions will prevail with the sun returning on Wednesday as high pressure builds in behind the front and low pressure area. The surface high will continue to build in on Thursday with a modifying airmass allowing high temperatures to push back up near normal in the mid to upper 60s.
LONG TERM (Friday through Monday)... The next potent shortwave trough will move southeast through the central Gulf coast region late Friday, Friday night and early Saturday morning. The models continue to depict moderate to locally heavy precipitation amounts with this system mainly late Friday and Friday night, however once again severe thunderstorms look unlikely. Most of the weekend should see surface high pressure in control and dry and mild weather if this system continues to time out like the models currently indicate.
A cold front will continue to push south into the northern Gulf and stall out tonight. Cold air advection behind the front and high pressure building in from the north will result in northeast winds picking up to 15 to around 20 knots through tonight. Have issued Small Craft Advisories for portions of the eastern coastal waters and sounds late this evening through mid morning on Tuesday. "Exercise Caution" headlines are in effect in most remaining waters tonight.
A low pressure system is forecast to form along the front and then pass through the waters on Tuesday. Offshore flow will return behind the front as high pressure builds in from the northwest on Tuesday night through Thursday. A renewed period of near or exceeding Small Craft Advisory criteria winds is likely to need additional headlines Tuesday night. Showers and thunderstorms will be most numerous through Tuesday then drying out Wednesday and Thursday. Winds and waves will subside later on Wednesday through Thursday as high pressure builds into the region. Yet another low pressure system will move across the north Gulf late Friday and Friday night brining another period of moderate to stronger winds and increased wave heights.
NOAA New Orleans LA Office: Watches - Warnings - Advisories
LA...None. GM...Small Craft Advisory until 9am CST Tuesday for GMZ534-536-538- 550-552-555-557-570-572-575-577.
MS...None. GM...Small Craft Advisory until 9am CST Tuesday for GMZ536-538-550- 552-555-557-570-572-575-577.