Marine Weather Net

Calcasieu Lake Marine Forecast


REST OF TONIGHT

N
WINDS
15 - 20
KNOTS

TUESDAY

N
WINDS
15 - 20
KNOTS

TUESDAY NIGHT

NE
WINDS
10 - 15
KNOTS

WEDNESDAY

E
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
GMZ432 Forecast Issued: 853 PM CST Mon Nov 11 2019

SMALL CRAFT ADVISORY IN EFFECT THROUGH TUESDAY AFTERNOON
Rest Of Tonight...North Winds 15 To 20 Knots. Lake Waters Rough. Rain Showers Likely.
Tuesday...North Winds 15 To 20 Knots. Lake Waters Rough. Slight Chance Of Rain Showers In The Morning.
Tuesday Night...Northeast Winds 10 To 15 Knots. Lake Waters Choppy.
Wednesday...East Winds 5 To 10 Knots. Lake Waters A Light Chop.
Wednesday Night...Northeast Winds 5 To 10 Knots. Lake Waters A Light Chop. Slight Chance Of Rain Showers.
Thursday...Northeast Winds 5 To 10 Knots. Lake Waters A Light Chop. Chance Of Rain Showers.
Thursday Night...North Winds 5 To 10 Knots. Lake Waters A Light Chop. Chance Of Rain Showers.
Friday...North Winds 5 To 10 Knots. Lake Waters A Light Chop.
Friday Night...Northeast Winds 5 To 10 Knots. Lake Waters A Light Chop.
Saturday...Northeast Winds 5 To 10 Knots. Lake Waters A Light Chop.
Saturday Night...Northeast Winds Around 5 Knots. Lake Waters Smooth.
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Synopsis for Lower Atchafalaya River LA to High Island TX out 60 NM including Sabine and Calcasieu Lakes and Vermilion Bay: GMZ400
853 PM CST Mon Nov 11 2019

An arctic cold front will move through the coastal waters tonight with gale conditions developing behind the front. Winds and seas will subside Tuesday night, with a light to modest offshore flow prevailing Wednesday and Thursday.
Area Forecast Discussion
National Weather Service Lake Charles LA
1132pm CST Monday Nov 11 2019

UPDATE... As of 9 PM, local surface observations indicate that the leading edge of the cold front extends from near Marksville south- southwestward to just west of Cameron. Sustained winds behind the front have generally been ranging from 15 MPH to 25 MPH with gusts up to 45 MPH being reported. Therefore, based on the 9PM location of the front, the Wind Advisory that was currently in effect was expanded to include: Allen, Beauregard, Calcasieu, Cameron, Jefferson Davis, Rapides, and Vernon Parishes. The timing for the Wind Advisory for the rest of the forecast area remains unchanged with it going into effect at midnight and continuing through mid- day Tuesday.

Cold air advection is resulting in surface temperatures falling into the 50s and 40s across portions of the CWA that are behind the front. Areas of rain showers are also noted behind the front on the regional radar mosaic. A band of steadier precipitation is noted behind the front roughly collocated with the maximum 700-850 hPa frontogenesis. There have been some reports of sleet mixing in with this area of steadier rain across central Texas where cold air advection has cooled a sufficient depth of the atmosphere to allow for pockets of precipitation to refreeze before hitting the ground. While it can't be entirely ruled out that a few sleet pellets could mix in with the light rain tonight, the latest model guidance continues to indicate that moisture will be exiting the region by the time the atmospheric temperature profile will be supportive of sleet. Therefore, have continued to leave only light rain in the forecast for the overnight period.

The main update to the forecast this evening was to bring an end to the precipitation across the region more quickly during the day tomorrow. Latest short term model guidance has most precipitation moving offshore by mid-morning. Meanwhile, steady northerly winds will continue to advect colder air into the region and keep temperatures in the 40s tomorrow.

AVIATION... Cold front currently moving through southeast Texas just northwest of Beaumont Texas at this time and extends up into Vernon parish. Frontal system is moving to the east southeast. Winds ahead of the strong cold front are from the south generally less than 10 knots while behind the front winds become northwest to north at 20 to 25 knots w/ higher gusts. Ceilings are also dropping from VFR ahead of the front to IFR behind the front and to LIFR deeper into the front. VSBY to vary from 5sm to P6sm thru the overnight hours. The issue of the eve and ovrnght hrs will be low ceilings and very strong gusty winds.

The front is expected through AEX and LCH by 02z and thru LFT and ARA by 04z.

SYNOPSIS... A significant early arctic cold front is expected to move across tonight with high rain chances just along and behind the front. Blustery north winds behind the front will provide a dramatic change in temperatures with conditions more like the heart of winter than fall and probably some of the coldest air since January 2018.

Bullet Points... Near record breaking low temperatures expected for Tuesday night and Wednesday morning. There is a likelihood of an area wide freeze with a hard freeze down to the I-10 corridor. Precautions for plants, pets, pipes, and people should be taken. Hard Freeze and Freeze Watches have been issued.

Estimated duration below freezing Tuesday night/Wednesday morning... Central Louisiana...around 12 hours. Lakes and Piney s Southeast Texas...10 to 12 hours. Along the I-10 corridor...6 to 10 hours. South of I-10 corridor to the coast...3 to 6 hours.

Blustery north winds will make for a raw day on Tuesday with wind chills in the 20s in the morning and 30s in the afternoon. This will be a dramatic change from apparent temperatures in the upper 70s today. The north winds may also cause some travel problems for high profile vehicles and blow around unsecured lawn objects. A Wind Advisory has been issued.

Strong and gusty north winds will create hazardous marine conditions with winds offshore gusting at times between 45 and 50 knots late tonight and on Tuesday. A Gale Warning will be in effect.

It is unlikely any frozen type precipitation falls in the forecast area. Even if a brief period of sleet mixing in with the rain can occur in the far northern zones late overnight and very early Tuesday morning, the impacts will not be significant.

Mild temperatures occurring across the forecast area this afternoon with readings mainly in the mid to upper 70s. However, these temperatures are just teasing as to what is expected to be on the way as dramatic changes will occur tonight into Tuesday.

The culprit for the dramatic airmass change is a sharp northern stream upper level trough that is amplifying as it moves east of the Rockies and across the Plains. This will allow a 1043 hPa surface high with polar origins to build southward and push an arctic intrusion down to the Gulf coast.

The arctic cold front is making good progress through Texas and as of of 11/21Z has moved through the San Antonio to Texarkana areas. Good agreement with the front moving into the forecast area right before sunset for northwest areas, then through the remainder of the forecast area during the evening hours, before being off the coast by midnight.

Moisture profiles have been increasing as mid and upper level southwest winds are bringing East Pac moisture at those levels and low level southerly flow is bringing in Gulf moisture. Precipitable water according to latest LAPS analysis are ranging from 1.5 to 1.75 inches.

As is typical with these types of fronts, best frontal convergence and lift is right along and behind the front, and this is when the interaction with the good moisture with allow widespread rain showers to develop with the shield of rain showers marching south during the evening and overnight as the front quickly moves through. Instability looks rather weak so will keep activity as showers and not mention any thunder. With the high moisture values could be some moderate rainfall with the activity.

The question as to any wintry mix. At this time, consensus of forecast soundings, top-down procedure, and other local winter weather procedures, show that when favorable thermal parameters develop, and surface temperatures drop to near freezing, moisture is lacking. As the arctic airmass is shallow, even the worse case or best case (depending on how you look at it) for any wintry precipitation have about a 7-9 thousand foot warm layer above 95H with temperatures in the layer around 5C. Then a small layer of sub-freezing above the surface, before temperatures at the surface again go above freezing.

Therefore, there is an outside chance that a few sleet pellets may mix in before the moisture ends across the very extreme northern zones for one or two hours after 3 am til around sunrise. However, with surface temperatures remaining above freezing and drying quickly after sunrise, anything would be insignificant and will not mention any frozen precipitation in the zones or grids.

A big drop in temperatures will occur, as afternoon temperatures on Tuesday will be some 30F to 35F degrees lower than from Monday afternoon, as temperatures struggle to get into the 40s. It will also be a raw day, as blustery north winds will help keep wind chills in the 20s during the morning and 30s in the afternoon.

Wind speeds behind the front will be around 20 mph with gusts to around 30 mph or higher into Tuesday afternoon, so will have a Wind Advisory going to cover this.

Clearing skies and winds becoming light as the strong high pressure settles in on Tuesday night and Wednesday morning look to make for very cold conditions and more like a January cold blast than one in November, and quite likely this will be the coldest airmass since January 2018.

Guidance operational mos numbers are still coming into better agreement, with ECMWF-ECM, GFS-MAV, NAM-MET operational numbers all within one to three degrees of each other, and also very close to the mean and 50 percentile ensemble member numbers. Even the 90 percentile ensemble numbers, or in theory how cold it should at-least get show a freeze area wide with a hard freeze for the northern zones.

Therefore, will go with a blend of the operational guidance and this gives near record or record breaking cold temperatures for the lows on Tuesday night/Wednesday morning, and an area wide freeze will occur, with a potential hard freeze down to the I-10 corridor. Upgrades to Hard Freeze Warnings and Freeze Warnings will come later once we pin down the fine details with local hard freeze criteria temperatures 25F degrees and below.

Warming trend will start during the day on Wednesday and into Wednesday night as the high begins to weaken and move off to the east.

Still some differences going into Thursday with a southern stream short wave moving across and how much return flow moisture it can work with. GFS is on the dry side with best moisture mainly for along the coast and offshore and ECMWF (European Centre for Medium-Range Weather Forecasts) is a little more wet, with moisture for the entire forecast area. The good news is that the rainfall amounts would be light if it occurs or not. At this point will keep close to the national blend and super blend numbers for the late Wednesday night into Thursday period.

Temperatures overall during the period look to be below climo norms into the weekend.

Marine Discussion
An arctic cold front will enter the coastal waters before midnight and sweep through the coastal waters before daybreak. A 1043 hPa surface high building in behind the front will allow for a tight pressure gradient across the northwest Gulf of Mexico. Also, strong cold air advection will be noted behind the front bringing cold air over relatively warmer Gulf waters. This will allow rather turbulent conditions and mixing bringing strong and gusty north winds down to the surface. As the winds increase, seas will also build becoming quite rough.

Sustained winds tonight into Tuesday afternoon are expected to be 30 to 35 knots with gusts over 45 knots over the coastal waters with seas building to 7 to 11 feet beyond 20 nm and 3 to 7 feet within 20 nm. Therefore, a Gale Warning has been issued.

For the coastal lakes and bays winds will be 20 to 25 mph with higher gusts, so a Small Craft Advisory has been issued for those areas.

Usually we would see quite a drop in waters levels, especially out of the lakes and bays, as the offshore winds push water away from the coast. Guidance does show tide levels will be about 1 to 1.5 feet mllw below astronomical levels during low tide Tuesday morning. However, with current anomalies being between 0.5 and 1 foot above, this will help mitigate some of the water drop, and probabilistic tide guidance has lowest water levels around (-0.7) feet mllw, which does not quite reach the levels for a low water advisory, and thus will hold off on issuing one for now.

Winds will decrease by Wednesday as the high pressure settles in and weakens over the region.

Climate
Perspective on upcoming forecasted cold snap compared to records... Wednesday 11/13 Nov all time Last time 25F or below Fcst Daily Record Low Low Record

AEX 21F 27F/1911 20F 11/30/1911 25F 3/5/2019*

BPT 27F 28F/1911 22F 11/30/1976 23F 1/18/2018

LCH 26F 26F/1911 20F 11/30/1911 20F 1/18/2018

LFT 25F 27F/1911 21F 11/16/1916 17F 1/18/2018

ARA 26F 32F/1950 23F 11/30/1976 19F 1/18/2018

*AEX low on 1/18/2018 was 14F.

NOAA Lake Charles LA Office: Watches - Warnings - Advisories
LA...Freeze Watch from Tuesday evening through Wednesday morning for LAZ052>055-073-074.

Wind Advisory until 3pm CST Tuesday for LAZ041-042-073-074.

Hard Freeze Watch from Tuesday evening through Wednesday morning for LAZ027>033-041>045.

Wind Advisory until 3pm CST Tuesday for LAZ029-032-033-043>045- 052>055.

Wind Advisory until noon CST Tuesday for LAZ027-028-030-031.

TX...Freeze Watch from Tuesday evening through Wednesday morning for TXZ215.

Wind Advisory until 3pm CST Tuesday for TXZ215-216.

Hard Freeze Watch from Tuesday evening through Wednesday morning for TXZ180-201-216-259>262.

Wind Advisory until noon CST Tuesday for TXZ180-201-259>262.

GM...Small Craft Advisory from 6pm Tuesday to midnight CST Tuesday night for GMZ450-452-455-470-472-475.

Gale Warning until 6pm CST Tuesday for GMZ455-475.

Gale Warning until 6pm CST Tuesday for GMZ450-452-470-472.

Small Craft Advisory until 3pm CST Tuesday for GMZ430-432.

Small Craft Advisory until 6pm CST Tuesday for GMZ435.