Marine Weather Net

Casco Bay Marine Forecast


TONIGHT

N
WINDS
10 - 15
KNOTS

TUE

NE
WINDS
5 - 10
KNOTS

TUE NIGHT

SE
WINDS
5 - 10
KNOTS

WED

S
WINDS
15 - 20
KNOTS

The Marine Weather Forecast In Detail:
ANZ153 Forecast Issued: 1046 PM EST Mon Nov 28 2022

Tonight...N Winds 10 To 15 Kt With Gusts Up To 25 Kt, Diminishing To 5 To 10 Kt Late. Seas 2 To 4 Ft.
Tue...Ne Winds 5 To 10 Kt, Becoming Se In The Afternoon. Seas Around 2 Ft.
Tue Night...Se Winds 5 To 10 Kt, Becoming S 10 To 15 Kt With Gusts Up To 20 Kt After Midnight. Seas 2 To 3 Ft.
Wed...S Winds 15 To 20 Kt With Gusts Up To 25 Kt, Increasing To 25 To 30 Kt With Gusts Up To 40 Kt In The Afternoon. Seas 2 To 4 Ft, Building To 4 To 6 Ft In The Afternoon. A Chance Of Rain In The Morning, Then Rain In The Afternoon With Vsby 1 To 3 Nm.
Wed Night...S Winds 25 To 30 Kt, Becoming W 20 To 25 Kt After Midnight. Gusts Up To 40 Kt. Seas 4 To 7 Ft. Rain. Vsby 1 To 3 Nm.
Thu...W Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft. Rain Likely In The Morning.
Thu Night...Nw Winds 15 To 20 Kt, Diminishing To 10 To 15 Kt After Midnight. Seas 2 To 4 Ft.
Fri...W Winds 5 To 10 Kt, Becoming Sw In The Afternoon. Seas 2 To 3 Ft.
Fri Night...Sw Winds 10 To 15 Kt. Seas 2 To 3 Ft.
Sat...Sw Winds 15 To 20 Kt. Seas 2 To 4 Ft. A Chance Of Showers.
Sat Night...W Winds 10 To 15 Kt. Seas 2 To 4 Ft. A Chance Of Showers.
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Area Forecast Discussion
National Weather Service Gray ME
1044pm EST Monday Nov 28 2022

Synopsis
High pressure will build across the region tonight with clearing skies and pleasant weather through the day tomorrow. Unsettled weather returns by Wednesday as rain and gusty southerly winds return the region ahead of a surface cold front. Colder on Thursday with gusty westerly winds and mountains snow showers possible. More rain possible by late week along with warm temperatures.

Near Term - Tonight
1045pm Another round of tweaks to the forecast, again hitting on the stratocu over the mountains spilling toward Penobscot Bay. In spite of every model having eroded this deck by now... it persists with nearly the same coverage it had around sunset. Thus I boosted sky coverage through tonight and upper overnight lows a bit where clouds will hang on longest.

600pm Mainly minor changes to the forecast with this update, targeting sky coverage in particular with stubborn stratocu still well entrenched up over the mountains but more broken in the lee of the mountains. Also added flurry mention back into the forecast across the higher terrain and adjacent valleys given mPing reports (and occasional -SN at KHIE/KBML) indicating as much.

Previously...Zonal 500mb flow will become established tonight along with surface ridging. This will lead to a downward trend in the northwest winds and cloud cover. Clouds will linger through midnight across the upslope regions of the north country along with a few flurries, but no accumulations are expected. Temperatures will trend colder tonight with lows more seasonable for this time of year with 20s and some teens across the mountain valleys. No significant weather is expected.

Short Term - Tuesday Through Tuesday Night
Tomorrow will most likely be the best weather day for the remainder of the week with the region under a shortwave ridge aloft along with the surface high pressure cresting over New England. This will lead to a call in wind speeds as flow begins to back to the south ahead of the approaching trough from the Ohio River Valley. Southerly winds will increase through Tuesday night across the higher terrain along with onshore flow along the coast. Expecting low temperatures to bottom out around midnight before increasing through the remainder of the night. Expect coastal areas to be back above freezing before daybreak. Models are hinting at a strong low level push late Tuesday night with the potential for some upslope moisture in the foothills. This would be interesting as temperatures will still be below freezing. I have introduced the mention of some mixed precipitation for a brief period at the onset of the Wednesday system.

Long Term - Wednesday Through Monday
A deepening low pressure will lift from just north of the Great Lakes toward Hudson Bay from Wednesday morning into Wednesday night, sending a strong cold front through the region late Wednesday evening into the early overnight hours. This system will bring strong winds to the area as well as widespread rainfall. Locally heavy rainfall is also possible and could result in some nuisance flooding, mainly toward the mountains where the ground is frozen.

Wednesday will start out mostly cloudy as southerly winds bring higher moisture into the region ahead of the front. WAA (Warm Air Advection - the movement of warm air) may develop a few showers the morning, possibly some mixed precipitation toward the mountains, but the bulk of the precipitation should hold off until the early afternoon. So going into the afternoon and evening, widespread rainfall is expected to overspread the area with moisture and lift continuing to increase over the region. At the same time, southerly winds will become gusty in response to the deepening low and tightening gradient. Wind gusts of 40-45 mph will be possible, especially along the coast, during the evening and early overnight hours. It should be noted that there will be a strong LLJ around 60 kt (closer to 70 kt per the NAM) in place during the evening, and there could be a brief period of damaging wind gusts during the frontal passage. Behind the front, westerly winds should be diminish somewhat during the overnight hours, but still could gust to 25-35 mph.

South of the mountains, rain will come to an end during the overnight hours from west to east as cooler and much drier air move in behind the front, but there could be a brief changeover to snow before the dry air wins out. For the mountains, precipitation will change to all snow during the overnight hours, which will likely continue while areas to the south dry out.

Thursday will be a blustery day with west to northwest winds gusting 30-40 mph, possible exceeding 40 mph at times during the late morning and afternoon hours. With strong cold advection, daytime temperatures won't recover much, and wind chills will be mainly in the 20s for most of the day, and much lower across the higher terrain. Increasing upslope flow through Thursday morning and afternoon will keep snow showers across the mountains/foothills, and conditions are looking favorable for some of the snow showers to be heavy with perhaps a snow squall or two. With Froude numbers also forecast to be high, some of this activity may spread to areas south and east of the mountains on Thursday morning and afternoon. To account for this have added some mentionable Probability of Precipitation south of the mountains in addition to going higher on sky cover.

Any activity that makes it south of the mountains will dissipate toward sunset on Thursday, but isolated to scattered snow showers will continue into early Thursday night across the mountains before eventually coming to an end as high pressure builds toward the region.

The high pressure will bring dry weather and lighter winds with high temperatures reaching the mid 30s to lower 40s on Friday. Another shortwave trough will move across the Great Lakes and toward New England over the upcoming weekend, sending the next cold front through. Southerly flow will increase ahead of the front on Saturday, moderating high temperatures close to 50 degrees in some spots. Timing of the front is a little better defined today, bringing in the higher precipitation chances Saturday into Saturday night rather than into Sunday, and models are again favoring a more inland track of the low, so this looks to be a mainly rain event outside of the mountains. Sunday and Monday look mostly dry as high pressure builds in behind the front, except for mountain snow showers on Sunday.

Marine
Short Term
SCA (Small Craft Advisory) post frontal conditions will continue through midnight before post frontal westerly winds begin to weaken before daybreak tomorrow. High pressure will briefly crest over the waters tomorrow with pleasant conditions. Southerly return flow will develop once again over the coastal waters after midnight and trend up towards daybreak.

Long Term
A low pressure passing to our north will send a strong cold front through the waters late Wednesday evening or Wednesday night. Gale conditions are likely ahead of the front as early as Wednesday afternoon as southerly winds rapidly increase, and these conditions are expected to continue into Wednesday night and much of Thursday as winds turn westerly behind the front. A Small Craft Advisory will then likely be needed as winds and seas diminish late Thursday or Thursday night. Conditions will continue to improve on Friday with high pressure in place, but southerly winds will again increase over the upcoming weekend as another cold front looks to cross the waters either late Saturday or Saturday night.

NOAA Gray/Portland ME Office - Watches - Warnings - Advisories
ME...None. NH...None.

Marine
Small Craft Advisory until 4am EST Tuesday for ANZ150>152-154.