Casco Bay Marine Forecast
|Tonight...Ne Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft.|
|Tue...Ne Winds 10 To 15 Kt With Gusts Up To 20 Kt, Becoming E 5 To 10 Kt In The Afternoon. Seas 2 To 4 Ft.|
|Tue Night...Sw Winds Around 5 Kt, Becoming Nw After Midnight. Seas 2 To 3 Ft.|
|Wed...N Winds Around 5 Kt, Becoming E In The Afternoon. Seas 2 To 3 Ft.|
|Wed Night...S Winds Around 5 Kt In The Evening, Becoming Light And Variable. Seas 2 To 3 Ft.|
|Thu...Ne Winds Around 5 Kt, Becoming Se In The Afternoon. Seas Around 2 Ft.|
|Thu Night...Sw Winds Around 5 Kt, Becoming Nw After Midnight. Seas 2 To 3 Ft.|
|Fri...Ne Winds Around 5 Kt, Becoming Se In The Afternoon. Seas 2 To 3 Ft.|
|Fri Night...S Winds Around 5 Kt, Becoming W After Midnight. Seas 2 To 3 Ft.|
|Sat...N Winds Around 5 Kt, Becoming Se In The Afternoon. Seas 2 To 3 Ft.|
|Sat Night...Sw Winds Around 5 Kt, Becoming Nw After Midnight. Seas 2 To 4 Ft.|
| Area Forecast Discussion|
National Weather Service Gray ME
759pm EDT Monday September 25 2023
High pressure remains largely in control over northern New England through much of this upcoming week. High pressure becomes centered over New England through the end of the work week. This will bring fair and dry conditions, with light winds. Cool nigheights are expected with some scattered frost possible in the far north Tuesday night.
Near Term - Through Tuesday
755 PM...Only real changes to forecast involve the fact that boundary layr decoupling is occur across most f the area away from the coast /taking a little longer there, but may happen there as well/. Winds have dropped off to less than 5 kts in many inland spots, and this may allow for a bit more rad cooling inland, so mins were bumped down, especially in the N valleys, by a degree or so.
Previously...A much drier airmass has made a pretty big southward push since this morning, which has allowed the sun to come out over most of the area...with the exception of the southern NH, where light rain or sprinkles may result in another hundredth or two of accumulations over the next couple of hours. The northeast flow from building high pressure will continue to bring the drier air southward through tonight, clearing out skies for the rest of the area, although models are hinting at some cloud cover redeveloping across southern NH overnight.
The clear skies will allow for good radiational cooling in places that are able to decouple, and I think the best chance of this is across the north, closer to the center of the high. Have leaned on the cooler side of guidance here (MAV and MET MOS), putting lows in the mid to upper 30s along with the potential for frost and/or fog. Elsewhere, I haven't gone quite as cool with thinking that winds will stay up enough to keep us somewhat mixed, especially farther south one goes (but still 40s along with some lower 50s).
Short Term - Tuesday Night
Valley fog that develops tonight should lift by 9am or so Tuesday morning. Otherwise, high pressure and the dry airmass will provide a mostly sunny day for Tuesday with highs in the 60s, perhaps hitting 70 degrees in a couple of spots.
High pressure settles more overhead for Tuesday night, which will give us more ideal conditions for radiational cooling. Lows across most of the area look to fall into the upper 30s to lower 40s, with even low-mid 30s possible across the northern valleys and other normally cooler spots. This may end up resulting in the first frost headlines for portions of the area this season. Patchy fog is possible as well.
Long Term - Wednesday Through Monday
Dry weather is expected through much if not all of the long term period as deep layer high pressure remains in control. This will result in cool nigheights and increasingly warm days. The next chance of measurable rain could be with a cold front Monday or Tuesday of next week.
Expect patchy fog to continue to form during the overnight hours. This will mainly be confined to the inland valley floors.
SCA (Small Craft Advisory) conditions continue into Tuesday morning, perhaps early afternoon. Northeast flow remains breezy through tonight, but will start to lessen toward daybreak and then continue the downward trend through the day Tuesday. Winds will be light and out of the north to northeast Tuesday night.
The next chance of marginal SCA (Small Craft Advisory) conditions may come Saturday as some swells make their way into the Gulf of Maine.
NOAA Gray/Portland ME Office - Watches - Warnings - Advisories
Small Craft Advisory until 11am EDT Tuesday for ANZ150-152- 154.