Casco Bay Marine Forecast
|Tonight...N Winds 10 To 20 Kt With Gusts Up To 30 Kt. Seas 4 To 7 Ft. Rain. Vsby 1 To 3 Nm After Midnight.|
|Tue...N Winds 5 To 10 Kt, Becoming W In The Afternoon. Seas 3 To 5 Ft. A Chance Of Rain In The Morning With Vsby 1 To 3 Nm.|
|Tue Night...N Winds 5 To 10 Kt. Seas 2 To 4 Ft.|
|Wed...N Winds 5 To 10 Kt. Seas 2 To 3 Ft. Scattered Showers. Vsby 1 To 3 Nm In The Morning.|
|Wed Night...N Winds 5 To 10 Kt, Becoming Nw 10 To 15 Kt After Midnight. Seas 2 To 3 Ft.|
|Thu...Nw Winds 5 To 10 Kt. Seas 2 To 3 Ft.|
|Thu Night...Nw Winds Around 5 Kt, Becoming Sw After Midnight. Seas 1 To 2 Ft. A Chance Of Showers After Midnight With Vsby 1 To 3 Nm.|
|Fri...Sw Winds 5 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. Showers Likely.|
|Fri Night...Nw Winds 10 To 20 Kt With Gusts Up To 25 Kt. Seas 2 To 4 Ft. A Chance Of Showers. Vsby 1 To 3 Nm.|
|Sat...Nw Winds 10 To 20 Kt With Gusts Up To 25 Kt. Seas 2 To 4 Ft.|
|Sat Night...W Winds 5 To 10 Kt. Seas 1 To 2 Ft.|
Area Forecast Discussion|
National Weather Service Gray ME
822pm EST Monday Nov 18 2019
Low pressure off the Mid Atlantic coast will move northward into the Maritimes tonight. A light wintry mix is expected to change to rain over southern and coastal sections by evening. In the mountains and foothills, freezing or frozen precipitation is expected to linger through Tuesday morning. The next weather system looks to move eastward across the forecast area late in the week, possibly followed by another low pressure system later in the weekend.
Near Term - Until 6am Tuesday Morning
Update... Have updated the forecast per latest radar imagery and surface observations. Rain continues to fall over southern Maine and southern New Hampshire where winter weather advisories have expired. There will be pockets of sleet and freezing rain over central areas, where winter weather advisories remain in effect. Dry air continues to slow the advance of precipitation into northern Maine.
Temperatures will likely hover in the lower to mid 30s throughout the night with little change.
Prev Disc... At 19z a 995 millibar low was situated southeast of the benchmark. Steadier precipitation from this system continues to spread westward into the area. While we're warming aloft the cold air has been slow to erode away from the immediate coast. With precipitation onset there should be enough cooling of the column for at least a brief transition to light freezing or frozen precipitation through early evening over may areas immediately inland from the coast. For that reason...I've extended portions of the advisory until 9 PM. Across the mountains and foothills we should remain cold enough for light freezing and frozen precipitation overnight. The steadier precipitation should taper for a time overnight as the first impulse and surface low begin to pull away. However...a second impulse will be approaching from our southwest towards dawn along with a second batch of precipitation. Temperatures tonight will range from near 30 in the mountains to lower and mid 30s elsewhere.
Short Term - 6am Tuesday Morning Through Tuesday Night
Another quick round of steadier precipitation on Tuesday morning as the second impulse crosses the area. Across the mountains we should mixed precipitation changing to snow. Elsewhere...mainly rain should fall possibly mixed with a bit of sleet. Highs should be mainly in the 30s with a few 40 degree readings over southeast New Hampshire and the southwest Maine coast. Partial clearing outside the mountains Tuesday night as we're briefly between disturbances. Clouds from the next ocean low should arrive across the area by Wednesday morning.
Long Term - Wednesday Through Monday
An active pattern will continue through the next week. Trough over the Great Lakes will move through our area in the start of the week before making way for a ridge mid week. The next disturbance drops out of the north for the end of the week. Lots of variability for the end of the week as a closed low and blocking pattern out of the Pacific makes it tough for much to get through.
Wednesday another coastal low passes well off shore. While the main precipitation will be further east than our area, there is some potential for an inverted trough to bring some light precipitation into the ME/NH border and have increased Probability of Precipitation slightly to chance along this region. Overcast skies will also be present throughout the day with just a chance for clearing overnight on Thursday as the low moves further east.
High pressure builds in from the west for Thursday. As temperatures aloft rise through the end of the week surface temperatures will return to near normal values with highs in the mid 40s. In the south have increased temperatures slightly as the clearing skies should help out a bit.
Overnight Thursday into Friday flow will turn southerly as warm advection begins ahead of the next system. Increasing clouds may even lead to some light drizzle by early morning as lower levels become saturated.
The warm advection continues on Friday as temperatures soar to over 50 degrees across southern NH. Low pressure will develop over the Great Lakes and track north of the region. On Friday as the warm front lifts northwards we will see scattered showers with rain south and snow aloft. We remain in the warm sector until late on Friday when the cold front will move through with a burst of precipitation and a shift to NWly cold advection. With a potentially strong frontal passage will have to be alert for the potential for snow squalls in the mountains.
The progressive pattern looks to continue into the weekend with another low passage on Sunday.
/Through Tuesday Night/...Gale force wind gusts continue in a few locations, but we should be able to lower to gales to Small Craft Advisories over the next few hours as the strongest gradient shifts east.
Long Term...Another low will pass east of the waters on Wednesday with just a few lingering showers over the waters. High pressure will build across the region late Thursday before the next low moves through on Friday. Cold front will cross the waters late Friday night with Gales possible under cold advection.
Tides / Coastal Flooding
Seas will very slowly subside as we head into the next high tide. This tide is astronomically lower then this afternoon's, so any splash-over should be less of an issue.
NOAA Gray/Portland ME Office - Watches - Warnings - Advisories
ME...Winter Weather Advisory until 11am EST Tuesday for MEZ007>009- 012>014. NH...Winter Weather Advisory until 11am EST Tuesday for NHZ001>005- 007.
Small Craft Advisory until 5am EST Tuesday for ANZ151-153. Small Craft Advisory until 5pm EST Tuesday for ANZ150-152-154.