Casco Bay Marine Forecast
|Tonight...S Winds 5 To 10 Kt With Gusts Up To 20 Kt, Becoming Se 10 To 15 Kt With Gusts Up To 25 Kt After Midnight, Then Increasing To 20 To 25 Kt With Gusts Up To 30 Kt Late. Seas 2 To 4 Ft. A Slight Chance Of Snow After Midnight. A Chance Of Snow And Rain Late.|
|Mon...E Winds 30 To 40 Kt With Gusts Up To 60 Kt, Becoming S 25 To 30 Kt With Gusts Up To 45 Kt In The Afternoon. Seas 6 To 9 Ft. Rain With Snow Likely In The Morning, Then Rain With A Chance Of Drizzle In The Afternoon.|
|Mon Night...Sw Winds 20 To 25 Kt, Becoming W 15 To 20 Kt After Midnight. Seas 5 To 8 Ft.|
|Tue...W Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 4 To 6 Ft, Subsiding To 2 To 4 Ft In The Afternoon.|
|Tue Night...Nw Winds 15 To 20 Kt, Becoming W 10 To 15 Kt After Midnight. Seas 2 To 4 Ft.|
|Wed...W Winds 5 To 10 Kt, Becoming S 10 To 15 Kt In The Afternoon. Gusts Up To 25 Kt. Seas 2 To 4 Ft. A Chance Of Snow Or Rain In The Afternoon.|
|Wed Night...Sw Winds 10 To 15 Kt With Gusts Up To 25 Kt. Seas 2 To 4 Ft. A Chance Of Snow. A Chance Of Rain After Midnight.|
|Thu...Nw Winds 10 To 15 Kt. Seas 2 To 3 Ft. A Chance Of Snow Showers In The Morning.|
|Thu Night...N Winds 10 To 15 Kt. Seas Around 2 Ft.|
|Fri...N Winds 10 To 15 Kt. Seas 1 To 2 Ft.|
|Fri Night...N Winds 10 To 15 Kt. Seas Around 2 Ft.|
| 330 PM EST Sun Jan 16 2022 |
Synopsis for Stonington ME to Merrimack River MA out to 25 NM - ANZ100
Low pressure tracks north through the Appalachians and into Canada tonight into Monday. A warm front lifts across the Gulf of Maine with strong southeast winds expected Monday morning. Winds shift to south and weaken later in the day, then shift to the west overnight as cold air moves back in.
| Area Forecast Discussion|
National Weather Service Gray ME
353pm EST Sunday Jan 16 2022
Low pressure tracking northward through the Appalachians will intensify as it tracks near New England on Monday. It will bring a period of heavy snow changing to rain as the temperature warms. Strong winds are also expected, especially along the coast. Low pressure pulls away Monday night with colder air moving in for the middle of the week. A weak system passes by to our north Wednesday and Thursday.
Near Term - Tonight
High pressure pulls away to the east tonight while low pressure tracks north through the Appalachians. With a clear sky to start the night, we may see some decent drops in temperature before cloud cover comes in and blankets the area. Winds become easterly by morning in advance of the incoming low pressure system. Precipitation will likely begin by dawn for much of the area with snow the precipitation type expected. More on the storm in the short term section.
Short Term - Monday Through Monday Night
Narrow band of warm, moist air being pulled into the low pressure system will translate northeast across our forecast area during the morning hours on Monday. A strong low level jet will be adding fuel to the system to produce heavy precipitation rates over the period of 4 to 8 hours. At the surface, the very cold air mass we've been dealing with the last few days will be hard to shove away by the less dense warm air. The easterly low level flow and inverted low level thermal profile will promote damming east of the mountains and the formation of a coastal front between this colder air and the more maritime air being pulled in off the Atlantic. The strong surge of moisture into this coastal front will likely be the source of the most intense precipitation through the morning, with the coastal front making progress inland with time. Thus we will see a transition from heavy snow to rain as the coastal front marches inland, with the precipitation itself ending rather quickly as as the dry slot moves in aloft. We could see a period of drizzle or freezing drizzle (depending on the temperature in each location) after the dry slot moves through, although it should be rather insignificant compared to the heavier precipitation that falls just ahead of it.
Behind the coastal front, the low levels will be less inverted allowing greater access to the extreme low level jet above, thus bringing the threat for some high winds. This threat will be greatest at the immediate coastline, but stronger wind gusts will be possible further inland as well once the coastal front arrives. Current High Wind Warning covers this threat well and will continue.
As for the snowfall itself, I think the biggest factor here is the intense snowfall rates expected as the surge of moisture slams into the coastal front. Snowfall rates of 1 to 3 inches per hour are likely which is enough to overwhelm road clearing operations and create more difficult driving conditions than usual. As a result, we were a bit more liberal than normal in placing Winter Storm Warnings as these heavy snowfall rates will create very difficult driving conditions for a period of a few hours Monday morning, even if the total snowfall is a bit less than 6 inches. The change over to rain on top of the snow will also make for more slippery conditions as well. The total snowfall amounts themselves are still somewhat uncertain considering the complication of heavy snowfall rates and an advancing coastal front which moves the rain/snow line. This is particularly true in coastal areas including the Portland metro which could see several inches pile up quickly if cold air holds on, or on the other extreme it could just start as rain.
As the warm front lifts northward, winds become southerly and weaken, while temperatures warm into the 30s and 40s. The warm front clears the forecast area by mid afternoon, and precipitation south of this front should be mainly in the form of drizzle if it occurs. Colder air wraps in behind the low Monday night, with an area of lift potentially wrapping around for some more light snow before ending, mainly in the mountains.
Long Term - Tuesday Through Sunday
Very cold and windy conditions will occur Tuesday around the periphery of the departing storm system. This could aggravate and potential power outage issues as wind chill values lower with time. Otherwise dry conditions through Tuesday night with wind chill values running from zero to 25 below during the nighttime period.
12Z operational guidance and model ensembles remain in relatively good agreement bringing an area of low pressure up the Saint Lawrence Seaway Wednesday into Thursday. The highest chance for snowfall will be over northern areas where light accumulations of snow can be expected.
A cold, Canadian high pressure system will build into the region Friday. Temperatures by Saturday morning will remain below zero across most of the region away from the coast.
Low pressure may move up the Eastern Seaboard next weekend, however there is little agreement amongst the operational or ensemble solutions. The Canadian model is the outlier at this time, bringing a storm near the 40N/70W benchmark Saturday night.
Easterly flow increases ahead of a warm front lifting northward attached to a strong surface low tracking to our west. Winds ramp up quickly in a narrow 4 to 8 hour window Monday morning with gusts to Storm Force expected. Some gusts to Hurricane Force are also possible especially across the eastern Gulf of Maine. Winds shift to the SSW and weaken behind the warm front around midday. Eventually a shift to westerly flow in cold advection begins late Monday night.
Gale force winds are expected on Tuesday and Tuesday night around the periphery of the departing storm system. Winds remain strong with SCA (Small Craft Advisory) conditions possible Wednesday into Wednesday night as winds back to the west and southwest.
Heavy rain is expected on the coast after a short period of snow Monday. With frozen ground in place, urban flooding will be possible as 1-2 inches of rain is expected.
Tides / Coastal Flooding
The strongest winds of our upcoming storm match up closely with the time of high tide. Still expect a 2-3 foot storm surge during the mid to late morning high tide on Monday using a blend of the latest ESTOFS and ETSS runs. Storm force winds will allow for 20+ foot waves to develop offshore as well as the nearshore environment. Therefore, beach erosion and splash-over may be significant in some areas, especially coastal Cumberland, Coastal York and Coastal Rockingham counties where Coastal Flood Warnings have been issued.
NOAA Gray/Portland ME Office - Watches - Warnings - Advisories
ME...Winter Storm Warning from 1am to 4pm EST Monday for MEZ012>014-018>021-033. Winter Storm Warning from 3am to 7pm EST Monday for MEZ007>009. High Wind Warning from 5am to 4pm EST Monday for MEZ022>028. Coastal Flood Advisory from 9am to noon EST Monday for MEZ025>028. Winter Weather Advisory from 1am to 1pm EST Monday for MEZ022>024. Coastal Flood Warning from 9am to noon EST Monday for MEZ023- 024. NH...Winter Storm Warning from 1am to 4pm EST Monday for NHZ004>012-015. Winter Storm Warning from 3am to 7pm EST Monday for NHZ001>003. High Wind Warning from 5am to 4pm EST Monday for NHZ014. Winter Weather Advisory from 1am to 1pm EST Monday for NHZ013. Coastal Flood Warning from 9am to noon EST Monday for NHZ014.
Storm Warning from 5am to 4pm EST Monday for ANZ150>154.