Marine Weather and Tide Forecast for Rockland, ME

NEAR TERM /THROUGH TUESDAY/
1130 PM Update... Minor changes to reflect latest observational trends.

Previously...
930 PM Update... Went ahead and issued a coastal flood statement for the entire coast for the high tide cycle at around midnight.
Latest observations are close to the forecast, which approaches minor flood stage later tonight. Otherwise, just loaded in the latest surface observations to account for the fast cooling that is taking place.

Previously...
745 PM Update... Minor changes to reflect latest observational trends. Satellite imagery shows cirrus coming in from the north and west but this is rather thin and high in altitude and therefore should not have a major impact on radiational cooling.

Previously...
Very warm and dry conditions are making for a very pleasant spring day across the forecast area. Northwest winds are doing a good job of keeping the sea breeze at bay...so even the coast has managed some 70s.

Tonight return flow will commence as high pressure slides to our south. Despite that I suspect we will be able to decouple and radiate...so I took our favored cool spots and adjusted temps down a few degrees overnight. With southerly winds starting to creep up the CT River Valley I do not anticipate fog developing like last night.

SHORT TERM /TUESDAY NIGHT/
Tue is still the pick of the week...with widespread temps well into the 70s for most areas and perhaps a few 80s across southern NH. Breezy southwest winds will keep the sea breeze pinned near the Seacoast and southwestern ME coast...but it will surge inland towards the Capital Region. I have blended in some higher resolution temps to show the marine influence there.
Southwest winds will also be bringing increasing dewpoints thru the day...so even though temps will be warmer the RH values may be a few percentage points higher thanks to the moisture advection.

Question then becomes when does the cold front arrive with convection. Some CAM guidance shows prefrontal trof convection as early as 4 PM...while the frontal precip does not arrive until closer to 8 PM. Marginal risk for severe storms is clipped just to the west of the North Country currently...which is probably right considering storms arriving as the boundary layer is stabilizing is most likely
However
if we can get the earlier arrival time of storms we will have to watch out for deep moderately strong westerly flow leading to gusty winds.

Overnight temps will remain quite mild...closer to the high temps for this time of year...as a steady breeze remains.

LONG TERM /WEDNESDAY THROUGH MONDAY/
04Z Long Term Forecast Update... Little change in the latest NBM guidance. Conditions look to become unsettled late Thursday night through portions of the upcoming weekend, although dry periods will likely be mixed in between.

Previously...
A drier and slightly cooler airmass settles in behind the cold front for Wednesday and Thursday as high pressure builds in. Temperatures will be still be mostly in the 60s each day, although the seabreeze will probably keep the coast in the 50s on Thursday. The breezy northwest winds will likely be enough to prevent the seabreeze Wednesday. Dry air and subsidence will bring plenty of sunshine Wednesday, but we should start seeing more mid and high clouds move in Thursday afternoon as moisture starts to increase ahead of the next system.

The high shifts east Thursday night into Friday with a 500mb trough moving across the Great Lakes turning the weather turning more unsettled through at least the first of the weekend with mostly cloudy conditions and multiple chances for showers. The first round of showers will likely move in Thursday night into the first part of Friday along a warm front. The cold front then enters the area Friday into Saturday with waves of low pressures riding along it, potentially bringing multiple rounds of showers across the region. We may to add a chance of thunderstorms for Friday afternoon (mainly NH) if we can get some clearing/destabilization.

Outside of precipitation, the increasing southerly flow will probably bring low stratus and fog to portions of the area, mostly likely in western ME and along the coast. This will also keep western ME cooler on Friday with highs in the 50s and 60s while southern NH could still reach the 70s.

By Sunday into next Monday, there is decent agreement among the models showing the low pressure and cold front east of the area, although the GFS is slower in doing so with the trough becoming more amplified. There is some support for both scenarios, but the majority of ensemble members look to push the trough to the east, which would be a drying trend for these days with some lingering upslope showers in the mountains and partly sunny and breezy conditions for areas to the south.

AVIATION /04Z TUESDAY THROUGH SATURDAY/
Short Term...Widespread VFR conditions expected into Tue evening. Tue evening and overnight a cold front will approach with scattered SHRA/TSRA along it. Some local MVFR or lower conditions are possible...but these will be mainly confined to the mtns. The most likely TAF sites to experience any flight restrictions would be HIE and LEB.

Long Term...High pressure brings VFR all sites for Wednesday and Thursday. The weather pattern then becomes more unsettled Thursday night into the weekend with multiple rounds of showers possible and increasing potential of flight restrictions. Even outside of precipitation, the southerly flow may lead to fog and IFR stratus during this time.

MARINE
Short Term...Winds will diminish tonight and become southwesterly. Those southwest winds will increase especially the latter half of Tue. SCA conditions are anticipated outside of the bays thru Tue night.

Long Term...SCA conditions likely continue into at least some of the day Wednesday, possibly into the evening across the eastern waters. After that, high pressure keeps conditions under SCA levels Wednesday night through Thurday night. The high shifts east Friday and into the weekend with southerly flow probably increasing to SCA levels at times ahead of the next front/low pressure system that looks to cross through Saturday or Saturday night. West to northwest flow follows for Sunday and Monday with SCA conditions remaining possible.

TIDES/COASTAL FLOODING
Highest astronomical tides on the month occur tonight with a tide of 11.8ft at Portland shortly after midnight. With little wave action and northwest winds becoming southwest...a slight negative storm surge is anticipated. At this time no significant impacts are expected...but it is worth noting that tides will be running within a few inches of flood stage.

GYX WATCHES/WARNINGS/ADVISORIES
ME...None.
NH...None.
MARINE...Small Craft Advisory from 1 PM Tuesday to 8 AM EDT Wednesday for ANZ150-152-154.