Marine Weather and Tide Forecast for Southwest Harbor, ME

NEAR TERM /THROUGH SUNDAY/
An upper level disturbance exits the region this evening.
Vertically stacked surface/upper lows then approach from the west late tonight. An isolated thunderstorm is possible across the north early this evening. Otherwise, expect numerous/widespread showers across the region tonight. Will also have fog tonight, most extensive across Downeast areas. A Dense Fog Advisory could eventually be needed across Downeast areas. The vertically stacked system will begin to cross the region Sunday with numerous/widespread showers along with patchy/areas of fog. Low temperatures tonight will range from around 50 to the lower 50s across much of the forecast area, with mid to upper 40s along the Downeast coast. High temperatures Sunday will range from around 60 to the lower 60s across much of the forecast area, with mid 50s to around 60 along the Downeast coast.

SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/
Vertically stacked occluded low pressure system moves out of Maine by Sunday night, moving out to Nova Scotia on Monday night. Cold air advection behind this system, which keeps temperatures on the cool side during the short term period.
Rain showers overnight, with some areas of fog over coastal areas, and patchy fog more inland, both of which may linger into the morning hours. Highest rainfall rates in northern counties, but throughout the short term period, not looking at more than half an inch of rain of additional rainfall from what previously fell over the weekend. Overnight lows in the upper 40s/low 50s. Plenty of cloud cover forecast with ample moisture throughout the atmosphere, keeping highs on Monday in the upper 40s to mid 50s. Overnight lows on Monday night in the lower-40s.

Brief period of upper-level ridging Tuesday into Wednesday, bringing in some dry air in the mid-levels, which helps rain showers begin to diminish. Skies become partially cloudy by Tuesday afternoon, with highs in the mid-50s.

LONG TERM /TUESDAY THROUGH SATURDAY/
Mid-week brings a brief period of ridging Wednesday, that moves out by Wednesday night as the next vertically stacked low pressure system from our west moves into New England. Two low pressure centers begin circle around each other right over Maine. Current guidance is struggling with the placement of the low center as it moves around, with the GFS staying more to the north of Maine, while the EURO has the low more along the coastline. Either way, as a result, rain showers forecast for the rest of the week next week. Chance of rain showers continuing into the weekend. Highs stay relatively cool, in the 50s throughout the end of the week. Lows in the 30s/40s.

AVIATION /21Z SATURDAY THROUGH THURSDAY/
NEAR TERM: Generally IFR/LIFR tonight through Sunday. Occasional VLIFR tonight through early Sunday, mostly Downeast. An isolated thunderstorm possible across northern areas early this evening. Otherwise, numerous/widespread showers tonight through Sunday. Patchy/areas of fog tonight through Sunday. Widespread dense fog also possible Downeast tonight. Southeast winds 5 to 10 knots, becoming variable tonight. Variable winds 5 to 10 knots Sunday.

SHORT TERM: Sunday night.. MVFR/IFR conditions due to rain showers, and a potential for low cloud ceilings. Fog at southern terminals possible. Winds from the N/NW at 5-10 kts. Gusts up to 20 kt possible.

Monday-Monday night.. MVFR conditions due to rain showers.
Winds from the N/ NW at 5-10 kts with gusts up to 20 kts possible.

Tuesday...VFR/MVFR due to rain showers. Winds from the N/NE at 5-10 kts. Gusts up to 20 kt possible.

Tuesday night–Wednesday..VFR conditions. Winds from the NE, shifting to the E by Wednesday at 5-10 kts.

Wednesday night.. MVFR conditions due to rain showers. Winds from the E at 5-10 kts.

Thursday... MVFR due to rain showers. Winds from the E at 5-10 kts, with gusts up to 20kt possible.

MARINE
NEAR TERM: Winds/seas below small craft advisory levels tonight through Sunday. Widespread/numerous showers tonight, then scattered showers Sunday. Fog tonight through Sunday.

SHORT TERM: Seas and winds stay below Small Craft Advisory criteria throughout Monday. Winds have a chance to gust up to low end small craft winds on Tuesday over the outer waters.
Potential for some areas of fog to develop over the waters Sunday night into Monday morning. Rain showers throughout the weekend, into the middle of next week. Outer waters stay at or below 4 ft in the short term period. Intra-coastal waters stay at or below 3ft. Winds on Sunday night from the SW, shifting to the NW by Monday. Winds from the N Monday night, and then shift NE by Tuesday.

CAR WATCHES/WARNINGS/ADVISORIES
ME...None.
MARINE...None.