Marine Weather and Tide Forecast for West Falmouth, MA

NEAR TERM /THROUGH TONIGHT/
Key Messages:

* Heavy rain and nuisance street flooding will impact the afternoon and evening commute across eastern MA and portions of RI

* NE wind gusts of 40-50+ mph along the coast, especially Cape and Islands, with pockets of minor coastal flooding during the evening high tide

* The peak of the rain and wind will gradually taper off late this evening and overnight

Coastal low south of New Eng slowly tracks northward near Nantucket this evening before lifting into the Gulf of Maine toward daybreak.
The peak of the heavy rain and wind will occur late afternoon and evening as the low level jet axis lifts north across eastern New Eng. Strong low level convergence at the nose of the jet combined with favorable mid level low track will bring a period of heavy rainfall to eastern MA which may extend into RI. Cloud tops are cooling to the south and expect heavy rain to blossom as it lifts north across eastern New Eng later this afternoon. There is also some elevated instability at the edge of the dry slot which will support a few t-storms over Cape/Islands and possibly eastern MA.

Strong signal in the HRRR with high probs (up to 70 percent) of > 1" in successive 3 hour periods focused across eastern MA. Potential for 1-2 inches of rainfall in a 6 hour period with locally higher amounts. Timing of heaviest rainfall will be around 4 pm to midnight which will impact the evening commute with areas of urban and poor drainage street flooding. Strongest winds will be focused over Cape/Islands with peak gusts to 45-55 mph late afternoon and evening, with strong gusts lifting north along the eastern MA coast through midnight with gusts 35-45 mph.

Rain will begin to diminish after midnight as the low level jet lifts to the north but periods of rain will continue overnight across eastern New Eng, along with gusty N winds along the coast.
Interesting to note as the boundary cools with 925 mb temps hovering near 0C, there could be some snowflakes mixed in over the Berkshires this evening.

A Coastal Flood Advisory continues along the coast for low-end minor flooding potential with the evening high tide, when some erosion and minor splashover is possible. Fortunately, astronomical tides are on the lower side, which saves us from much bigger problems that would have arisen.

SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/
Friday and Friday night...

Some improvement expected as the low pres slowly lifts north from the Gulf of Maine, but still chilly and unsettled as mid level low lingers across northern New Eng with deep moisture in place. Expect lots of clouds with scattered showers during the day and persisting into Fri night. While it will be milder on Fri, daytime temps will remain well below normal in the 50s. Breezy N winds along the eastern MA coast in the morning then diminishing in the afternoon.

LONG TERM /SATURDAY THROUGH THURSDAY/
Key Messages:

* Still cool with a few scattered showers Saturday.

* Warmer temps and dry weather will mean Memorial Day is good for outdoor activities.

* Wet weather returns around mid-week but timing details uncertain.

A slow but steady improvement in our weather conditions continues on Saturday and through the holiday weekend as Thursday's storm slowly moves away, into the Canadian maritimes by Saturday. This places southern New England in cool northwest flow while the trough lingers in our vicinity. This upper level cyclonic flow will result in a mostly cloudy day (but with breaks of sun, especially later) with scattered showers. However, not expecting a washout by any means; simply a cooler day in the low 60s with some passing showers.

Sunday into Memorial Day that improving trend continues as temperatures climb (upper 60s Sun, low 70s by Mon); however the trough is very slow to exit so a weak disturbance or two rounding the broader trough may bring a few widely scattered showers, especially on Sunday. Even so, most will be dry and we'll see more sun. Memorial Day is looking like the pick of the weekend with the warmest temperatures and least chance of rain as mid level ridging finally shifts toward the region.

As we move into Tuesday dry weather continues coinciding with the warmest day in a while as the ridge axis moves overhead. Beyond that another trough takes aim at the northeast increasing rain chances for mid week, but confidence in timing and details is low at this point given model uncertainty.

AVIATION /18Z THURSDAY THROUGH TUESDAY/
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

18z TAFs: Overall high confidence in trends, but some uncertainty in timing.

MVFR conditions in rain and fog will give way to more widespread IFR conditions as we head through late afternoon and into tonight. Potential for embedded TS near the south coast, especially on Cape Cod and the Islands through late afternoon.
E/NE winds gust to 30kt inland and to 40-45kt along coast. In addition, LLWS expected near ACK due to 40-50kt winds at 020.

Slow improvement late tonight into Friday as rain ends from southwest to northeast, but MVFR/IFR ceilings are likely to persist.

BOS TAF...High confidence.

BDL TAF...High confidence.

Outlook /Saturday through Tuesday/...

Saturday: Mainly VFR, with local IFR possible. Breezy. Slight chance SHRA.

Saturday Night through Sunday: Mainly VFR, with local MVFR possible.

Sunday Night: VFR.

Memorial Day: VFR. Slight chance SHRA.

Monday Night: VFR.

Tuesday: VFR. Slight chance SHRA.

MARINE
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

Through Friday night: High confidence.

Peak of the wind will occur through this evening over waters east of Cape Cod with gusts 35-45 kt, then lifting N over NE MA waters with NE winds becoming N. Winds gradually diminish overnight but marginal northerly gales will persist over NE MA waters through the night. Seas peak at 10-15 ft over eastern MA outer waters this evening, then slowly subsiding Fri into Fri night.

A period of heavy rain through this evening with a few t-storms possible then rain diminishing to scattered showers late tonight and Fri.

Outlook /Saturday through Tuesday/...

Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers.

Saturday Night: Winds less than 25 kt. Seas locally approaching 5 ft.

Sunday through Monday Night: Winds less than 25 kt.

Tuesday: Winds less than 25 kt. Slight chance of rain showers.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...Wind Advisory until 11 PM EDT this evening for MAZ007-015-016- 019-022>024.
Coastal Flood Advisory from 6 PM to 11 PM EDT this evening for MAZ007-015-016-019-022>024.
Coastal Flood Advisory until 7 PM EDT this evening for MAZ020- 021.
RI...Coastal Flood Advisory until 7 PM EDT this evening for RIZ006>008.
MARINE...Gale Warning until 6 AM EDT Friday for ANZ230.
Gale Warning until 2 AM EDT Friday for ANZ231>237-254>256.
Gale Warning until 8 AM EDT Friday for ANZ250-251.