Marine Weather and Tide Forecast for East Sandwich, MA

NEAR TERM /UNTIL 6 AM MONDAY MORNING/
Key Messages:

* Rain pushes northward into region late afternoon-early this evening. Few rumbles of thunder possible.

* Overcast, generally dreary tonight with mist/drizzle after main batch of rain exits.

Details...

SPC mesoanalysis shows the warm front pushing into the south coast and Cape/Islands. Radar shows showers moving northward across southern New England with more widespread rain just offshore of the south coast. Some with embedded convective showers/tstorms.
Showers are expected to increase over the next several hours from south to north as the warm front moves north. With this batch of rain, the highest coverage of showers will be across eastern southern New England. Marginal elevated instability will accompany the front which has been shown in the latest mesoanalysis just south of the region. This favor convective showers with briefly higher rain rates and perhaps a rumble of thunder. This potential will be more favored across the south coast and southeast MA.

The surface low and warm front will continue to lift north into New England early tonight with flow becoming southerly on the backside. As the better forcing and deeper moisture exit, this will put an end to the rain/showers. Model soundings indicate drying in the layers aloft overnight; however, the warm/moist advection will keep the lower layer saturated favoring areas of drizzle as well as some fog. Temperatures tonight will stay on the mild side given the warm advection and clouds with temperatures staying in the 50s for many areas and upper 40s for northern MA and higher elevations.

SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/
Key Messages:

* Overcast but a mild start to Monday morning with temps in the mid/upper 50s.

* Strong cold front moves through from west to east this morning through late afternoon. Brings another round of rain ahead of front.

* Sharply falling temperatures behind the front. Falling into 20s/30s in western MA/CT by 10 PM.

Details:

Monday and Monday Night:

The morning will start off mild, drizzly, overcast with the high temperatures of the day taking place (50s) and by early Tuesday morning temperatures will likely have dropped into the 20s and 30s. Quite a change! So what is to blame? An amplified trough will push eastward across the Great Lakes and mid-atlantic states on Monday, eventually pushing in cold temperatures behind a cold front. Models still appear to struggling with the timing of the front and how quickly temperatures crash behind it. A mean of high-resolution guidance moves the front through Monday morning/early PM across western southern New England and through eastern portions of southern New England in the afternoon/early evening. A line of showers/rain will move across ahead of the front.
Behind the front/rain, conditions will improve as dry air aloft works in toward the evening. Temperatures continue to crash as a cold airmass works in with readings falling into the mid-upper 20s for most, with low 20s possible for the higher elevations even despite elevated west winds behind the front. Coastal areas fall into the 30s with breezier conditions (Gusts 20-30 mph)
More wind to come Tuesday

LONG TERM /TUESDAY THROUGH SUNDAY/
Key Messages...

* Gusty, biting wind expected on Tuesday as high temperatures in the upper 30s and low 40s will feel more like the upper 20s and low 30s.

* A few lingering show showers possible over the Berkshires early Tuesday.

* Mostly dry and blustery at times Wed through Sun.

Tuesday features much below normal temperatures with even colder wind chill values. This comes courtesy of a deep upper trough that digs into the northeast Tue-Wed the axis of which will be crossing SNE Tue. The unusually cold airmass which settles overhead (850 mb temps down to -10C) leads to temperatures not making it out of the upper 20s and low 30s in Tuesday's post frontal airmass. The cold advection pattern results in a very well mixed boundary layer, tapping into a 40-50 kt 850 mb jet; model soundings suggest we'll mix down widespread gusts 30 to 40 mph with potential for scattered gusts up to 45 mph. This will make temps feel more like the upper 20s (high elevations) to low 30s. Tuesday is mostly dry as the column rapidly desaturated behind the front, but some orographically enhanced snow flurries/showers are possible especially the first half of the day with some low level moisture streaming off the Great Lakes. Expect a mix of clouds and sun.

Wednesday through at least Friday we'll feel the influence of a lingering trough over the northeast keeping temperatures cooler than average generally in the upper 40s. A few weak disturbances round the trough leading mainly to some orographic rain/snow showers and ocean effect showers offshore, but the column remains largely dry which should prevent any widespread precipitation for the week and into the weekend as a brief ridge approaches around the weekend.

AVIATION /00Z MONDAY THROUGH FRIDAY/
Forecaster Confidence Levels...

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

00Z TAF Update:

Tonight: High confidence in trends but moderate on timing.

Warm front lifts north from 22-02z from south to north.
Categories drop further with IFR-LIFR levels with FG/BR and -DZ.
Winds turn toward SE/S overnight dropping in speed after 00z.
Period of wind shear for east/southeast terminals 00-06z 30-40 kts.

Monday: Moderate confidence.

IFR-LIFR to start. Another batch of rain moves through ahead of the cold front generally from west to east. Rain likely arrives 10-12z across the western terminals and closer to 14-16 further east. Frontal passage 15-22z with ceilings quickly improving behind it. Windshift to W around 10-12 kt with frontal passage.

KBOS Terminal...Moderate confidence in TAF.
Ceilings bouncing between MVFR and VFR 18-20z before showers arrive (20-22z). Ceilings dropping toward IFR 22-00z. Showers exit by 02z with -DZ and BR/FG overnight. IFR/LIFR conditions.
Wind shear possible 00-06z. Winds SE/SSE 8-10 kts overnight.
Another round of showers arrive 14-16z Monday. FROPA 18-22z with improving ceilings behind it.

KBDL Terminal...Moderate confidence in TAF.

Outlook /Tuesday through Friday/...

Veterans Day through Tuesday Night: VFR. Windy with gusts up to 35 kt.

Wednesday: Mainly VFR, with areas MVFR possible. Windy with areas of gusts up to 30 kt. Slight chance RA.

Wednesday Night through Thursday: Mainly VFR, with local MVFR possible. Breezy.

Thursday Night through Friday: VFR. Breezy.

MARINE
Forecaster Confidence Levels...

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

Key Messages:

* SCA winds/seas this afternoon/tonight. Showers on all waters this afternoon-evening, with low risk for thunder over the south. Mist/fog could reduce visby on the waters tonight.

* Sharp cold front late in the day Monday.

* Gale-force westerly gusts looking likely for Tue, perhaps into early Wed.

SCAs continue into 12z Monday. Seas 4-6 ft offshore and winds around 25 kts. Winds decrease after midnight, but seas for outer water 3-5 ft. Rain through early tonight with possible mist/fog and drizzle after main batch of rain moves out. Could reduce visbys on waters tonight.

Light SE to S winds early on Mon until frontal passage.
Windshift to W Mon late aftn with gusts increasing into the SCA to near-gale levels Mon night. Gale Watch has been issued for that period. Should likely be upgraded to Gale Warning.

Outlook /Tuesday through Friday/...

Veterans Day: Moderate risk for gale force winds with gusts up to 40 kt. Areas of rough seas. Slight chance of rain.

Tuesday Night: Moderate risk for gale force winds with gusts up to 40 kt. Rough seas up to 14 ft.

Wednesday: Strong winds with gusts up to 35 kt. Rough seas up to 13 ft. Slight chance of rain.

Wednesday Night: Strong winds with gusts up to 35 kt. Areas of rough seas. Slight chance of rain.

Thursday: Moderate risk for Small Craft Advisory winds with local gusts up to 30 kt. Areas of rough seas. Slight chance of rain.

Thursday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Slight chance of rain.

Friday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Slight chance of rain.

TIDES/COASTAL FLOODING
Astronomical tides are still running high coming out of the full moon from late in the week, but should continue to fall into Monday. Continuing to monitor the high tides Monday morning at Nantucket for possible minor coastal flooding, with Stevens Institute supporting about a 1 ft storm surge. However, Stevens Institute guidance keeps means borderline minor flood stage for Nantucket. The "reasonable worst case" indicates there is potential for Nantucket to reach minor flood stage Monday. Since it is so borderline, we will hold off for now on any headlines, but can't rule out a little splash over during the high tide tomorrow.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 AM EST Monday for ANZ230>235-237- 250-251-254>256.
Gale Watch from Tuesday morning through Wednesday morning for ANZ231>235-237-250-251-254>256.