Marine Weather and Tide Forecast for Marblehead, MA

KEY MESSAGES

- Widespread rain continues this evening and overnight with some urban and poor drainage flooding possible. Rain will be heavy at times southeast MA and RI where flood risk is greatest.

- Unsettled weather continues into this weekend, then cooler and drier conditions arrive next week.

DISCUSSION
KEY MESSAGE 1...Widespread rain continues this evening and overnight with some urban and poor drainage flooding possible. Rain will be heavy at times southeast MA and RI where flood risk is greatest.

Our front has arrived and stalled as expected, now draped generally from New London, CT to Lawrence, MA. This, as a mid level trough digs into the northeast. As it does it will continue to take on a more neutral tilt keeping flow parallel to the front and extending the ongoing training of moderate to heavy rain focused on southeast MA. Impressive dynamics from placement beneath the RRQ of a 100+kt upper jet and a 40-45 kt LLJ will continue to act on copious moisture (PWATs 3+ SD above normal) to drop another 1-3 inches on southeast MA through sunrise Saturday. In addition to the 1-2.5 inches that fell through mid afternoon this had led to some scattered reports of flooding in the Falmouth area and prompted a few Flood Warnings. This fire hose of moisture is progged to continue focusing on the same area through the overnight hours before the front finally moves east as another surface low forms along the front and strengthens over the Gulf of Maine. The column dries quite a bit on Saturday bringing widespread heavy rain to an end, but the upper trough lingers overhead Saturday and Saturday night. This will mean a mix of clouds and sun on Saturday with increasing coverage of scattered showers thanks to increased lapse rates under the cold pool. Temperature-wise the airmass will be starting to moderate from the extreme warmth/humidity of late with dewpoints dropping behind the front (especially late in the day) and highs in the low 60s.

KEY MESSAGE 2...Unsettled weather continues into this weekend, then cooler and drier conditions arrive next week.

In the wake of today's system, surface low pressure develops in the Gulf of Maine Saturday night into Sunday morning. This low shifts off to the north and east through Sunday morning while the core of an upper level trough steadily follows it from the west. This core is expected to move over southern New England over the same time period, and with it, much cooler temperatures aloft. Temperatures at 500 mb dip to around -20C, with some guidance falling to -25C. Closer to the surface, temperatures at 925 mb fall to around 2-4C and temperatures at 850 mb fall to around 0C by early Sunday morning. Once the upper level trough clears off to the north and east, 850 mb temperatures improve slightly to just around 2C. This colder air aloft will be more supportive of highs Sunday into the start of next week falling back to the 50s with cool nights in the 30s and 40s.

NAEFS guidance indicates no significant deviations from the climatological percentiles for temperatures or moisture for the next week, though did note 90th percentile zonal winds aloft Monday into Wednesday across much of the region. Persistent westerly flow with notably breezy conditions Monday and Tuesday is expected. Winds generally stay westerly through much of the week, given the series of fronts expected to move through the region. With the drier conditions (PWATS to around 0.5" and less and dew points back in the 30s and 40s) at the surface, not much in the way of precipitation is expected with these frontal passages; just cooler air. Occasional cloudiness is expected at most with passing moist air aloft.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
Forecaster Confidence Levels...

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

Tonight...High confidence on trends, lower confidence on exact timing and details.

LIFR/IFR in periods of rain, heavy at times across RI and southeast MA terminals. Risk for -TSRA remains towards parts of SE MA and RI through early tonight. As wave of low pressure tracks along the south coast and then exits the canal, winds will shift to the N-NE. Low risk of marginal LLWS as low level southwest jet of 40-45 kt moves across RI and southeast MA.

Saturday...High confidence on trends, lower confidence on exact timing and details.

Slow improvement to MVFR further west towards BDL in the afternoon. Many areas may remain IFR through the day based on the latest guidance. Winds going more NE in the morning shift more towards the NW and WNW in the afternoon and evening hours, and generally remain at or below 10 kt.

Saturday Night...Moderate confidence.

IFR/MVFR ceilings in scattered rain showers overnight. West winds start light and increase through the overnight hours; 10-15 kts with gusts to 20 kt, except for 20-30 kt gusts for Cape and Island terminals.

KBOS Terminal...High confidence in trends, moderate confidence in exact timing and exact details.

KBDL Terminal...High confidence in trends, moderate confidence in timing and exact details.

Outlook /Sunday through Wednesday/...

Sunday: Mainly VFR, with local MVFR possible. Windy with local gusts up to 30 kt.

Sunday Night through Veterans Day: VFR. Breezy.

MARINE
Forecaster Confidence Levels...

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

Through Saturday night...High confidence on trends, lower confidence on exact timing and details.

A cold front remains stalled across eastern New England this evening. A low pressure traverses this front, reaching eastern MA tonight, then moving east across the waters Saturday. Main impacts will be from areas of moderate to heavy rainfall with poor visibility at times. A few thunderstorms are possible as well. Widespread rain comes to an end Saturday morning.

Rough seas expected across the southern coastal waters. A Small Craft Advisory is in effect for those waters. Seas subside some tonight as winds diminish.

Outlook /Sunday through Wednesday/...

Sunday: Strong winds with gusts up to 35 kt. Rough seas up to 10 ft.

Sunday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 9 ft.

Monday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 9 ft. Slight chance of rain.

Monday Night through Tuesday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas.

Tuesday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas.

Veterans Day: Winds less than 25 kt. Seas up to 5 ft.

CLIMATE
Persistent unseasonable warmth will challenge calendar-day record highs and record high minimums across southern New England climate sites.

Daily Record Lows to Watch:

Boston (BOS): Today 65F (2022)

Hartford/Bradley (BDL): Today 64F (2022)

Providence (PVD): Today 64F (2022)

Worcester (ORH): Today 62F (2024)

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...Flood Watch through Saturday morning for MAZ017>023.
RI...Flood Watch through Saturday morning for RIZ001>008.
MARINE...Small Craft Advisory until 1 AM EST Saturday for ANZ255.
Small Craft Advisory until 4 AM EST Saturday for ANZ256.