Marine Weather and Tide Forecast for Hatfield, MA

NEAR TERM /THROUGH TONIGHT/
We'll see some modification of the airmass overhead today as winds become more southwesterly ahead of tonight's system. The first half of the day will be mostly sunny then mid/high clouds increase through the afternoon as warm advection kicks in. High temperatures should be around 5 or so degrees warmer than yesterday, in the 30s to near 40F.

SHORT TERM /SUNDAY/
A quick moving clipper system passing through northern New England overnight into Sunday will drag a warm front through the northeast resulting in a shield of warm frontal precipitation overnight, generally between 9 pm Saturday (west) and 9 am Sunday (east). Given the overnight timing and the already entrenched colder airmass this precipitation should fall as snow for much of the region, save for Block Island, Martha's Vineyard, and Nantucket. Even Cape Cod could get a coating of snow on the front end before warm SW flow moderates the low levels enough to switch over to rain for portions of RI and southeast MA. Snow amounts shouldn't be too significant, even given the decent lift in the dendritic growth zone per BUFKIT soundings.
Totals will most likely an inch or two, in the interior of MA, northern CT, and northeast MA.

As this system passes by it will induce a strong 45-50 kt LLJ making for a gusty overnight period, especially over southeast MA and over the southern waters. Model soundings indicate mixing down of gusts as strong as 35 to 45 mph with some localized higher amounts possible. A Wind Advisory may be necessary with future updates.
Gusty winds continue on Sunday, gusting 25 to 35 mph across much of the region. Fortunately it won't be bitterly cold, with highs in the mid to upper 40s thanks to the warm SW flow. Sunday the system exits east leaving drier but still breezy conditions, with winds gusting 25 to 35 mph. The biggest change will be the warmer airmass overhead; 925 mb temps increase from -5C on Saturday to +2C on Sunday, resulting in highs in the mid to upper 40s.

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/
Key Messages:

* Unsettled start to the work week with mixed precipitation possible Monday evening into Tuesday morning

* Deepening trough and its associated surface low bring widespread soaking rain Wednesday into Thursday

* Drying out going into the weekend

Sunday night, surface high pressure moves into the region following the exiting clipper system to the north. Winds and cloud cover decrease a bit which will allow temperatures to sink into the 20s across much of the region and the 30s along the coasts. Monday during the day should remain dry before the chance for rain -- and some mixed precipitation across the higher elevations -- arrives.
BUFKIT soundings across central and western MA indicate warm air advection Monday night into Tuesday morning as a warm front is expected to push through, leading to the chance for some pockets of freezing rain. As of now, the chance is still low, but it will be something to continue to monitor. Highs Tuesday are likely to be in the 40s and 50s (similar to Monday) and lows Tuesday are expected to range from the 30s to the 40s.

As the front exits the region, rain will end going into the day Tuesday. A trough digging into the Great Lakes region and its associated surface low approaching from along the east coast will provide yet another chance for rain Wednesday. Deterministic and ensemble guidance continues to be in relatively good agreement regarding this system, and NAEFS indicates specific humidity anomalies close to +3 above the standardized anomaly across southern New England at 925, 850, 700, and 500 mb levels by late Wednesday.
Overall, a widespread soaking rain event is favored, and with temperatures in the 50s during the day, this is likely to be just rain before a cold front pushes in from the west overnight Thursday.
Wednesday night lows sink into the 20s and 30s once again as the aforementioned front and the cold air following it makes its way east. A chance for some snow showers in central and western MA is the result.

High pressure from the central US will begin to build its way into southern New England following Wednesday/Thursday's system, and W to NW flow will usher in colder Canadian air. Thursday highs go back down into the 30s and lower 40s. Thursday night lows are currently forecast to be in the teens once more across much of southern New England with 20s along the coasts.

AVIATION /17Z SATURDAY THROUGH WEDNESDAY/
Forecast Confidence Levels:

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

18Z TAF Update

Trough 00Z...High Confidence

Increasing mid-level cloudiness after 21Z with steady WNW winds becoming light out of the southwest after 21-22Z.

Tonight...Moderate Confidence

VFR through about 06Z with southwest winds from 5 to 10 knots. A period of light snow is expected between roughly 04 and 10Z.
Accumulations from a dusting to an inch are possible as well as a period of MVFR ceilings. Light snow showers should come to an end in the 09-11Z time frame with any MVFR ceilings improving to VFR. Gusty southwest winds up to 25 knots develop after 09Z.

Tomorrow...High Confidence

VFR. Breezy southwest winds around 12 knots with gusts to 20-25 knots possible.

Tomorrow Night...High Confidence

VFR. Light west winds becoming light/variable.

KBOS Terminal...Moderate Confidence

Expect light snow to begin around 06Z but as early as 05Z. A period of MVFR ceilings will be possible with the light snow showers between 06 and 09Z. High confidence in improvements to VFR by 12Z and thereafter. Winds strengthen after 09Z with some gusts up to 25 knots possible through about 18Z tomorrow afternoon.

KBDL Terminal...Moderate Confidence

Light snow beginning around 04Z and lasting through about 08-09Z. Some MVFR ceilings/vsbys may be possible during this time, but generally expecting cloud bases from 040-050 feet.
VFR conditions tomorrow with steady southwest winds.

Outlook /Sunday Night through Wednesday/...

Sunday Night: VFR. Breezy.

Monday: Mainly VFR, with areas MVFR possible. Chance RA.

Monday Night: Mainly IFR, with areas MVFR possible. RA.

Tuesday: MVFR/IFR conditions possible. Chance RA.

Tuesday Night: MVFR/IFR conditions possible. Breezy. RA.

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

MARINE
Forecaster Confidence Levels:

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

Today: High confidence.

W winds around 15-20 kt with seas 3-5 ft will continue to decrease to below SCA levels.

Tonight: Moderate confidence.

Increasing SW winds to at least around 15-25 kt with seas building to 4-6 ft, perhaps near 7 ft by daybreak Sunday. Marine headlines are likely to be needed in this period, certainly Small Craft Advisory levels but there is the potential for the need of Gale Warnings. Possible reduction in visby from light snow over the northern waters, and little if any southern waters.

Sunday: High confidence.

W winds 25-35 kt to start with gusts 30-35 kt possible. Winds decrease in the afternoon. Seas 6-10 ft on the southern waters with 3-5 ft on the eastern waters.

Outlook /Sunday Night through Wednesday/...

Sunday Night: Winds less than 25 kt. Local rough seas.

Monday: Winds less than 25 kt. Chance of rain.

Monday Night: Winds less than 25 kt. Seas up to 5 ft. Rain.

Tuesday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain.

Tuesday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Rain.

Wednesday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 12 ft. Rain. Areas of visibility 1 to 3 nm.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Gale Watch from late tonight through Sunday afternoon for ANZ235-237-250-254>256.
Small Craft Advisory until 1 PM EST this afternoon for ANZ250- 254>256.