Marine Weather and Tide Forecast for Rockport, MA

NEAR TERM /THROUGH TONIGHT/

Key Messages...

* Dry to start Monday then rain and some high elevation icing move in late Monday/Monday night

Expect a quiet start to the work week as weak mid level ridging follows the exiting trough axis during the first part of the day. As Monday wears on though we'll see increasingly thick cloudcover out ahead of our next storm system. At the synoptic scale we have another low developing over the western Great Lakes with a secondary low induced over southern New England. As the associated shortwave passes this evening it will interact with a deep plume of moisture (PWATs near 1") and warm SW flow to induce widespread precipitation over western MA/CT by early afternoon and eastern MA by evening. The warm advection which brings relatively mild temps on Monday (highs in the mid 30s to mid 40s) will mean rain for the vast majority of SNE. The exception may be the highest elevations of the Berkshires and Worcester Hills where pockets of freezing rain/light ice accumulations are possible. Given the placement of a high pressure over Quebec subfreezing air may linger at the surface while soundings indicate a decent warm nose at 850 mb. A Winter Weather Advisory has been issued for the northern slopes of the Berkshires and northern Worcester Hills where a coating of ice may make for hazardous driving conditions by the Tuesday morning commute.
Elsewhere a decent amount of rainfall is expected before majority of the precip exits by midnight; odds favor a quarter to half inch of rain.



SHORT TERM /TUESDAY/

Tuesday we'll be between systems with continued moist low level easterly flow keeping low clouds socked in. Even lacking any synoptic forcing saturated low level onshore flow may lead to areas of drizzle and perhaps even some freezing drizzle in the high elevation interior, though confidence in icing is low at this point.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
Key Messages:

* Rain starts to move in late Tuesday night/early Wednesday morning and sticks around through Thursday morning

* Winds pick up from the south as storm moves in

* Drying out during the day Thursday before another chance for unsettled weather Sunday

There is high confidence in the main synoptic pattern early in this period. Following a shortwave Tuesday morning, more rain is expected to move in by early Wednesday morning with the arrival of a surface low coming in from the Mid-Atlantic region. Rain should move out of the region Thursday. Temperatures aloft continue to be warmer than normal; 850 mb temps across the ensembles and the deterministic guidance are likely to be up to +10C by Wednesday afternoon, which is a good signal for the warmer than normal highs in the forecast; some spots in SE MA could reach close to 65F. Winds are also expected to pick up from the south as the jet associated with this system moves over southern New England.

In terms of rainfall amounts, there is still some uncertainty as to where the highest amounts will be. GEFS and GEPS have the highest probs for greater than 2" of rain over the event in western MA down into CT while the ENS shifts that chance over towards the Cape. The NBM has probs up to 88% for greater than 2" across RI up into Boston over a 48 hour span and an 81% chance for that same criteria over in the eastern slopes of the Berkshires. There is also a 50% chance for amounts greater than 3" over eastern RI in a 48 hour span. Suffice to say, there is still a range of where the most rain could fall over the course of this event. Some localized flooding could be an issue depending on the presence of some partially frozen ground, but the extent of any flooding impacts is still unknown this far ahead of the event.

As the low moves out and the rain comes to an end, cold air following a cold front is expected to make its way into the region.
Preceding this cold front, the forcing from it could lead to some rumbles of thunder from CT through RI and up into eastern MA and the Cape. Some snowflakes could fall across western and central MA as this colder air begins its progression eastward, but not much accumulation over a coating looks favored at this time.

Surface high pressure moves in, drying out the region going into Friday and the weekend. Temperatures are also expected to drop once again -- especially Thursday night -- and return to more seasonable levels.



AVIATION /09Z MONDAY THROUGH FRIDAY/
Forecast Confidence Levels:

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

06Z update...

Today...High Confidence.

Winds light and variable. VFR to start then lowering to MVFR/IFR by evening in RA.

Tonight... High Confidence.

IFR with embedded IFR in RA/-RA through about 06Z. Low ceilings persist through Tuesday morning with easterly winds becoming north/NNW by 12Z Tuesday.

Tuesday...High Confidence.

IFR/MVFR cigs with light winds, slight chance of RA.

KBOS Terminal...High Confidence.

KBDL Terminal...High Confidence.

Outlook /Tuesday Night through Friday/...

Tuesday Night: Mainly IFR, with areas MVFR possible. Breezy.
RA.

Wednesday: Mainly IFR, with areas MVFR possible. Windy with gusts up to 35 kt. RA, isolated TSRA.

Wednesday Night: MVFR/IFR conditions possible. Strong winds with local gusts up to 40 kt. RA.

Thursday: VFR. Breezy. Slight chance RA, slight chance SN.

Thursday Night: VFR. Breezy.

Friday: VFR.

MARINE
Forecaster Confidence Levels:

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

Today and Tonight...High confidence.

Winds increase out of the east southeast this afternoon ahead of an approaching low pressure system that will bring rain to the coastal waters this afternoon and evening. Gusts to 30 kt are possible on the outer eastern waters. The surface low pressure center moves over the coastal waters tonight which will result in variable wind direction with northeast winds over the eastern zones and west winds over the southern waters. Seas may increase to near SCY levels on outer waters.

Tuesday...High confidence.

NE winds on the eastern waters with SW winds on the southern waters early, then all shifting to the SE in the afternoon. Seas 3-4 ft.

Outlook /Tuesday Night through Friday/...

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

Wednesday: Low risk for gale force winds with gusts up to 40 kt. Rough seas up to 14 ft. Rain, isolated thunderstorms.
Local visibility 1 to 3 nm.

Wednesday Night: Strong winds with gusts up to 40 kt. Rough seas up to 18 ft. Rain. Areas of visibility 1 to 3 nm.

Thursday: Strong winds with gusts up to 30 kt. Rough seas up to 14 ft. Chance of rain.

Thursday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 11 ft. Slight chance of rain.

Friday: Winds less than 25 kt. Local rough seas.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...Winter Weather Advisory from 3 PM this afternoon to 10 AM EST Tuesday for MAZ002-004-008-026.
RI...None.
MARINE...Small Craft Advisory until 7 AM EST this morning for ANZ254>256.