Marine Weather Net

Rhode Island Sound Marine Forecast


REST OF TONIGHT

N
WINDS
15 - 20
KNOTS

FRI

NW
WINDS
15 - 20
KNOTS

FRI NIGHT

W
WINDS
20 - 25
KNOTS

SAT

W
WINDS
20 - 25
KNOTS

The Marine Weather Forecast In Detail:
ANZ235 Forecast Issued: 101 AM EDT Fri Mar 29 2024

GALE WARNING IN EFFECT FROM 8 AM EDT THIS MORNING THROUGH SATURDAY MORNING
Rest Of Tonight...N Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 4 Ft. Patchy Fog. Rain. Vsby 1 To 3 Nm.
Fri...Nw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 4 Ft. Patchy Fog In The Morning. Rain In The Morning With Vsby 1 To 3 Nm.
Fri Night...W Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft.
Sat...W Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft.
Sat Night...W Winds 15 To 20 Kt With Gusts Up To 25 Kt, Diminishing To 5 To 10 Kt After Midnight. Seas 2 To 4 Ft.
Sun And Sun Night...Nw Winds 10 To 15 Kt With Gusts Up To 25 Kt. Seas 2 To 3 Ft.
Mon...Ne Winds Around 10 Kt. Seas 2 To 3 Ft.
Mon Night...Se Winds Around 10 Kt. Seas Around 2 Ft. A Chance Of Rain.
Tue...E Winds 10 To 15 Kt With Gusts Up To 25 Kt. Seas 2 To 3 Ft. Rain Likely.
Tue Night...E Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 4 To 6 Ft. Rain Likely. Seas Are Reported As Significant Wave Height, Which Is The Average Of The Highest Third Of The Waves. Individual Wave Heights May Be More Than Twice The Significant Wave Height.
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Area Forecast Discussion
National Weather Service Boston/Norton MA
157am EDT Fri Mar 29 2024

Synopsis
Dry but windy and cooler weather overspreads southern New England Friday. However, rain will linger across RI and eastern MA in the morning, possibly into early afternoon for Cape Cod and Nantucket. Partial sunshine develops Friday afternoon, but clouds will be slower to exit Cape and Islands. Sunny Saturday with winds diminishing late in the day. Then a chance for a few showers Saturday night into Sunday morning. Dry weather follows Sunday afternoon along with a mix of sun and clouds and continuing into Monday, with near to above normal temperatures. Very unsettled mid next week perhaps a few chances for some accumulating snow!

Near Term - Through Today
2 AM

Key Points Friday... * Rain may briefly mix with snow before ending...but no impacts * Rain ends this morning, except early afternoon Cape Cod/Nantucket * Partial clearing this afternoon away from the Cape/Islands * Windy with highs in the upper 40s to the middle 50s

Details... Mid level trough taking on a negative tilt early this morning, enhancing forcing for ascent over RI and eastern MA, resulting in widespread rain for this region and moderate at times. Hourly rainfall rates only on the order of 0.10 to 0.20 inches. Fairly modest stratiform rainfall event, thus not expecting too much impact for the morning commute across RI and eastern MA. The Flood Watch continues early this morning for northeast CT, RI and eastern- central MA, but this is mainly for river and Small Stream flooding given all the rain we have had this month, resulting in very little river/stream capacity.

Farther to the west across CT into western MA, NW flow on the backside of the developing offshore cyclone, is advecting drier low level air and resulting in much lighter rains across this area. As for ptype, the NAM remains the most amplified of the models with sufficient column cooling for rain to mix with snow later this morning across eastern MA, before the qpf shield moves offshore by midday or so. However, with surface temps remaining above freezing, any wet snow mixing in at times will have no impact on road conditions.

By midday, rain shield will be exiting offshore with the exception of Cape Cod and Nantucket, where it may wait until 21z as model trends have been more amplified and slower with evolving closed mid level low just east of Cape Cod. Developing comma-head will delay sunshine this afternoon. Partial sunshine should develop midday across western CT/MA then slowly progressing eastward but may wait until then just before sunset across eastern MA.

Given Cold Air Advection and good boundary layer mixing along with downsloping NW winds from strengthening offshore storm, temps will overachieve with highs in the low to mid 50s, a few degs above normal for late March. Although, it will feel much cooler given blustery NW winds 20-30 mph, gusting up to 40 mph at times.

.SHORT TERM /TONIGHT THROUGH 6pm SATURDAY/... 2 AM

Key Messages... * Still quite blustery & cold Fri night with lows in the 30s * Lots of sunshine Sat (inc clouds late) & diminishing winds

Details... Friday night... Sub 980 mb low lifts north through the Canadian Maritimes. This will continue to result in quite blustery conditions to persist with gusts in the 20 to 30 mph range and up to 35 mph or so in spots during the evening. Lows will be seasonable for late March, in the 30s but gusty NW winds will combine to yield wind chills in the 20s.

Saturday... Deep, cold mid level trough moves farther away from SNE, resulting in rising heigheights and warming temps aloft across the region. This will result in abundant sunshine and diminishing winds in the afternoon. After a chilly start to the day, temps will respond to the late March sun along with downsloping NW winds, will push highs into the mid 50s. It will be pleasant in the afternoon given ample sunshine and diminishing winds later in the day. Mid/high clouds arrive late in the day across the western horizon, as next short wave trough approaches.

Long Term - Saturday Night Through Thursday
* Chance for a spot shower Saturday night and Sunday but generally dry through Monday with near to slightly above normal temperatures

* Very unsettled mid week with the potential for two low pressure systems impacting the region Tuesday thru Thursday.

Saturday night through Monday... Low pressure stalls over the Gulf of Maine as ridge builds in from the west, resulting in a rather tight pressure gradient and northwest flow; which generally mixes quite efficiently in a drying column. Fortunately, resulting 925mb LLJ appears to be about 10kt weaker compared to this time yesterday, maxing out between 30-40kt early Saturday, so while blustery conditions will persist into the first half of the weekend, expecting max gusts in the 30 to 35kt range across the highest terrain; below advisory level criteria.

As mentioned, the column dries with PWATs (Precipitable Waters) between 0.2-0.25" on Saturday yielding sunny skies. Weak shortwave approaches from the west Saturday evening, resulting in increasing cloud cover and increasing moisture, as PWATs (Precipitable Waters) climb to ~0.8" across CT and RI between 00-12Z. This shortwave may result in some light rain and snow shower activity, particularly south of the I-90 corridor, but current guidance shows the precipitation shield being "sheared apart" as it dives south of the region. Overall, not expecting a high impact event, but perhaps a couple hundredths of an inch of Quantitative Precipitation Forecast will fall; certainly not enough to snarl weekend plans.

Mid level ridging continues to build into SNE late Sunday and Monday with decreasing cloud cover, particularly across eastern MA and RI. Temps will rebound into the 50s, and perhaps mid 50s, on Monday.

Tuesday and Beyond... The middle of next week looks quite unsettled with the potential for not one but two low pressure systems to impact southern New England. The first comes Tuesday and Wednesday as low pressure moves northeast into SNE. With little to no time between the first and second system, impacts will persist through the day Wednesday into much of the day Thursday as a second low strengthens off the coast of Maine Wednesday night. At present, temperatures look seasonably cold, with highs in the 30s to near 40F, which could support mixed precipitation or even snow north of the Route 2 corridor through the period, acknowledging the forecast will rely heavily on the track of the lows. In any case, with marginal temperatures, 10:1 snow maps will far overestimate the potential for accumulating snow; with the 12Z Canadian's 3 feet across north-central MA being completely out of the question. With that said, ensemble probabilities and positive snow depth change forecasts do paint a picture of accumulating snow as far south as the MA/RI and MA/CT border over the 48 hour period. Only time will tell if Boston sees more accumulating snow in the month of April than March, oof!

Marine
Forecaster Confidence Levels:

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

2 AM

* NW Gales Friday/Fri night

Friday and Saturday...High Confidence.

Low pressure just SE of the 40N/70W benchmark intensifies into a gale center today as it becomes a 980 mb low approaching Nova Scotia late Fri. This will yield NW gales across the MA/RI waters Friday and Friday night. As the low exits thru the maritimes and into eastern Quebec Sat, winds slowly slacken later Sat across MA/RI waters.

Outlook /Saturday Night through Tuesday/... Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain.

Sunday: Winds less than 25 kt.

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

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

Tuesday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas locally approaching 5 ft. Rain likely.

NOAA Boston MA Office: Watches - Warnings - Advisories
CT...Flood Watch until 6am EDT early this morning for CTZ004. MA...Flood Watch until 6am EDT early this morning for MAZ004>007- 012>024-026. RI...Flood Watch until 6am EDT early this morning for RIZ001>007.

Marine
Small Craft Advisory until 8am EDT Saturday for ANZ230-236. Gale Warning from 6am this morning to 11am EDT Saturday for ANZ231-250-251-254>256. Gale Warning from 8am this morning to 11am EDT Saturday for ANZ232>235-237.