Marine Weather Net

Rhode Island Sound Marine Forecast


TODAY

W
WINDS
15 - 20
KNOTS

TONIGHT

SW
WINDS
10 - 15
KNOTS

WED

SW
WINDS
10 - 15
KNOTS

WED NIGHT

SW
WINDS
20 - 25
KNOTS

The Marine Weather Forecast In Detail:
ANZ235 Forecast Issued: 402 AM EDT Tue Mar 19 2024

SMALL CRAFT ADVISORY IN EFFECT UNTIL 11 AM EDT THIS MORNING
Today...W Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 3 To 4 Ft.
Tonight...W Winds 15 To 20 Kt, Becoming Sw 10 To 15 Kt After Midnight. Seas 2 To 4 Ft.
Wed...Sw Winds 10 To 15 Kt, Increasing To 15 To 20 Kt In The Afternoon. Gusts Up To 25 Kt. Seas 3 To 5 Ft.
Wed Night...Sw Winds 20 To 25 Kt, Becoming W 25 To 30 Kt With Gusts Up To 35 Kt After Midnight. Seas 4 To 6 Ft.
Thu...W Winds 25 To 30 Kt With Gusts Up To 35 Kt. Seas 5 To 6 Ft.
Thu Night...Nw Winds 25 To 30 Kt, Diminishing To 20 To 25 Kt After Midnight. Seas 3 To 5 Ft.
Fri...W Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 2 To 4 Ft.
Fri Night...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas Around 2 Ft. A Chance Of Rain.
Sat...Se Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 4 To 6 Ft. Rain Likely. Vsby 1 To 3 Nm.
Sat Night...Nw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 6 To 8 Ft. Rain Likely. Vsby 1 To 3 Nm. 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.
SHARE THIS PAGE:           
Area Forecast Discussion
National Weather Service Boston/Norton MA
332am EDT Tuesday Mar 19 2024

Synopsis
Outside of a few rouge showers it will be largely dry today and through the daylight hours of Wednesday. Gusty wind persists into Wednesday with a brief lull tonight. Scattered rain and snow showers will accompany a cold front passage late Wednesday and Wednesday evening, followed by windy and colder conditions late Wednesday night and Thursday. High pressure builds into the region Friday, then low pressure will likely bring rain Saturday which may begin as a period of accumulating snow across portions of the interior.

Near Term - Until 6pm This Evening
* Noticeably cooler with diurnal CU developing late morning through the afternoon.

A quiet Saint Joseph's Day across southern New England, with no weather concerns for those traveling to their nearest Italian bakery for a zeppole! Mid-level trough will move off shore today with the flow aloft westerly to west/northwesterly. Expecting a breezy west wind to continue through the day, BUFKIT soundings depict a well mixed boundary layer, perhaps mixing to 800mb as the RAP and NAM would suggest. Gusting periodically 20 to 30 mph. As we are tapping into to cooler temperatures aloft, 850mb temperatures are roughly around -10C, which is -5C colder than the what is average for middle of March. Afternoon highs are in the 40s, lower 40s across northern Massachusetts, middle 40s across the coastal plain, urban centers of Boston, Hartford, and Providence are 45F-48F. But, adding in the gusty wind, it will feel as if it were in the 30s.

Similar to Monday, we do expect diurnal CU to develop once again. A rather dry atmosphere, PWATs (Precipitable Waters) less than 1/4" inch will result in a very low chance of a spot sprinkle or flurry. Latest high-res guidance paints a VERY isolated chance, likely due strong mid-level forcing as the mid-level trough pushes off shore. As the probability is low, opt to leave it out of the grids, but rather mention in the

Short Term - 6pm This Evening Through 6pm Wednesday
* Spotty shower possible overnight for far northwest Massachusetts.

* Mild temperatures on Wednesday, spotty shower possible during the day, better chance comes late Wednesday.

Tonight: Increasing cloud cover, wind shifts more southwest with diminishing wind speeds. Spot snow showers are possible across far northwest Massachusetts do to orographic upslope on the west side of the Berkshires. PWATs (Precipitable Waters) are low, but the SLR are around 16:1, perhaps a coating of snow, to an half inch for locations at or above 1500 feet. Lows fall to either side of freezing.

Wednesday: Mid-level warm front moves from south to north during the day, a spot shower or two possible, otherwise dry. PWATs (Precipitable Waters) increase from WAA (Warm Air Advection - the movement of warm air) to 0.3 to 0.5 this is more or less near normal for mid March. With the lack of forcing, do not expect much in the way of showers. The better forcing with the negatively tilted mid-level trough will come in later, Wednesday night with better chance of showers and usher in much cooler conditions. More on that in the long term discussion. Wednesday does feature more gusty wind, this time it is out of the southwest between 25 to 30 mph. High temperatures recover to the upper 40s across the interior to the low 50s for the coastal plain.

Long Term - Wednesday Night Through Monday
Key Points... * Scattered rain and snow showers Wednesday evening * Windy and colder Thursday with diminishing wind Friday * Increasing chances for more significant precipitation Saturday, although uncertainty in track of low pressure remains high

Wednesday night into Friday... Strong shortwave and cold front passage will be accompanied by scattered rain or elevation snow showers which will become focused across eastern New England Wednesday evening. Then front moves offshore before midnight followed by colder and much drier airmass overnight and Thu as PWATs (Precipitable Waters) drop to near 0.10". This will lead to plentiful sunshine Thu but it come with windy conditions. Winds will ramp up in the cold advection overnight Wednesday night with peak of the wind during Thu. WNW gusts to 30-40 mph expected with possible gusts 40-50 mph over the higher elevations and wind advisories may eventually be needed. Chilly airmass as 850 mb temps bottom out at -12 to -15C Thu morning with temps well below normal. Highs Thu will range from the mid 30s higher terrain to lower 40s near the coast, with gusty winds making it feel much colder.

Winds diminish on Friday as high pressure builds in from the west. Continued dry airmass with lots of sunshine and temps remaining below normal with highs upper 30s to low/mid 40s.

Friday night into Monday... Still considerable spread in the deterministic and ensemble guidance regarding potential impacts from a possible coastal storm through the weekend. Looks like there will be an initial surge of warm advection precipitation late Fri night into Sat as southern stream moisture lifts north into SNE along an inverted trough/surface wave. With antecedent cold air initially in place, precipitation may start as snow, especially interior with some accum possible before changing to rain during Sat. While forecast confidence is below normal for Sat, confidence decreases significantly beyond Sat. Complex upper level pattern with uncertainty how northern stream energy interacts with southern stream system. ECMWF (European Centre for Medium-Range Weather Forecasts) and Canadian maintain a split flow with southern stream low remaining to the south into Monday with persistent easterly low level jet and deep moisture plume leading to wet weather and gusty winds lingering into Sun-Mon. GFS (Global Forecast System) shows more phasing with northern and southern stream low pressure impacting region Sat with potentially heavy rainfall, then system moves off to the east with drying conditions Sun-Mon. Due to large spread in the guidance we leaned toward NBM for the Sat-Monday period which offers high probability of precipitation for Sat, then drying out Sun-Mon. But confidence is very low and large forecast adjustments will likely be needed.

Astronomical tides this weekend are low with Boston around 9.5 ft through Mon. However, if ECMWF solution is closer to reality, persistent easterly flow will likely build seas and surge enough for the potential for minor flooding and beach erosion over multiple tide cycles.

Marine
Forecaster Confidence Levels:

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

Today through Wednesday... High Confidence.

Dry conditions today and tonight, increasing rain chances late Wednesday afternoon ahead of an approaching cold front. Continued Small Craft Advisory due to marginal winds and seas. Will sea the near water advisory end by late this morning, with southern outer waters continuing into this evening as seas are 4-5 feet.

Increasing chances gale force winds could arrive as early as Wednesday evening and lasting into the overnight hours.

Outlook /Wednesday Night through Saturday/... Wednesday Night: Low risk for gale force winds with gusts up to 40 kt. Areas of rough seas. Slight chance of rain showers.
Thursday: Moderate risk for gale force winds with gusts up to 40 kt. Rough seas up to 10 ft.

Thursday Night: Moderate risk for gale force winds with gusts up to 40 kt. Areas of rough seas.
Friday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Seas locally approaching 5 ft.
Friday Night: Winds less than 25 kt. Chance of rain.

Saturday: Low risk for gale force winds with gusts up to 30 kt. Areas of rough seas. Rain likely.

Fire Weather

Today... Minimum afternoon relative humidity values drop into the 25 to 35 percent range today, away from the higher terrain of western Massachusetts and northwest Connecticut. Winds are west to northwest gusting of 20 to 25 mph, a few gusts up to 30 mph are anticipated by late morning/early afternoon.

In coordination with our fire weather partners, have held off on issuing another SPS for elevated fire weather concerns.

Thursday... Gusty WNW winds and rather dry airmass will lead to the potential of elevated fire weather concerns again on Thursday. Minimum relative humidity values of 20-40 percent are expected with gusts 30-50 mph.

NOAA Boston MA Office: Watches - Warnings - Advisories
CT...None. MA...None. RI...None.

Marine
Small Craft Advisory until 11am EDT this morning for ANZ231>235-237-251. Small Craft Advisory until 2pm EDT this afternoon for ANZ250. Small Craft Advisory until 8am EDT Wednesday for ANZ254>256.