Rhode Island Sound Marine Forecast
|Today...Nw Winds 15 To 20 Kt With Gusts Up To 30 Kt, Becoming N 10 To 15 Kt With Gusts Up To 20 Kt This Afternoon. Seas 4 To 6 Ft. Light Freezing Spray This Morning.|
|Tonight...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft.|
|Tue...N Winds 10 To 15 Kt, Diminishing To 5 To 10 Kt In The Afternoon. Seas 2 To 4 Ft.|
|Tue Night...N Winds 5 To 10 Kt. Seas Around 2 Ft.|
|Wed And Wed Night...N Winds 5 To 10 Kt. Seas Around 2 Ft.|
|Thu Through Fri Night...Ne Winds 10 To 15 Kt. Seas 2 To 4 Ft. 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.|
Area Forecast Discussion|
National Weather Service Boston/Norton MA
353am EST Monday Jan 20 2020
Dry, but cold weather is on tap for today and Tuesday as high pressure slowly builds in from the west. Temperatures will begin to moderate Wednesday and especially by Thursday/Friday, but dry weather will persist. There is the potential for a coastal storm this weekend, but uncertainty exists in regards to timing and precipitation types.
Near Term - Until 6pm This Evening
Compact upper level shortwave trough evident in water vapor imagery now progressing off the eastern MA coastline. This feature had interacted with an inverted trough/surface theta-e boundary progressing SE from NH/VT overnight, which led to the production of some short- lived scattered flurries/snow showers on its SE progression through Southern New England. This shortwave trough feature is still leading to a generous amount of cloudiness towards Outer Cape Cod, with skies clearing through NW downsloping across most of interior MA, CT into RI. A continued threat for scattered snow showers still remains across the Outer Cape from Provincetown to Hyannis eastward through the rest of the morning per recent HRRR (High-Resolution Rapid Refresh) and the consensus of several CAM solutions. Any accumulations not totalling more than an inch.
Cold and dry air mass advecting in on NW flow related to the passage of the compact trough, with 925 mb temps -11 to -13C forecast across Southern New England today. After a chilly start with current temperatures running in the mid teens to lower 20s, plenty of sun boosts temps into the upper teens to mid/upper 20s, highest across Cape Cod and the Islands into the MA coastal plain. Despite the cold advection, mixing heigheights are forecast to be pretty low. Still expect NW gusts of 20-25 mph in the interior, and in the upper 20s mph towards coastal MA, Cape Cod and the Islands. However as we move through the day, should see less gustiness as mixed layer wind speeds diminish and ridging noses into the region.
Short Term - 6pm This Evening Through 6pm Tuesday
Tonight through Tuesday:
Surface ridge, extending E from a strong 1044 mb high pressure area centered over the Northern U.S. Plains, will remain across much of New England through the short-term forecast period. High pressure weakens/modifies as it moves southeastward towards the central Appalachians by late Tuesday. Cyclonic flow aloft is maintained through the period as well, with some reinforcement of the trough aloft being delivered by a shortwave disturbance which moves quickly southeastward into northern NH through ME late tonight into Tuesday.
All told, this looks to be a continued chilly but also a fairly tranquil stretch of weather. Plenty of sun during the day, and clear/calm conditions at night supporting near optimal radiational cooling and cold low temps. Lingering NW winds around 10-15 mph early tonight will continue to lighten and eventually become light and variable into Tuesday.
Temperatures will be below-average compared to typical late-January climatology. Under good radiational cooling, low temperatures in the single digits across north-central and northwest MA under a light snowpack, with lower teens otherwise common in the interior into the coastal plain. Lows on the Cape and the Islands into the upper teens to low 20s. Highs Tuesday under plentiful sun then rebound back into the 20s.
Long Term - Tuesday Night Through Sunday
Highlights... * Moderating temps begin Wednesday with above normal temps Thu/Fri along with continued dry weather
* Potential coastal storm this weekend would favor more rain than snow along the I-95 corridor but uncertain across the interior
Details... Wednesday through Friday... Large high pressure will remain in control Wed/Thu and Fri. This will maintain dry/tranquil weather, but temperatures will moderate as some upper level ridging builds into southern New England. High temps should recover well into the 30s Wednesday and then into the 40s by Thu/Fri. Weak gradient may allow for sea breeze development, so could be some cooling along the very immediate coast during the afternoon. Regardless, given light winds and above normal temperatures it will feel rather comfortable outside during Thu and Fri afternoons for late January standards.
This Weekend... The long range guidance/ensembles continue to indicate the potential for a coastal storm to impact southern New England sometime this weekend. Given this is still 5 to 6 days in the future, uncertainty exists on potential timing, ptype, and amounts. The one thing we can say is that the antecedent airmass ahead of this potential storm will be relatively mild for January standards. This is a result of a deep Alaskan trough allowing for modified Pacific air across our region. That being said, there does appear to be a surface high pressure located across eastern Canada. Depending on its exact positioning and track of the potential coastal storm, just enough cold air may result in the threat for snow/ice across parts of the interior. While snow can not be ruled out along the coastal plain too, rain would be favored unless the low pressure system would be ideal for winter weather.
So in a nutshell, this potential storm is still 5 to 6 days in the future and not a guarantee the we are impacted. There is some blocking to the north, so this does have the potential to be a slow moving coastal storm. Ptype would favor more rain than snow along the coastal plain, but greater uncertainty further back into the interior.
SCAs (Small Craft Advisories) remain in effect for all waters except Narrangsett Bay. Though NW gusts may briefly increase through mid-morning, should be able to peel away/remove these SCAs (Small Craft Advisories) as winds subside today. Seas over 5 ft will continue on the outer waters through late tonight/early Tuesday AM.
Today: NW winds 15-20 kt with gusts 25-30 kt early, then subsiding to 15-25 kt gusts late today, higher on outer waters. Seas 4-8 ft, highest on the outer eastern/southeast waters, around 1-2 ft nearshore. Few snow showers reducing visibility to around 4-6 mi near/east of Cape Cod. Light freezing spray.
Tonight: NW winds 10-15 kt gusts 15-25 kt early, then subsiding to 20 kt gusts by overnight. Seas 4-6 ft. Good visibility.
Tuesday: NW winds around 10 kt decrease to light NW. Seas decrease to 2-4 ft on offshore waters, around a foot nearshore. Good visibility.
Outlook /Tuesday Night through Friday/... Tuesday Night through Wednesday Night: Winds less than 25 kt.
Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Thursday Night: Winds less than 25 kt. Areas of seas approaching 5 ft.
Friday: Winds less than 25 kt. Seas up to 5 ft.
NOAA Boston MA Office: Watches - Warnings - Advisories
CT...None. MA...None. RI...None.
Small Craft Advisory until 1pm EST this afternoon for ANZ231>234. Small Craft Advisory until 9am EST this morning for ANZ230. Small Craft Advisory until 10am EST this morning for ANZ235- 237. Small Craft Advisory until 6am EST Tuesday for ANZ250-254-255. Small Craft Advisory until 1am EST Tuesday for ANZ251. Small Craft Advisory until 7pm EST this evening for ANZ256.