Cape Cod Bay Alt Marine Forecast
20 - 25
15 - 20
10 - 15
10 - 15
20 - 25
20 - 25
|This Afternoon...Nw Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft.|
|Tonight...Nw Winds 15 To 20 Kt, Diminishing To 10 To 15 Kt After Midnight. Gusts Up To 25 Kt. Seas 2 To 4 Ft.|
|Fri...W Winds 5 To 10 Kt, Becoming Sw 10 To 15 Kt With Gusts Up To 20 Kt In The Afternoon. Seas Around 2 Ft. A Chance Of Rain.|
|Fri Night...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft. Rain. Vsby 1 To 3 Nm.|
|Sat...S Winds 20 To 25 Kt, Becoming Sw 25 To 30 Kt In The Afternoon. Seas 3 To 5 Ft. Rain. Vsby 1 To 3 Nm.|
|Sat Night...Sw Winds 20 To 25 Kt, Becoming W 15 To 20 Kt After Midnight. Gusts Up To 35 Kt. Seas 4 To 6 Ft. Rain Likely. Vsby 1 To 3 Nm.|
|Sun...Nw Winds 20 To 25 Kt With Gusts Up To 35 Kt. Seas 4 To 6 Ft.|
|Sun Night And Mon...Nw Winds 10 To 15 Kt, Becoming Sw 15 To 20 Kt. Gusts Up To 30 Kt. Seas 2 To 4 Ft.|
|Mon Night...Sw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 5 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
927am EDT Thu Mar 30 2023
Dry but chilly & blustery weather continues through the afternoon. High pressure provides dry weather tonight, along with diminishing winds but chilly temperatures. Friday begins dry, but an approaching warm front brings rain to the region during the afternoon, possibly starting as a wintry mix across the high terrain of Massachusetts. Robust system to bring widespread rain and gusty wind along with the chance of a thunderstorm or two Saturday afternoon. Despite the soggy weather Saturday afternoon is warm, but will be short- lived with the passage of a strong cold front Saturday evening. Dry, blustery, and cooler for Sunday.
Near Term - Until 6pm This Evening
* Blustery & Chilly into the afternoon with highs 35 to 40 in the high terrain...to between 40-45 elsewhere
Previous forecast is on track. Post-frontal airmass will result in high temps roughly 10 degrees below normal for this time of year. 850T near -12C will be offset somewhat by plenty of that strong late March sunshine. Nonetheless...highs should be held into the 35 to 40 degree range in the high terrain and between 40 and 45 elsewhere. Northwest wind gusts of 25 to 35 mph will make it feel even chillier. Wind chill values will only recover into the lower to middle 30s this afternoon.
Short Term - 6pm This Evening Through 6pm Friday
* Diminishing winds tonight, dry but cold * Dry Friday morning, then rain likely in the afternoon, especially northern MA
Tonight... Dry NW flow aloft and with surface ridge advecting into the region, winds diminish. Dry and cold airmass over the region combined with diminishing winds and initially clear conditions, will promote temps to fall fairly quickly during the evening hours. Temps may level off second half of the night, as mid/high clouds stream across the area. Lows mainly in the mid to upper 20s, except low 30s for the outer Cape and Islands, including downtown Boston.
Friday... Ridging provides dry weather Fri morning along with light winds. Although fast flow aloft will yielding increasing clouds as moisture from upstream trough races eastward. 00z models have trended faster with precipitation chances, with rain likely overspreading the area during the afternoon from west to east. Highest probability of precipitation across northern MA. Ptype will be rain, however there could be enough cold air leftover via evaporational cooling, for precipitation to begin as a period of snow or mixed precipitation across northern Worcester county and the Berkshires. Highs Fri in the 40s, but then cooling thru the 40s and into the mid and upper 30s across the high terrain as precipitation shield overspreads the region. Light southwest winds become SSE in the afternoon.
Long Term - Friday Night Through Wednesday
400am Update: Highlights:
* Robust system to bring widespread rain and gusty wind along with the chance of a thunderstorm or two Saturday afternoon.
* Despite the soggy weather Saturday afternoon is warm, but will be short-lived with the passage of a strong cold front Saturday evening.
* Dry, blustery, and cooler for Sunday.
Friday Night... Warm front lifts north of the CWA (County Warning Area) and advects a warm/moist airmass into southern New England. The southwest flow ushers anomolous vales of PWATs, greater than 250 percent of normal. Scattered rain does become widespread throughout the overnight hours. Global guidance does show a lull in the activity around dawn on Saturday, likely do to the better forcing shifting east. Though do not expect the lull to last more than a couple of hours. Overnight temperatures will warm and not follow the typical diurnal curve thanks to WAA, temperatures climb throughout the 40s. Wind overnight are out of the south/southwest at 10 to 15 MPH, occasional gust 25 MPH.
Saturday and Saturday Night... Periods of rain continue throughout the morning into the early afternoon, after a brief early morning lull. Our focus is then pulled towards the mid-afternoon with the possibility of an isolated thunderstorm or two. Global guidance highligheights a dry slot Saturday afternoon, which could clear enough clouds out to build surface instability. Forecast sounding at BDL show steepening lapse rates, around 8C/km for the surface to 500mb. MUCAPE builds to 500 units, with 50 knots of effective shear. Because of this opt to continue the mention of thunder in the forecast grids Saturday afternoon. Despite the soggy weather the WAA (Warm Air Advection - the movement of warm air) allows temperatures to reach the low and mid-60s. In addition to the rain/storms, a LLJ will bring gusty south/southwest winds 20 to 30 MPH, potentially as high 35 to 40 MPH along the south coast of Rhode Island and Massachusetts.
Cold front moves across the CWA from west to east Saturday evening with improving conditions during the overnight. Outside of a few post frontal rain or elevated snow showers much of the region dries out after midnight. Wind shift to the northwest, still gusting between 20 and 30 MPH, allows for cold air advection, temperatures return the the low and mid-30s overnight.
Sunday into Early Next Week
Ending the weekend on a quiet and cooler note. Behind the cold front on Sunday we have northwest flow which advects a dry airmass into the region. Cooling aloft will lead to a cooler, albeit near normal temperatures for Sunday afternoon in the mid to upper-40s. Surface high pressure expands and moves east Sunday into Monday. WAA aloft on Monday will translate to slightly above normal highs in the mid to upper-50s. Next chance for precipitation possible late Monday into Tuesday with the passage of a weak cold front. Given this is close to a week away did not want to spend too much time here as there is pounds of time between now and then for things to change.
Forecaster Confidence Levels:
Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent.
* Arctic front this morning with NW winds up to 30 kt * Winds slowly ease this afternoon & then diminish tonight
Thursday... Arctic front moving thru the coastal waters during the predawn hours, with a wind shift to the NW with gusts up to 30 kt. Brief rain/snow showers will accompany the frontal passage. NW winds ease a bit this afternoon, 15-25 kt.
Thu night... NW winds diminish as high pressure builds into New England from the west. Dry weather and good vsby.
Friday... Quiet/tranquil weather in the morning as high pressure lingers over the eastern waters. Then a warm front approaches the waters from the south. Light winds become SSE and increase 15-20 kt late. Dry weather and good vsby in the morning, gives way to rain late in the day.
Outlook /Friday Night through Monday/... Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Rain. Visibility 1 to 3 nm.
Saturday: Moderate risk for gale force winds with gusts up to 40 kt. Rough seas up to 14 ft. Rain. Visibility 1 to 3 nm.
Saturday Night: Moderate risk for gale force winds with gusts up to 35 kt. Rough seas up to 13 ft. Chance of rain.
Sunday: Low risk for gale force winds with gusts up to 35 kt. Rough seas up to 11 ft.
Sunday Night: Winds less than 25 kt. Local rough seas.
Monday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of seas approaching 5 ft.
NOAA Boston MA Office: Watches - Warnings - Advisories
CT...None. MA...None. RI...None.
Small Craft Advisory until 9pm EDT this evening for ANZ230. Small Craft Advisory until 1am EDT Friday for ANZ231-251. Small Craft Advisory until 7pm EDT this evening for ANZ232>237. Small Craft Advisory until 5am EDT Friday for ANZ250-254. Small Craft Advisory until 4am EDT Friday for ANZ255-256.