Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 290934 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 534 AM EDT Thu Sep 29 2016 .SYNOPSIS... Onshore winds will bring spotty light rain along with patchy drizzle and fog across southeast New England through midday, with a brief break this afternoon. A low pressure wave will pass south of the region, bringing cloudy, cool conditions with showers Friday through Saturday which may linger into Sunday. Conditions will improve somewhat early next week, but still can not rule out a period of showers. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Noted thin bands of light showers that moved onshore across SE Mass into RI in the NE fetch early this morning. Would not be surprised to see spotty drizzle and patchy fog along east coastal areas through mid to late this morning as well. Steady NE winds continue, with gusts between 25-30 kt reported from KBOS south to KPVC and KACK since 06Z. Low clouds continue to linger across the region at 08Z, but noting somewhat drier air and back edge of clouds working southwestward down from the ME/NH coast into NE Mass as seen on latest IR satellite imagery, so clouds could lift by around 12Z-14Z as it works SW. However, also seeing mid and high clouds heading NE out of the mid Atlantic states around the H5 cutoff low pressure spinning across the Ohio and Tennessee valleys. Continued strong pressure gradient between the 1038 hPa high across southern Quebec and the low to the SW, will continue to see gusty NE winds especially along the coast. Expect gusts up to 30-35 mph today, possibly a bit higher along the immediate shore. Temps will not recover much today, only reaching 60-65 degrees for most areas under mainly cloudy skies. Could see a few breaks in the clouds around the Route 2 area of N Mass this afternoon with somewhat drier air working in there. Will feel really chilly and raw along the coast with the cool temps and strong winds, though. Due to the persistent and strong NE winds, have issued a High Surf Advisory for east facing coastlines of Cape Ann, outer Cape Cod and Nantucket through 6 PM today. High risk of rip currents as well as some possible splashover around the time of high tide late this morning to midday. Also near a new moon phase so somewhat higher astronomical tides. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Tonight and Friday... Any breaks in the clouds early tonight across northern areas will be short lived as mid and high level moisture works N-NW especially after midnight. Persistent NE winds will keep raw conditions in place, though gusts will tend to drop off late. Overnight lows will be close to this morning`s lows, ranging from the upper 40s across the higher inland terrain to the mid and upper 50s along the immediate coast. On Friday, a wave of low pressure will try to push NE, but will stay offshore. However, a plume of moisture will work northward in the mid level wind flow. PWATs will increase to 1.9 to 2 inches across S coastal areas by late in the day. Slug of precip also looks to shift N, with the best shot for precip across N CT/RI and SE Mass. QPF amounts could reach 0.3 to 0.5 inches during Friday, highest along the immediate S coast. The fight between drier low level air and the higher moisture aloft will make it tough to get appreciable rainfall north of the Mass Pike, where a tenth of an inch or less is forecast at this point. Have carried likely POPs near and south of the Mass Pike for most of Friday. Expect highs in the mid to upper 50s across the inland terrain ranging to the lower-mid 60s elsewhere. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Highlights... * Periods of showers and drizzle into Sat with cool afternoons * Some showers and drizzle may linger into Sunday * Drier weather Mon-Wed but a period of showers remain possible Details... Friday Night and Saturday... Strong high pressure across eastern Canada will combine with a low pressure emerging off the mid Atlantic coast to produce a period of wet weather across most of southern New England. Although this surface low is not too strong, expecting gusty northeast winds along the coast, especially across the Cape and islands. While measurable rainfall will occur, its uncertain if 1+ inch amounts will make it into any of our region, or remain to our south where better low level forcing resides. The most likely areas to get heavier rainfall should be the Cape and islands, which will be closer to the low circulation. Onshore flow, clouds and periods of showers will keep high temperatures below normal for late September. Sunday... The Mid Atlantic low pressure moves farther east, allowing the pressure gradient to weaken. However, high pressure over the Maritimes will still still generate a moist, northeast flow. Depending on the exact timing, some showers and drizzle will probably linger into Sunday, especially along the eastern MA coast. High temperatures will likely remain below normal given lingering low clouds. Monday through Wednesday... Another high pressure will build down into eastern Canada and northern New England early next week. While a shortwave may bring a period of showers, a good shot at dry weather for a decent portion of this time frame. Northeast winds at the surface much of the time will probably continue to hold high temperatures near to below seasonable levels. We also will have to keep a close eye on what is expected to become Hurricane Matthew over the Caribbean. Most model guidance suggests this system will remain south of our region through Wednesday of next week. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday/... Today...Moderate confidence. Expect mainly MVFR to low end VFR CIGS with mainly VFR VSBYS for most of today. May see MVFR VSBYS along the immediate coast near and S of Boston with onshore flow that may produce -SHRA/-DZ at times through midday. Patchy IFR CIGS through mid morning across outer Cape Cod and Nantucket possible. NE winds gusting to 25-30 kt across E Mass, possibly reaching into RI. Tonight...Moderate confidence. Mainly VFR tonight near and N of the Mass Pike. Low end VFR-MVFR CIGS move into southern areas, and may see IFR CIGS/VSBYS move into S coastal areas after midnight as sct -SHRA start to move in. Gusty NE winds to 25-30 kt continue along the east coast. Friday...Low confidence, mainly for timing. Will see MVFR-IFR CIGS and/or VSBYS as -SHRA and patchy fog moves in from S-N during the day. NE wind gusts up to 25 kt continue along the coast. KBOS TAF...Moderate to high confidence in TAF. KBDL TAF...Moderate to high confidence in TAF. Outlook /Friday Night through Monday/... Friday Night through Sunday...High confidence. Mainly MVFR to IFR conditions in low clouds, periods of showers/drizzle and patchy fog. Northeast wind gusts of 20 to 30 knots expected along the coast, and perhaps a bit stronger across Nantucket. Monday...Low confidence. May see improvement to mainly MVFR conditions. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday/...High confidence. Gale warnings issued for portions of the south coastal waters as winds gust up to 35 kt late tonight through midday Friday. Small crafts remain in effect for remaining waters. Expect NE winds to continue, with general gusts up to 25-30 kt most waters. Seas up to 8-10 feet, highest over the eastern open waters. Winds will gradually diminish during Friday, but will still see gusts to around 25 kt along with seas up to 7-9 ft. Outlook /Friday Night through Monday/... Friday Night into Saturday Night...High confidence. Rough seas expected to continue across the outer coastal waters. Seas gradually subside as winds diminish Saturday night. Small craft advisories needed at a minimum during this time. Still a possibility of gale warnings continuing for some of the southern coastal waters Friday Night. Sunday and Monday...Moderate confidence. Pressure gradient weakens, so expecting winds and seas to remain below small craft advisory thresholds. Some risk for rough seas to linger across the outermost eastern coastal waters. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...High Surf Advisory from 8 AM this morning to 6 PM EDT this evening for MAZ007-022-024. RI...None. MARINE...Small Craft Advisory until 6 PM EDT Friday for ANZ231>236-250- 251-254. Small Craft Advisory until 6 PM EDT this evening for ANZ230. Gale Warning from 2 AM to 8 PM EDT Friday for ANZ237-256. Gale Warning from 8 AM to 8 PM EDT Friday for ANZ255. && $$ SYNOPSIS...Belk/EVT NEAR TERM...EVT SHORT TERM...EVT LONG TERM...Belk AVIATION...Belk/EVT MARINE...Belk/EVT is the U.S. government's official web portal to all federal, state and local government web resources and services.