213 FXUS61 KBOX 120626 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 226 AM EDT Sat Apr 12 2025 .SYNOPSIS... Low pressure will lift northeast of the mid-Atlantic coast tonight into Saturday. This will bring mainly rain to areas along and southeast of the Boston to Providence corridor...but some snow and sleet is expected across the interior and especially the higher terrain. Precipitation will taper off to pockets of light rain and drizzle Saturday afternoon. Additional showers are likely in eastern New England on Sunday followed dry and milder conditions Monday. A frontal system will bring another period of showers Monday night into Tuesday then mainly dry and blustery Wednesday and Thursday. The pattern turns unsettled again next Friday. && .NEAR TERM /THROUGH TODAY/... Key Messages... * Rain & wet snow mainly after midnight into Sat AM * Ptype mainly rain southeast of I-95 but some snow/sleet NW of I-95 * 1-4" of wet snow/sleet across interior high terrain * Main impacts to roads confined to elevations at or above 1K feet Details... High pressure over Quebec will be just enough to support another round of wet snow/sleet across interior southern New England later tonight into Sat morning. Low pressure will lift northeast from the mid Atlantic coast tonight. This coupled with high pressure over Quebec will result in a modest easterly LLJ developing across southern New England. While much of the evening will be dry...except perhaps for a bit of rain by late evening near the south coast. The better forcing will arrive from south to north after midnight and continue into Sat morning. Thermal profiles are a touch milder than last night...so Ptype will mainly be rain southeast of I-95 although a few wet snow flakes/sleet pellets may be mixed in at the onset. However...northwest of I-95 enough cooling via dynamic/adiabatic processes to support a period of wet snow and perhaps some sleet. In fact...there is a brief but strong band of mid level frontogenesis with 30-40 units of omega in the snowgrowth region. Therefore...we are thinking a brief burst of 1-4" of wet snow across portions of interior MA. Given marginal boundary layer temperatures and the time of year...roadways will remain wet or only very briefly become slush covered in the lower elevations overnight into Sat morning. However...at elevations near and above 1000 feet roads may become snow covered for a time into Sat morning. Therefore...we did issue a Winter Weather Advisory for the high terrain of the Berks/northern Worcester Hills as well as all of Franklin county. Overnight low temps will mainly be in the lower to middle 30s. It will also become quite breezy along the coast by Sat morning with NE wind gusts of 25 to 35 mph. && .SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/... Key Messages... * Precipitation changes/tapers off to pockets of light rain/drizzle Sat afternoon which continues Sat night with focus near the coast * Quite raw and chilly Sat afternoon & night with temps mainly in the 30s and a gusty NE breeze along the coast Details... Saturday afternoon and night... Low pressure will meander to our south Sat afternoon and night...but the stronger forcing/deeper moisture will lift north of the region. Therefore...expect precipitation to diminish in intensity and areal coverage. Nonetheless...moist onshore flow will continue to result in pockets of light rain/drizzle and fog Sat afternoon and night. It will be raw and quite chilly too with temps generally in the 30s with gusty NE winds near the coast. Temps may hover around freezing in the highest terrain...so some pockets of light freezing drizzle will be possible but with temps near 31/32 do not expect much of an impact. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Key Messages: * Rain lingers across eastern Massachusetts Sunday * More showers Mon night into Tue as a frontal system moves through * Mainly dry and blustery Wed and Thu with below normal temps * Another frontal system may bring an increasing risk of wet weather Fri but timing uncertain. Details... Cutoff low south of New Eng moves to the east during Sun, but deep moisture plume lingering across eastern New Eng will result in a raw day here with on and off showers, gusty N winds and cool temps, while some drying and somewhat milder temps expected in the CT valley. This system moves out by Monday as brief ridging builds in to the region leading to sunshine and seasonable temps. Next northern stream shortwaves will amplify as it moves into New Eng on Tue. The attending cold front will swing through Mon night and will be accompanied by a period of showers. The front moves offshore Tue, but the upper trough is hanging back to the west with shortwave energy rotating through with a secondary cold front so scattered showers expected to develop. Mild temps in the 60s expected. Cooler airmass and blustery conditions settle in Wed-Thu but mainly dry weather with slightly below normal temps. Then next in a series of northern stream shortwaves approaches for the end of the week. Timing and amplitude of this system is uncertain and GFS is more aggressive than ECMWF bringing in showers for Fri. But EPS is wetter than the deterministic run indicating 20-40% probs of greater than 0.10" QPF, while GEFS is showing 40-60%. Will have chance of showers for Fri. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06z TAF Update: Through 12z Saturday: High confidence. Mix of flight categories currently, predominantly VFR/MVFR with plain rain or rain mixed with snow, with areas IFR restricted to the higher terrain in wet snow. Deterioration expected to widespread MVFR-IFR as shield of steady precipitation moves northward from the mid-Atlantic/southern NY area thru 12z Sat. NE winds around 10-13 kt with occasional gusts to 20 kt for the interior, with stronger NE winds around 15 kt with gusts 25-30 kt (up to 35 kt at ACK). Today: High confidence in trends but moderate on exact timing. MVFR-IFR in steady rain (at times mixed with wet snow in lower elevations to I-95), with periods of wet snow and visbys 1-4SM and minor slushy accumulation at ORH/BAF. Steadiest precip shield (liquid and wintry) moves northward from approx 13z south coast to 17z near the northern border with VT/NH, give or take an hour or two. Once that occurs, precipitation tapers off to an intermittent light rain/drizzle with areas of 4-6 SM mist into the afternoon. NE winds 15-20 kt with gusts 20-30 kt, highest near the coasts. Tonight: High confidence, though becomes moderate overnight. MVFR-IFR continues with stratus, fog/mist and drizzle or intermittent light rains. Another shield of steadier light rain moves westward from the ocean towards the eastern MA coast and could make it as far west as central MA/RI between 09-12z Sunday. NE winds around 15 kt with gusts 25-30 kt early shift to N around 8-12 kt with occasional gusts to 20 kt for the eastern MA coast. Sunday: Moderate confidence. MVFR-IFR with areas of drizzle and mist generally continues into Sunday, although there could be some VFR breaks late in the day at BAF/BDL. Best chance at steady light rain is eastern MA and into RI, although its western extent is still a little uncertain. Any rain near the eastern coasts should pull away late. N winds around 8-12 kt become NW and then decrease to 5-10 kt by afternoon. KBOS TAF...High confidence. MVFR to IFR with mostly rain with wet snow mixing in at times 06-08z with NE winds around 15 kt/gusts 20-25 kt. Steadiest rain tapers off around 15-16z to drizzle and mist, although IFR ceilings expected to continue through tonight. KBDL TAF...High confidence. MVFR to IFR with rain and wet snow through mid morning, then steady precip tapers off to drizzle and mist, although IFR ceilings continue into tonight. NE to N winds around 10 kt. Outlook /Sunday Night through Wednesday/... Sunday: MVFR/IFR conditions possible. Breezy. Chance SHRA. Sunday Night: Mainly VFR, with local MVFR possible. Breezy. Monday: VFR. Monday Night: Mainly VFR, with local MVFR possible. Chance SHRA. Tuesday: Mainly VFR, with local MVFR possible. Breezy. Chance SHRA. Tuesday Night: VFR. Breezy. Wednesday: Mainly VFR, with local MVFR possible. Windy with local gusts up to 30 kt. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight through Saturday night...High Confidence. High pressure over Quebec coupled with slow moving low pressure to our south will result in modest pressure gradient. The result will be NE wind gusts of 25 to 35 knots developing later tonight into Saturday with a few gusts up to 40 knots possible across the southern waters. Gale warnings are posted for the southern waters with strong small craft headlines across the northern waters. Winds will only slowly diminish Sat night so will need to continue small craft headlines. Outlook /Sunday Night through Wednesday/... Sunday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 9 ft. Chance of rain showers. Sunday Night: Winds less than 25 kt. Areas of rough seas. Slight chance of rain showers. Monday: Winds less than 25 kt. Areas of seas approaching 5 ft. Monday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers. Tuesday: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers. Tuesday Night: Winds less than 25 kt. Local rough seas. Wednesday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...Winter Weather Advisory until 2 PM EDT this afternoon for MAZ002>004-008-009-026. RI...None. MARINE...Small Craft Advisory until 2 AM EDT Sunday for ANZ230. Gale Warning until 4 PM EDT this afternoon for ANZ231>235-237- 254>256. Small Craft Advisory until 4 PM EDT this afternoon for ANZ236. Small Craft Advisory until 8 AM EDT Monday for ANZ250. Small Craft Advisory until 2 AM EDT Monday for ANZ251. && $$ SYNOPSIS...KJC/Frank NEAR TERM...KJC/Frank SHORT TERM...Frank LONG TERM...KJC AVIATION...Loconto/Hrencecin MARINE...Loconto/Hrencecin