AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 315 PM EDT Fri Apr 3 2026 .WHAT HAS CHANGED... Gale watches issued for our southern waters on Sunday. && .KEY MESSAGES... - Another backdoor front brings a return to colder air later Saturday. More showers arrive Saturday night. - A period of widespread showers on Sun with highs mainly in the upper 50s and lower 60s. - Mainly dry and chilly Mon-Wed except for a brief period or two of rain/snow showers sometime later Mon into Tue. Odds of any road/travel impacts are low at this time. - Milder temps return Thu into Fri with highs likely rebounding well into the 50s if not 60s with mainly dry weather. && .DISCUSSION... KEY MESSAGE 1...Another backdoor front brings a return to colder air later Saturday. More showers arrive Saturday night. A low pressure moving across southeast Canada will maintain a gusty southwest wind across southern New England for most of tonight. This will mean warmer conditions, with expected low temperatures just slightly lower than our normal high temperatures for early April. Still plenty of clouds lingering across our region, but we should be able to eliminate the drizzle away from the immediate coastal plains of RI and southeast MA. Thinking southern New England should have a brief window of clearer skies Saturday morning as a cold front briefly moves south of our region. This front returns back north as a warm front late Saturday night, but most likely does not arrive until later Sunday. The main impacts will be increasing clouds Saturday afternoon into the overnight. Thinking the NationalBlend guidance was a little too aggressive in returning rainfall chances as quickly as it did. Tempered that timing with more of a model consensus. Still a chance of showers Saturday night, but mainly after midnight. KEY MESSAGE 2...A period of widespread showers on Sun with highs mainly in the upper 50s and lower 60s. Low pressure will be lifting well to our north across Quebec on Sunday. A trailing cold front extending south from the low will approach from the west. Ahead of this cold front, a modest southwest LLJ/PWAT plume about 2 standard deviations above normal will work into the region. This should help to mix out the lingering shallow cool inversion in most locations by afternoon. Clouds will limit the high temp potential, but highs should still recover into the upper 50s and lower 60s in many locations. The LLJ/Pwat plume will also result in but enough forcing for a period of widespread showers and a few downpours on Sun. The system is fairly progressive, so the main shield of showers will probably only last 2-4/3-5 hours in a given location. Instability is rather marginal, so would not expect more than perhaps a rumble or two of thunder if even that. KEY MESSAGE 3...Mainly dry & chilly Mon-Wed except for a brief period or two of rain/snow showers sometime later Mon into Tue. Odds of any road/travel impacts are low at this time. The ensembles continue to show very good agreement in an upper trough setting up across the northeast. This will result in cool temperatures with mainly dry weather. However, a couple of strong but moisture starved shortwaves may bring a brief period or two of rain/snow showers sometime later Mon into Tue. In fact, the guidance indicates that the 500T mb temps will drop to between -30C and -35C! This will certainly increase the risk for those brief instability rain/snow showers and perhaps a bit of graupel too. That being said, odds of any road/travel impacts are relatively low at this point. Otherwise, dry weather with high temps mainly in the middle 40s to the lower 50s. It will be at night with lows mainly in the 20s to the lower 30s! KEY MESSAGE 4...Milder temps return Thu into Fri with highs likely rebounding well into the 50s if not 60s with mainly dry weather. Large high pressure shifts east of the region by the end of the work week. The result will be a milder southwest flow of air back into southern New England. High temps should recover well into the 50s if not 60s by Thu and Fri. Thinking mainly dry weather at this point given the lack of synoptic scale forcing. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Through 00Z...High confidence in trends. Moderate confidence in timing. Improving to VFR away from the immediate south coast. Local east coast seabreezes for MA with the sudden rise in temperature as sunshine develops. Tonight...High confidence. VFR for most, with IFR likely to linger towards the south coast of New England, especially the Cape and islands. Patchy fog and drizzle there. Gusty SW winds with some LLWS due to a low level jet just above an inversion for most of tonight. Wind shear diminishes early Saturday morning. Winds turn W then NW behind a cold front late tonight. Saturday...High confidence. VFR for most. Some lingering MVFR possible for the Cape and Islands in the morning. Winds swing around to ENE Saturday. ENE winds in afternoon at 10-15 kts with gusts up to 20 kts. Saturday Night...Moderate confidence. MVFR develops Saturday evening, with IFR expected after midnight. KBOS Terminal...High confidence in trends. Sea breeze developed once the sunshine developed. Southwest winds should develop towards the start of the evening push. KBDL Terminal...High confidence. Outlook /Sunday through Wednesday/... Sunday: Mainly VFR, with areas IFR possible. Windy with gusts up to 35 kt. SHRA, patchy BR. Sunday Night: VFR. Windy with local gusts up to 30 kt. Slight chance SHRA. Monday: VFR. Windy with local gusts up to 30 kt. Monday Night: VFR. Tuesday: VFR. Breezy. Chance SHRA, slight chance SHSN. Tuesday Night through Wednesday: VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. High confidence. A low pressure moving north of the waters will maintain a general southwest flow for most of tonight. The cold front of this low pressure should cross the waters late tonight, then return back north as a warm front late Saturday night. Locally dense fog is also expected to develop across the waters, especially closer to the Cape and across the Islands and south coastal areas. This fog should last into early Saturday morning. Small Craft Advisories continue for most waters tonight, then gradually and Saturday. Winds will be turning from easterly early this morning to southwest by mid-day, and then start to increase as low pressure far to the west approaches. All the available guidance suggests winds will start gusting around 25kt across much of the waters by this afternoon. Thus another round of Small Craft Advisories will be necessary. These winds will also produce some rough seas. Winds are expected to diminish Friday night and early Saturday as high pressure ridges into the area. Another low pressure system may produce winds near gale force on Sunday. Outlook /Sunday through Wednesday/... Sunday: Low risk for gale force winds with gusts up to 35 kt. Rough seas up to 11 ft. Rain showers, patchy fog. Sunday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain showers. Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Monday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday: Winds less than 25 kt. Slight chance of rain showers. Tuesday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Wednesday: Winds less than 25 kt. Areas of seas approaching 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 5 AM EDT Saturday for ANZ231>235- 237. Gale Watch from Sunday morning through Sunday afternoon for ANZ231>235-237-254>256. Small Craft Advisory until 7 AM EDT Saturday for ANZ250. Small Craft Advisory until 1 PM EDT Saturday for ANZ254>256. && $$