AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 645 AM EST Fri Jan 9 2026 .WHAT HAS CHANGED... Forecast remains in good shape with few wholesale changes at this time. That said, be aware of black ice this morning and areas of freezing fog. Light rain showers expected tonight, more widespread rainfall Saturday evening into Sunday. Growing potential for localized freezing rain for northern portions of the higher terrain Saturday night into early Sunday. Confidence is growing for gusty west winds Sunday night into Monday. && .KEY MESSAGES... - Black ice and freezing fog possible this morning, followed by a mild and dry afternoon. Showery light rain tonight into tomorrow morning. - Another round of rain Saturday night into Sunday. Localized freezing rain possible for higher elevations of interior MA. - Cold front brings gusty west winds and cooler temperatures Sunday night into Monday. && .DISCUSSION... KEY MESSAGE 1...Black ice and freezing fog possible this morning, followed by a mild and dry afternoon. Showery light rain tonight into tomorrow morning. 1025mb high pressure is centered east of the Delmarva Peninsula and shifts northeast towards Nantucket early this morning, then shifting into the North Atlantic late tonight. Clear skies early this morning has allowed temperatures to fall below freezing, lingering moisture on untreated surfaces to refreeze and create slick conditions. The high shifts east of the Delmarva early this morning, leading to a return flow of light southerly wind. This ushers a relatively warmer airmass into southern New England. While it`s not a slam dunk, there is potential for enough moisture to advect north to allow for areas of freezing fog to develop. Don`t expect a widespread dense fog, thinking visibility restrictions are between 1-3 miles. Where there could be localized dense fog are those typical prone locations where cold air pools. Nevertheless, please drive safely this morning. Will have improvements between 8 AM and 10 AM as temperatures increase above the freezing mark. Mild afternoon with 925mb temperatures +4C to +6C, despite the cloud cover, afternoon highs reach the mid to upper-40s. Cannot rule out a few areas in southeastern Massachusetts touching 50F. Southerly flow increases during the afternoon, gusting 20 to 25 MPH. Warm front lifts over southern New England this evening and tonight with showery rain possible. A widespread washout isn`t expected. As mentioned previously, the best forcing is displaced well north, across northern New England and southern Quebec. Still, a few light rain showers arrive across western Massachusetts and Connecticut between 5 PM and 7 PM, then central and eastern Massachusetts and Rhode Island between 7 PM and 9 PM. Despite higher than normal PWATs, do not expect much QPF, once again due to lack of forcing. Rain totals range between 0.1" and 0.2". Showers exit off the coast between 12 AM and 3 AM Saturday as the trailing cold front pushes through the region. Not as cold, lows are in the middle to upper- 30s. Though, the Berkshires likely drop to the low-30s, here there would be a threat of black ice overnight. KEY MESSAGE 2...Another round of rain Saturday night into Sunday. Localized freezing rain possible for higher elevations of interior MA. Cold front collapses south of the region early Sunday, becoming quasi-stationary to the south of southern New England. This leads to drying conditions on Saturday, through at least the early afternoon before the next system moves in later on. A more dynamic system will moves into the region Saturday evening with a secondary surface low tracking across the Cape/Island or just offshore. An enhanced SW jet will help transport above normal moisture into southern New England, around 230-280 percent of normal. This will set the stage for a soaking rain for southern New England. Rain will likely arrive in the afternoon spreading from south to north, tapering off early Sunday morning. Showers may linger across the south coast and Cape/Islands through the afternoon. There is still a decent range in QPF likely owing to track of the surface low. There continues to be a fairly wide range in the 25th-75th percentiles among ensemble guidance. For northern MA amounts range from 0.20- 0.50" and 0.40-1.0" for the south coast and Cape/Islands. We continue to monitor the potential for localized freezing rain across the northern high terrain. Light northerly flow with a colder airmass in place to the north may provide some drainage/weak cold air damming into terrain of northern MA later Saturday afternoon into Saturday night. Across model guidance, there is at least a weak signal that this colder air may be stubborn to scour out. Although some model solutions are more aggressive with the cold air than others. For now, opted to blend in a portion of cooler guidance to account for the potential for the colder, around freezing temperatures. Surface temps around freezing and warm nose moving in aloft will bring a marginal set-up for freezing rain profiles. This is still lower probability due to the uncertainty in temperatures and how marginal they are to the freezing mark. Respectively the "higher" probabilities for freezing rain will be for the northern portions of the Berkshires followed by the northern portions of the Worcester Hills. Glaze to 0.10" can`t be ruled out if the conditions end up favorable in those localized areas of the higher terrain. Since confidence is still on the lower end, held off on a Winter Weather Advisory for now. KEY MESSAGE 3...Breezy to gusty westerly winds Sunday night into Monday. A cold front moves through late Sunday into Monday. Cold advection will help mix down at least a portion of the winds from a 850mb LLJ positioned across southern New England. This will result in a period of gusty west winds for southern New England Sunday night into Monday morning. Ensemble guidance shows potential for gusts 25-40 mph with the highest gusts across the higher terrain and Cape/Islands. There are probabilities 60-80% for gusts greater than 40 mph across the Berkshires. Probabilities drop off quickly after that, so a gust to 45 mph isn`t out of the question. Into Monday afternoon gusts drop closer to 25-35 mph as the pres gradient relaxes. With the passage of the cold front Sunday night, a few snow showers or a weak snow squall are possible. Residual mid-level moisture, steepening lapse rates and incoming wind have led to some values in the snow squall parameter. Fields aren`t particularly strong, but are sufficient for a weaker squall or two. Temperatures overnight drop into the 20s for most places. If there is any residual water from the rain over the weekend, this will freeze and bring slick conditions in spots for the Mon AM commute. Looking ahead to next week, cool and mainly dry early in the week with the pattern shifting more active mid-week onward with a few shots at precipitation. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High -greater than 60 percent. TAF Update: 12z Today and Tonight... Moderate Confidence. Pockets of FG/BR this morning in CT Valley, south coast, and Cape/Islands should dissipate from 12-15Z. VFR, becoming MVFR after 20z as a warm front approaches. South to south- southwest winds increasing, gusts 20 to 25 knots after 18z. Areas of SHRA move in from west to east 22z-00z, conditions briefly lower to IFR, showers diminish between 03-06z, improving back to VFR 06-09z, while MVFR lingers on the Cape and Islands through 09z-12z. Wind shifts to the west to west- northwest between 04z-10z, winds speeds are 5 to 10 knots, slightly higher for coastal terminals. Saturday... Moderate Confidence. VFR to start, then lowering to MVFR from south to north, along with showery rain, mainly after 18z/21z. Light north wind becomes east at 5 to 10 knots. KBOS Terminal... Moderate Confidence. Low probability for light BR around the terminal 12-14Z. KBDL Terminal... Moderate Confidence. MVFR to IFR visibility developing tonight, potential for dense fog and IFR ceilings 09z to 14z. Outlook /Saturday Night through Tuesday/... Saturday Night: MVFR/IFR conditions possible. RA, FZRA. Sunday: Mainly VFR, with areas IFR possible. Breezy. Chance RA, FZRA likely, chance SN. Sunday Night: VFR. Windy with gusts up to 35 kt. Slight chance RA, slight chance SN. Monday: VFR. Windy with areas of gusts up to 30 kt. Monday Night through Tuesday: VFR. Breezy. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today through Saturday... High Confidence. Winds increases from the south on today as a warm front lifts over the region. Strongest gusts are over the outer ocean waters, 20 to 25 knots this afternoon, then 25 to 30 knots overnight. Seas are increasing this afternoon and tonight 4 to 6 feet, localized areas of 7 feet on the outermost southern waters. Showery rain overnight, not expected to be at all impactful. Saturday morning winds go light and flip to the east as a quasi-stationary front lifts from the south to the north, rain accompanies this front as well during the early to midafternoon. Outlook /Saturday Night through Tuesday/... Saturday Night: Winds less than 25 kt. Local rough seas. Rain. Sunday: Low risk for Small Craft Advisory winds with local gusts up to 30 kt. Areas of rough seas. Rain likely. Sunday Night: Strong winds with gusts up to 40 kt. Rough seas up to 12 ft. Chance of rain. Monday: Strong winds with gusts up to 35 kt. Rough seas up to 12 ft. Monday Night through Tuesday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 7 PM this evening to 3 AM EST Saturday for ANZ235-237. Small Craft Advisory from 7 PM this evening to 7 AM EST Saturday for ANZ250-254>256. && $$