AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 606 AM EST Mon Dec 8 2025 .SYNOPSIS... Well below normal temperatures today and tonight with an arctic airmass overhead. Slight improvement temperature-wise Tuesday before peaking Wednesday. More unsettled overall next week with a few systems moving through the region. This will bring periodic chances for rain/snow showers starting Tuesday night, continuing into Saturday. Trending cooler later in the week with below normal temperatures returning by the end of the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Key Message: * Breezy, cold, and dry following arctic cold frontal passage High pressure begins to move in following this morning`s arctic cold front, and the surface low pressure associated with it moves offshore to the NE. With the low still expected to be over the Gulf of Maine for this morning, the gradient between it and the approaching high pressure from the Great Lakes will be conducive to breezy conditions through the first half of the day. Gusts to 25-30 mph will be possible through around noontime before dropping off as the low shifts further to the NE. Some mid-level clouds may creep in throughout the day with the colder airmass overhead. Very dry conditions expected with wind chills in the teens despite high temperatures in the 20s. Highs may reach the low 30s for the Cape and Islands. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Key Messages: * Dry and unseasonably cold tonight with diminishing winds * Sunny to start with clouds filling in for the second half of Tuesday Winds continue to drop off tonight as the pressure gradient slackens and high pressure settles overhead. 925 mb temperatures sink to around -15C. Skies clear as well, allowing for strong radiational cooling overnight. Forecast soundings indicate very dry conditions, so the chance for some patchy fog is low. Lows drop into the single digits for the interior and the low to mid teens along the coasts; Cape Cod and Nantucket could reach the low 20s. Unseasonably cold conditions continue through early Tuesday morning before high pressure overhead starts to shift east in the afternoon, leading to the start of some warmer air advecting in with SW winds. 925 mb temperatures will improve slightly to just above -10C in the afternoon/evening hours as a result, and highs will improve to the upper 20s inland and mid to upper 30s along the coasts. Clearer skies in the morning will also start to fill in during the second half of the day ahead of an approaching disturbance and its fronts. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Key Messages: * Periodic chances for precipitation next week starting Tuesday night, continuing through Saturday. * Uncertainty in pattern details (timing, amounts, precip type), especially Wednesday onward. Details... Ensemble guidance displays a consensus for generally active/unsettled weather pattern Tuesday through at least Saturday with several disturbances moving through the flow aloft. This will bring periodic chances for precipitation. Although, as we head toward later in the week, details such as timing and amplitude become less agreed on amongst model guidance resulting in lower confidence. Surface high pressure shifts offshore on Tuesday ahead of the first shortwave trough. Flow turns to the southwest with temperatures moderating back into the 30s and near 40 for the Cape/Islands. First shot at showers comes Tuesday night into Wednesday. Any showers are likely to be scattered and light with snow showers, especially for the interior MA. Depending on track/temps, rain showers are possible for parts of SE MA and the Cape/Islands. Ensembles display trace to half an inch, if any accumulates (mainly higher terrain of interior MA). Low pressure tracks through the Great Lakes Wednesday bringing in higher amounts of moisture and a round of more widespread precipitation. A warm front will bring in warmer temperatures during the day supporting highs in the 40s for most areas. The higher terrain of the interior will be a bit trickier with temperatures in the mid to upper 30s. This may bring a rain/snow mix or snow to locally higher terrain. Because of this, there is some uncertainty in accumulations in those areas, if any. Ensembles show potential for light accumulations ranging from a trace to 3.0" in the localized higher terrain spots of west and central MA. A drier airmass moves in on Thursday with cooler air advecting back into the region as a deeper mid-level trough sits across the northeast. There may be just enough residual moisture to support a few cold advection snow showers or a streamer to make it over the Berkshires. Likely no impacts. Ensembles point to the potential for another system to move through Saturday bringing yet another round of precipitation. This is pretty far ahead, so it`s no surprise that models are wavering in track/amounts amongst each other and from run to run. Details will become more clear as we get closer. There is general agreement with a colder airmass to move back in by the end of the weekend bringing back below normal temperatures Sunday. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 12Z TAF Update: No significant changes from the previous forecast. Monday...High Confidence. VFR. Gusty NW winds with gusts 20-30 kts. Winds gradually decreasing after 18Z. Monday night...High Confidence. VFR. Winds light and variable. Tuesday...High Confidence. VFR. Light SW to S winds. Increasing mid-level clouds in afternoon. KBOS Terminal...High Confidence in TAF. KBDL Terminal...High Confidence in TAF. Outlook /Tuesday Night through Friday/... Tuesday Night: Mainly VFR, with local MVFR possible. Breezy. Chance SN, chance RA, slight chance FZRA. Wednesday: Mainly VFR, with local IFR possible. Windy with local gusts up to 30 kt. Chance RA, chance FZRA, chance SN. Wednesday Night: Mainly VFR, with local IFR possible. Windy with local gusts up to 30 kt. Chance RA. Thursday through Thursday Night: VFR. Breezy. Friday: VFR. Breezy. Slight chance SN. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today...High confidence. A cold front passes over the waters early this morning. The gradient between the exiting low and approaching high pressure will be conducive to windy conditions. Seas build to 5-7 ft over the outer waters through today. Gusts between 20-30 kt possible across all waters this morning, with occasional gusts to 35 kt possible for the northern outer waters. Small Craft Advisories are in effect for the waters through 06z Tue for the outer waters and ending at 21z today for the coastal waters. Tonight...High confidence. N winds 10-15 kts gusting 15-20 kts early, diminishing through the night. Seas decreasing to 2-4 ft after midnight. Tuesday...High confidence. Light N winds Tue AM become SW/SSW at 10-15 kts after 18z, gusting to 20 kts in the evening hours. Seas 2-3 ft. Outlook /Tuesday Night through Friday/... Tuesday Night: Moderate risk for Small Craft Advisory winds with local gusts up to 30 kt. Local rough seas. Chance of rain. Wednesday: Low risk for gale force winds with gusts up to 35 kt. Areas of rough seas. Chance of rain. Wednesday Night: Strong winds with gusts up to 35 kt. Areas of rough seas. Chance of rain. Thursday: Moderate risk for Small Craft Advisory winds with local gusts up to 30 kt. Areas of rough seas. Slight chance of rain. Thursday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Slight chance of rain. Friday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of seas approaching 5 ft. Slight chance of rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 4 PM EST this afternoon for ANZ231>235-237-251. Small Craft Advisory until 1 AM EST Tuesday for ANZ250-254>256. && $$