NWS Forecaster Discussion
BOX
Area Forecast Discussion National Weather Service Boston/Norton MA.
527 FXUS61 KBOX 070607 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 107 AM EST Sun Dec 7 2025 .SYNOPSIS... Showers exit this afternoon as do the clouds. An arctic front moves through overnight Sunday into Monday morning with a some brief scattered snow showers possible. Well below normal temperatures Monday before slowly moderating Tuesday/Wednesday. More unsettled overall next week with a few disturbances moving through bringing periodic chances for rain/snow showers Tuesday night into Saturday. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Key Messages... * Showers and clouds clearing through the afternoon/evening. * Warmer tonight with lows in the 20s. Skies will continue to clear through the afternoon and evening as the last of the showers shifts offshore. Moisture exits with a drier airmass shifting overhead coinciding with the arrival of surface high pressure and a weak front. While the mid/upper levels dry out, lingering low level moisture around 950mb likely leads to some low level stratus over the interior for part of the overnight hours. Lows drop into the upper teens (high elevations) and 20s. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... Key Messages... * Mix of clouds and sun Sunday. * A weak disturbance brings intermittent light showers to northern MA overnight. Sunday features surface high pressure to start under zonal mid level flow so expecting dry, quiet weather to end the weekend. The first half of the day will feature the most sun, with clouds steadily filling in in the afternoon ahead of a weak mid level shortwave that crosses northern New England overnight. This is accompanied by a stronger but moisture starved cold front at the surface. Thus, not much has changed from the previous forecast, expecting a smattering of light snow showers to be possible mainly north of the MA pike amounting to a coating (more likely) to a half inch or so (less likely). Thanks to that front, lows will be colder than Saturday night, in the teens and low 20s. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Key Messages: * More arctic air arrives early next week. * Few snow showers possible early Monday. Very light accumulations, if any (< 1.0"). * Periodic chances for precipitation Tuesday night into next weekend. Low confidence in the details for timing and amounts. Low pressure departs Monday, only to be followed by an arctic airmass for Monday night into Tuesday. Another low pressure should move from the Great Lakes into eastern Canada Wednesday into Thursday. Then southern New England should be stuck between a couple of features Friday into Saturday, a low pressure well offshore to our east and a large high pressure over the northern Plains. Looking for well below normal temperatures Monday and Monday night as arctic air passes overhead. Temperatures then expected to trend warmer Tuesday, before being near normal for Wednesday. Temperatures then trend below normal late next week, with another round of arctic air possible. Mainly dry Monday as a low pressure departs, which should then continue into Tuesday afternoon. After then, the timing and track details get complicated. The consensus track is for a low pressure to remain to our west and north during the middle of next week, but it could get close enough to our region to bring some light precipitation to our region. First with the warm front and then with the cold front of this system. It`s still early enough in the season where there would be a rain/snow line somewhere, with water temperatures still in the 40s. Time of day will also matter greatly in determining precipitation type. Generally favoring snow at night and across the higher terrain, with rain more likely towards the coastal plains of MA and RI. Late next week could feature some cold advection showers, but there are no strong lifting mechanisms anticipated at this time. There are also questions about the amount of moisture which could be available. While there is a prolonged period where these showers are possible, there should be many dry hours late next week. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06Z TAF Update: Through 12Z Today...High confidence. VFR. NW winds around 5 kt. Areas of stratus early this morning. Confidence moderate for timing that the stratus scatters out, but more likely by 12Z. Today...High Confidence. VFR. NW winds 5-10 kts. After 18z, winds briefly may go VRB before shifting to the S and SE/ESE for BOS. Winds continue to shift toward the W/WSW after 00Z. Mid-level ceilings move in during the afternoon. Tonight...High Confidence. VFR. Mid-level ceilings early tonight. Winds shifting toward WSW after 00z 5-10 kts. Frontal passage overnight between 05-09Z. Slight chance of -SN for northern terminals. Probabilities too low to include in TAF. Monday...High Confidence. VFR. Gusty NW winds with gusts 20-30 kts. Winds gradually decreasing after 18Z. KBOS Terminal...High Confidence in TAF. KBDL Terminal...High Confidence in TAF. Outlook /Monday Night through Thursday/... Monday Night through Tuesday: VFR. Breezy. Tuesday Night: VFR. Breezy. Slight chance SN. Wednesday: Mainly VFR, with local MVFR possible. Breezy. Chance RA, chance SN. Wednesday Night: Mainly VFR, with local IFR possible. Breezy. Chance RA, chance SN. Thursday: Mainly VFR, with local MVFR possible. Breezy. Chance RA, slight chance SN. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tranquil boating conditions expected through Sun, with winds and seas below small craft advisory thresholds. Light S winds continue into most of today, then become NW tonight around 10-15 kt. Seas 3 ft or less all waters thru Sun. Outlook /Monday Night through Thursday/... Monday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday Night: Moderate risk for Small Craft Advisory winds with local gusts up to 30 kt. Local rough seas. Slight chance of rain. Wednesday: Moderate risk for Small Craft Advisory winds with areas of gusts up to 30 kt. Local rough seas. Chance of rain. Wednesday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Chance of rain. Thursday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain. && .TIDES/COASTAL FLOODING... Coastal Flood Statement issued for this morning`s high tide cycle along the eastern MA coast and Nantucket due to astronomical king tides. This is expected to be marginal as winds and swell aren`t as favorable. Some splashover and some minor coastal flooding are possible in low lying areas/roads. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Belk/BW NEAR TERM...BW SHORT TERM...BW LONG TERM...Belk AVIATION...Hrencecin/Mensch MARINE...Belk/BW TIDES/COASTAL FLOODING...Hrencecin