AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 803 PM EDT Wed Mar 11 2026 .WHAT HAS CHANGED... Small Craft Advisories extended for some waters into Friday. Cold front moving across our region late tonight into Friday could allow for hit-or-miss showers or even a rumble of thunder tonight for some. && .KEY MESSAGES... - Cold front moves across our region late tonight into midday Thursday. Expecting falling temperatures through the day. Even a risk for minor snow accumulation across interior southern New England, depending on the timing of the subfreezing air. - Light snow Friday PM. Minor accumulations possible for higher elevations. Gusty winds Saturday. - Widespread rain with locally heavy rainfall Sunday night into Monday which may lead to minor river flooding. Another period of gusty winds Monday. && .DISCUSSION... KEY MESSAGE 1...Cold front moves across our region late tonight into midday Thursday. Expecting falling temperatures through the day. Even a risk for minor snow accumulation across interior southern New England, depending on the timing of the subfreezing air. Much of our weather into Thursday will depend on the timing of a cold front moving past southern New England. Expecting scattered showers for most, with the possibility of a thunderstorms closer to the cold pool aloft moving across the Great Lakes into northern New England. Once this front moves on by, colder air should arrive. Air cold enough to result in falling temperatures during the daytime. That said, expecting low temperatures to return to near normal for mid March by Thursday night. Thinking showers will be most widespread across our region after midnight into mid morning Thursday. Depending on how quickly temperatures fall, there is the possibility for light snow across the higher terrain towards the Berkshires mainly, but perhaps also into the Worcester Hills. Conditions should be drying as this snowfall develops, so not expecting much more than a coating to an inch. KEY MESSAGE 2...Light snow Friday PM. Minor accumulations possible for higher elevations. Gusty winds Saturday. Mainly dry conditions expected on Friday with seasonable temperatures. Next shortwave trough is expected to move through the region Friday night into Saturday. Model guidance shows a signal for marginal moisture to push into the region ahead of the wave. Scattered showers are possible Friday afternoon and Friday night. These showers are more likely to be snow showers for the high elevations. Rain/snow mix is possible for the lower elevations. Any accumulations are likely to be light. Generally up to an inch for northwest/north-central MA higher elevations, perhaps locally higher amounts for the highest elevations of the northern Berkshires. Elsewhere, a coating to a half an inch is more likely for the remainder of MA, northern CT (excluding the Cape). A cold front swings through overnight into Saturday morning. A moderate jet and enhanced gradient along with CAA will allow mixing down of stronger winds aloft to the surface. There is some uncertainty among guidance on how strong the jet will be. Gusts 35-45 mph are possible with the higher winds across the higher elevations and Cape/Islands. There are moderate probabilities 50-60% for gusts greater than 45 mph for the highest terrain of the Berkshires and Worcester Hills. Something that we will have to keep an eye on for potential Wind Advisory headlines. KEY MESSAGE 3... Widespread rain with locally heavy rainfall Sunday night into Monday which may lead to minor river flooding. Another period of gusty winds Monday. A shortwave trough approaches the region Sunday with a LLJ ahead of it. This will shift winds southwest and help advect in moisture rich air northward into southern New England. Moisture will be fairly above normal with precipitable water amounts 200-280% of normal. Marginal instability associated with this system along-side the anomalous precipitable water values raises the potential for locally heavy rainfall, convective cells, and perhaps an isolated thunderstorm embedded in the rain. Ensemble probabilities for greater than 1" of rain range from 30-60% generally. The ECMWF ensemble members are leaning wetter than the GEFS, even highlighting higher probs closer to 70% for RI, CT, and SE MA for 1" or greater of QPF. Upper percentiles for total QPF run 1 to a little over 2" across ensemble guidance. This does raise concern for rising river/stream levels from snowmelt and additional rain. MMEFS ensemble guidance shows potential (40-60%) for rivers reaching minor flood levels early next week (Pawtuxet, Taunton, Pawcatuck rivers). Low probs to reach minor flood along the lower reaches of the mainstem Connecticut River from Hartford through Middle Haddam. A strong southerly LLJ shifts across the region Monday. This will produce gusty south winds. There is uncertainty in the degree of mixing we will get to the surface from that LLJ, so the magnitude of gusts remains less certain. Regardless, it will likely be generally gusty Monday with milder temperatures. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 00z TAF Update: Tonight Through 00z Friday: Moderate confidence. This is a pretty active, changeable aviation forecast period. Generally VFR initially in increasing S winds for most airports, NE flow has resumed in northeast/eastern MA which has brought IFR- LIFR ceilings, and coastal mist/fog has developed along the south coast. It looks as though this stationary frontal boundary retreats north between 01-03z, bringing a windshift to S winds around 10-15 kt. LIFR may linger along the south coast but some modest categorical improvement to MVFR, perhaps VFR as winds turn southerly. While this occurs, strong SW LLJ of 50-55 kt will continue to lead to low level shears, which won`t improve until overnight. Next concern is between 04-08z as a round of showers, with heavier showers/embedded thunderstorms for TAFs near or south of Interstate 90 moves in. This stems from ongoing stg/svr convection in the mid-Atlantic states, expected to weaken but zone of elevated instability could still sustain a risk for lightning and thunder (reflected in TAFs with PROB30s), although strong storms are not expected. Brief clearing from west to east between 08-12z with categories in the MVFR range for most airports. Southerly winds around 10-15 kt with gusts 20-25 outside of storms. A cold front will then be moving through SNE between 13-19z Thurs west to east, which will bring a gusty windshift to WNW around 15-18 kt with gusts 25-30 kt. Cooling temperatures will allow for initial rain, but rain should mix with PL and then SN with MVFR visby/MVFR-IFR ceilings from 18-00z. Up to an inch of snow accum possible on grassy surfaces although runways should be wet given preceding spell of warm temperatures. Thursday Night: High confidence. Rapid improvement to VFR. NW winds around 10 kt. Even though temperatures will be subfreezing, rapid drying should limit any freeze-up on runways. KBOS Terminal...Moderate confidence. LIFR stratus/mist to persist thru 02z Thurs as NE winds shift to S. MVFR ceilings then linger until a risk for light to moderate showers between 04-09z Thurs. Clearing after 09z Thurs but another risk for rain takes place around 14z with a gusty windshift to NW as cold front moves thru. Cooling temps after 18z could bring a risk for rain mixed with PL then brief SN, although runways should be dry. KBDL Terminal...Moderate confidence. VFR initially but categories turn MVFR after 04z, with period of SHRA, embedded TS possible (indicated as PROB30) 04-08z. VFR/MVFR ceilings after 08z before cold front brings resuming risk for rain and a gusty NW windshift after 13z. Cooling temps could support mixover to PL then SN after 17z Thurs. Outlook /Friday through Monday/... Friday: VFR. Breezy. Slight chance RA. Friday Night: Windy with local gusts up to 30 kt. Chance RA. Saturday: Windy with gusts up to 30 kt. Saturday Night: Breezy. Sunday: Breezy. Slight chance RA. Sunday Night: Strong winds with local gusts up to 40 kt. Chance RA, chance FZRA, slight chance TSRA. Monday: Strong winds with areas of gusts up to 45 kt. RA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Rough seas linger across the outer coastal waters into Friday morning. A cold front moving across the waters late tonight into Thursday will also generate gusty SW winds at times until it passes. Poor visibility at times in fog expected tonight, and also the risk for a few showers. Becoming clearer with gusty W to NW winds Thursday into Thursday night. Outlook /Friday through Monday/... Friday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of seas approaching 5 ft. Friday Night: Strong winds with gusts up to 35 kt. Areas of rough seas. Chance of rain. Saturday: Strong winds with gusts up to 35 kt. Rough seas up to 11 ft. Saturday Night: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Local rough seas. Sunday: Winds less than 25 kt. Sunday Night: Strong winds with gusts up to 40 kt. Areas of rough seas. Rain likely, slight chance of thunderstorms. Monday: gale force winds with gusts up to 45 kt. Rough seas up to 13 ft. Rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 7 PM EDT Thursday for ANZ232-233. Small Craft Advisory until 1 PM EDT Thursday for ANZ234. Small Craft Advisory until 7 AM EDT Friday for ANZ235-237-250- 254>256. && $$