AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 603 AM EST Sat Mar 7 2026 .WHAT HAS CHANGED... No significant changes. Becoming more confident in springtime warmth, especially Tuesday, along with the potential for minor river flooding next week. && .KEY MESSAGES... - Black ice possible early this morning, otherwise a significant warming trend this weekend with the potential to reach 60+ in spots by Sun. Dry weather outside a brief round of showers & perhaps a rumble of thunder late tonight into very early Sun am. - Springtime warmth next week may lead to minor river flooding from melting snow, but we also need to watch a backdoor front to the north, which could bring cooler temperatures Wed-Thu. && .DISCUSSION... KEY MESSAGE 1...Black ice possible early this morning, otherwise a significant warming trend this weekend with the potential to reach 60+ in spots by Sun. Dry weather outside a brief round of showers & perhaps a rumble of thunder late tonight into very early Sun am. Areas of drizzle and spotty freezing drizzle mainly in the high terrain will dissipate by early mid-morning. Until that time...black ice will be a concern especially in the high terrain but can not be ruled out in some lower elevations given temps near freezing. Therefore...will continue the special weather statement until mid- morning. Strengthening 850 MB LLJ will allow the surface winds to shift to a SSW direction by early-mid morning. However...model soundings show an abundance of low level moisture/saturation from the surface to 925 mb. This will result in low clouds hanging tough today. Nonetheless...surface winds becoming SSW will allow afternoon highs to reach the upper 40s to near 50 this afternoon. We will need to watch for advection fog some of which may become locally dense today into tonight near the south coast, Cape & Islands. This a result of southerly advection of high dewpoint air over the very cold ocean. Temps will only drop into the 40s tonight and may actually rise toward daybreak. Dewpoints will also be rising into the 40s...so considerable snow melt will occur over the next 24 hours. A weakening complex of showers and t-storms will approach the region from the west very late tonight into early Sat morning. A round of brief scattered showers and perhaps even a rumble of thunder will be possible. Otherwise...low clouds and fog should eventually scour out on Sunday except perhaps for areas near the south coast. 925T in the +7C to +9C range indicate good potential for highs to approach or break 60 degrees on Sunday...at least away from the south coast. The remaining snowpack will quickly be melting away. KEY MESSAGE 2...Springtime warmth next week may lead to minor river flooding from melting snow, but we also need to watch a backdoor front to the north, which could bring cooler temperatures Wed-Thu. A very warm stretch coming up compared to what we`ve experienced recently. For context, normal high temperatures for early March are in the low to mid 40s. This stretch of warmth, peaking on Tuesday, looks to reach 20 to 25 degrees above normal values, well into the 60s or even 70 in spots. EPS ensemble guidance continues to show 30- 50% chance of reaching 70F though the GEFS is less enthused. Regardless, warm w/SW flow around an Atlantic high will bring well above average temperatures through mid week, though those along the immediate south coast will see much cooler temps thanks to air off the cold ocean. The increasing warmth raises concerns for rises on rivers and streams as we quickly lose our snowpack. Ensemble guidance continues to indicate a 20-40% probability of minor river flooding as early as Mon-Tue. As we get closer and have more high resolution guidance we`ll also have to nail down how far south a backdoor cold front may sink late Tuesday into Wednesday which would put a damper on warm temperatures for at least northeast MA if not areas further south and west. The next shortwave disturbance and cold front arrives by the end of the week bringing cooler and wetter weather. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 12z TAF Update... Today...High confidence. IFR/LIFR conditions dominate today and tonight. Lingering -DZ and localized -FZDZ which was mainly in the high terrain will come to an end by mid morning. Otherwise...surface winds shift to the SSW at 8- 15 knots with some 20+ knot gusts today. This may allow cigs/vsbys to improve very slightly to IFR levels in some locations away from the south coast later today and into tonight. However...LIFR conditions will be favored near the south coast where advection fog perhaps even dense at times will impact areas near the south coast, Cape and Islands. Tonight...High confidence. A band of of showers will approach western MA/CT after 03z/04z tonight and may reach the coastal plain 06z/07z. While the showers will be undergoing a weakening trend...they still may survive in some form and reach the coast. Perhaps even an isolated rumble of thunder. S-SW winds will gust between 15 and 25 knots. We also will have LLWS in the TAFS given an 850 mb southwest LLJ on the order of 55-70 knots. Sunday...High confidence in trends with moderate confidence in timing. Gradual improvement will occur on Sunday with many locations eventually improving to VFR by mid afternoon...except for areas near the south coast, Cape & Islands where low clouds and fog may persist. SW winds should shift to the W at 10 to 15 knots. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Sunday through Wednesday/... Sunday: Mainly VFR, with local IFR possible. Breezy. Slight chance RA, patchy BR. Sunday Night: VFR. Monday: VFR. Breezy. Monday Night through Tuesday: VFR. Tuesday Night: Slight chance RA. Wednesday: Breezy. Chance RA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today through Sunday...High confidence. Lingering small craft swell will require headlines across our outer- waters through the weekend. In addition...shortwave/warm front will result in a period of southwest wind gusts of 20 to 30 knots tonight into Sunday morning for most of our waters. Therefore...we have additional small craft headlines for all our open waters over this time. Lastly...areas of fog and poor visibility will be an issue for mariners the entire weekend especially near the south coast. Outlook /Sunday through Wednesday/... Sunday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Chance of rain, patchy fog. Areas of visibility 1 nm or less. Sunday Night: Winds less than 25 kt. Seas up to 5 ft. Monday through Monday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Tuesday through Tuesday Night: Winds less than 25 kt. Wednesday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of seas approaching 5 ft. Chance of rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 6 PM this evening to noon EST Sunday for ANZ231>235-237. Small Craft Advisory until 7 PM EST Sunday for ANZ250-251- 254>256. && $$