Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
766 FXUS61 KBOX 031854 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 254 PM EDT Wed Sep 3 2025 .SYNOPSIS... Very pleasant weather continues tonight and Thursday. A warm front may bring a few brief showers to the region very late Thursday night into early Friday morning...followed by warmer and more humid weather Friday afternoon. Warm and humid conditions continue Saturday ahead of a cold front along with the risk of afternoon and evening scattered showers and thunderstorms. Cooler and drier weather returns Sunday and Monday behind the cold front with slightly below normal temperatures. && .NEAR TERM /THROUGH TONIGHT/... Key Messages... * Dry & cool tonight...lows mainly in the 50s with a few upper 40s * Patchy ground fog late tonight in the typically prone locations Details... Tonight... A ridge of high pressure will remain in control of our weather tonight. This will result in mainly clear skies along with light/calm winds bringing another good night of radiational cooling. Overnight low temps should again be in the 50s with some upper 40s possible in the normally coolest low-lying locations. We also expect some late night patchy ground fog to develop in the typically prone locations. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... Key Messages... * Mostly sunny & pleasant Thu with highs upper 70s/lower 80s * A few showers possible very late Thu night * Low temps Thu night in the upper 50s to the lower 60s Details... Thursday... The ridge of high pressure moves east of the region for Thursday. We still expect plenty of sunshine with highs mainly in the upper 70s to the lower 80s...but a few degrees cooler on the very immediate coast. Overall...another very nice day with comfortable humidity is on tap for Thursday. Thursday night... A shortwave and associated mid-level warm front will cross the region Thursday night. This will induce a modest southwest LLJ and a few showers very late Thursday night in the warm advection pattern. The greatest risk for showers very late Thursday night will be across interior southern New England...closer to the better forcing/dynamics. Still may see a few brief showers near the I-95 corridor...but certainly not expecting a washout. It will be noticeably milder than recent nights with increasing cloud cover and low level moisture. Overnight low temps will be mainly in the upper 50s to the lower 60s. Some patchy fog will also be possible. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Key Messages: * Lingering showers from Thursday night into Friday morning possible * Greatest chance for severe weather comes Saturday afternoon/evening * Much cooler, drier into next week following cold front over the weekend Details... A trough sitting over much of the eastern U.S. will be the main driver for the weather over southern New England through the weekend ahead of a cold front ushering in drier, cooler air in Saturday night into next week. Some lingering showers from Thursday night remain possible into Friday morning primarily in western MA into CT. Our main concern turns to Saturday afternoon and evening where there remains a chance for some severe storms primarily west of the I-95 corridor. However, the chance does remain for those storms to make it west of that point. SPC SREF guidance is now reaching this period, and there are probabilities above 50% for favorable dynamics for severe storms over much of the interior, especially with lift coming in from an approaching cold front. The I-95 corridor itself remains right on the line between these decent probabilities and chances around 30%. Mean ensemble PWATs sit around 1.6" and higher for Saturday afternoon and evening, so with this moisture and instability lining up, it may be an impactful afternoon period. Once this front passes, cooler and drier conditions will prevail across the region for the second half of the weekend into next week as high pressure also redevelops over the region. Highs are expected to sit in the 70s with overnight lows starting to dip into the 40s outside the urban areas. && .AVIATION /18Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18z TAF Update... This afternoon and tonight...High confidence. VFR continues to dominate...but some fog patches and low clouds may impact the typically prone terminals very late tonight. Winds becoming calm/light SSW tonight. Thursday...High confidence. VFR after any early morning localized fog patches burnoff. Winds becoming S at 7-12 knots with a few gusts between 15 and 20 knots. Thursday night...Moderate confidence. VFR conditions early Thursday evening should deteriorate to MVFR thresholds from west to east overnight from low clouds with the returning low level moisture. Some localized IFR conditions are also possible after midnight across parts of the interior. In addition...a few more advection showers possible late with the greatest risk across interior southern New England. S winds 5 to 10 knots. KBOS Terminal...High confidence in TAF. Sea breeze should end in the 00z to 02z time frame. KBDL Terminal...High confidence in TAF. Outlook /Friday through Sunday/... Thursday Night: Mainly VFR, with local IFR possible. Breezy. Chance SHRA, patchy BR. Friday: VFR. Breezy. Slight chance SHRA. Friday Night: VFR. Breezy. Saturday: Mainly VFR, with local MVFR possible. Breezy. Chance SHRA, slight chance TSRA. Saturday Night: Mainly VFR, with areas MVFR possible. Breezy. SHRA likely, slight chance TSRA. Sunday: VFR. Chance SHRA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight through Thursday night...High confidence. Winds/seas should generally remain below small craft advisory thresholds through Thursday night. However...high pressure moving east of the region Thu into Thu night will allow for some S wind gusts in the lower 20 knots and choppy seas. However...still thinking winds/seas will generally be below small craft advisory thresholds. Outlook /Friday through Sunday/... Thursday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers, patchy fog. Local visibility 1 to 3 nm. Friday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of seas approaching 5 ft. Friday Night: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Seas up to 5 ft. Saturday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain showers. Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Rain showers likely. Sunday: Winds less than 25 kt. Chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Frank/Hrencecin NEAR TERM...Frank SHORT TERM...Frank LONG TERM...Hrencecin AVIATION...Frank/Hrencecin MARINE...Frank/Hrencecin