083 FXUS61 KBOX 050818 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 318 AM EST Wed Nov 5 2025 .SYNOPSIS... Dry and seasonably mild conditions today with increasing SW winds, then a strong cold front generates fast-moving gusty showers and possibly thunderstorms this evening. Behind the front strong to damaging wind gusts will develop late this evening and overnight gradually diminishing during Thursday. High pressure builds into the region Thursday night and moves offshore Friday. Weather pattern turns unsettled next weekend as a series of frontal systems move through, followed by blustery and colder weather early next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 300 AM Update: Key Messages: * Mostly clear to start. While dry weather prevails, turning overcast with canopy of mid-level cloud cover by late morning. * SWly breezes to around 20-25 mph today. Seasonable temps in the 50s, near 60 in some spots. Details: Ridge of sfc high pressure is in place over Southern New England early this morning, with initially clear skies and a modest SW wind. Current temps varied pretty widely but were as low as the low 30s in interior Southern New England but in the mid 40s for eastern MA/coastal areas where SW winds were around 5-10 mph. To our west, infrared satellite was showing considerable midlevel cloud cover over central and southern NY associated with midlevel moist advection in a belt of fast westerly flow aloft, extending out well ahead of an organizing low pressure area over WI. Dry weather is expected today, but conditions should trend overcast by the mid-morning to noontime period as this midlevel moisture advects eastward into our area. This will allow for slow diurnal warming. A steadily-tightening southwest pressure gradient will also permit increasing southwest breezes, with shallow mixing allowing for gusts in the 20-25 mph range as we move into the aftn. Highs in the 50s today, but a few areas in CT-RI-SE MA could still see temps near 60 degrees. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... 230 AM Update: Key Messages: * Fast-moving line of gusty showers and embedded thunderstorms capable of isolated/sporadic wind damage between 7 pm to midnight from the Berkshires to the east coast. * Drying out after midnight, but with a period of strong to damaging northwest wind gusts in the 55 to 60 mph range for overnight into early Thurs AM. Downed trees and powerlines in scattered instances with this period of northwest winds. * Sunny and still windy for Thursday, but gusts to steadily decrease after mid-morning Thursday. Highs in the 40s to mid 50s, though winds will make it feel colder than that. Details: Potent mid/upper level shortwave with associated strengthening sfc frontal wave will be moving through the Gt Lakes, northern New England and offshore tonight and overnight. Its passage through the Northeast will bring a couple of anticipated hazards to Southern New England: the first being a fast-moving line of low- topped convective showers/embedded thunderstorms through midnight in lockstep with a strong cold frontal passage, and then a period of post-frontal strong to damaging northwest wind gusts for the overnight to early Thurs AM hours. Model guidance trends from the overnight suite drove wind- headline changes. Compared to the last 24-hours worth of guidance, the post-frontal northwest wind gusts doesn't look quite as robust with slightly-less amplification to the sfc low, and speeds at the top of the mixed layer being about 5-kt lower. Weighing that trend, I only felt sufficiently confident enough to convert the standing High Wind Watch over to High Wind Warnings for the east slopes of the Berkshires and the Cape and Islands, where post-cold-frontal northwest wind gusts up to 60 mph are expected. For the rest of Southern New England, the high wind watch was maintained given the slightly less-robust trend from overnight. Later shifts today will need to make a decision on the status of the remaining High Wind Watch pending the incoming 12z guidance. That still allows for sufficient lead- time. Without question, some headline will be needed to address the strong northwest winds. 1/ Cold Frontal Gusty Showers/Thunder Before Midnight Pretty classic strongly-forced, high-shear but very low instability convective pre-frontal setting tonight thru midnight. Convective- permitting models continue to show a broken line or clusters of gusty convective elements. Not much instability to really speak of with CAPE values around 200 J/kg or less, but model soundings show enough CAPE around -10C to support a risk for lightning in some of the cells. In addition, Southern New England looks primed for added kinematic support placed in the poleward exit region of an impressive 120-kt jetstreak at 500 mb, similar to the event which happened Monday night. While no two events are truly ever 100 percent matches, some of the main synoptic features (digging shortwave, diffuent flow aloft) also bear some similarities to an early-October 2020 high shear low CAPE thunderstorm event as well, though that took place more during the later-afternoon hours. Timing this threat looks to be around the 7 pm to midnight timeframe from the Berkshires eastward to the coast. It's also worth noting that these gusty showers/storms are likely to be hauling eastward, given 50-55 kt storm motion vectors. It wouldn't entirely shock me if we do hear of sporadic wind damage associated with these showers/t-storms, before the northwest winds really pick up for the overnight. SPC maintains low probabilities for severe weather conveyed by a marginal risk of severe weather. 2/ Strong to Damaging Winds Overnight to Early Thursday We then get into the strong cold advection period after the cold front works its way offshore, which will help to steepen lapse rates overnight. Working in concert with 6-8 mb per 6 hr pressure rises, a period of strong to damaging winds are still expected. With a 60-65 kt NW jet at 850 mb over the Berkshires, and then the Cape and Islands as the low starts to really amplify towards the wee hours of the morning, felt high wind criterion would be most likely to be met for those areas, peak gusts for these areas have the potential to reach 60 mph. Elsewhere, with 55-60 kt at 850 mb, felt gusts could be close enough to advisory level (50 to 55 mph) to wait another model cycle before making changes to the Watch. The period of strongest gusts also just takes place for a handful of hours, before the jet starts to weaken/pull eastward into early Thursday morning. Thursday itself still ends up being a rather windy day with full sun allowing for a continued deepening mixed layer, but northwest wind gusts more clock in around 25-40 mph in gusts. Note that daytime highs in the mid 40s to low 50s, which will feel even colder given the winds, with wind chills around the freezing mark for the higher terrain during the day. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Key Messages: * Initially zonal and progressive pattern becomes increasingly amplified by early next week. * Multiple chances of precipitation with bouts of drier weather in between. * Above average temperatures to end the week, potential for significantly cooler conditions early next week. The theme of the long term forecast will be for the upper air pattern to progress from a zonal regime late this week into a more meridional and amplified regime early next week. In terms of sensible weather impacts, this evolution will lead to a period of changeable weather Fri-Sun followed by much cooler conditions early next week. Expecting a cold night Thursday behind a deepening northern stream system. NBM shows rapid clearing and decreasing winds allowing for lows to fall below freezing outside of the Cape and Islands. Cool spots in the higher terrain may even fall into the mid and lower 20s by early Friday morning. Strong return flow behind a quick moving area of high pressure warms 850 mb temps from -negative 3-5C Friday morning to +5-8C Friday evening. This sharp increase in mid-level temperatures will translate 10-15 degree warmer low temps Friday night. Continued WAA brings increasing cloud cover and increasing POPs later Friday into Saturday. A slow-moving frontal boundary serves as the forcing mechanism for periods of rain on Saturday as PWATS increase to 1.5-2 STD above climo. Not seeing too much of a signal for excessive rainfall amongst the ensembles with the NBM showing 24hr precip totals generally below 1". Transient ridge of higher pressure makes a return again to dry the region out briefly Saturday night into Sunday. Attention then turns to a deepening and anomalous upper-level longwave trough over the eastern CONUS in response to a building upper level ridge over the west. Guidance depicts an area of low pressure developing ahead of the trough on Sunday followed by a strong cold front later Sunday into Monday. We may see our first bonafide shot of colder air Monday and Tuesday of next week as guidance has 850s falling to as low as minus 10-15C. An early glimpse at forecast temperatures for next week shows highs struggling into the lower to mid 40s behind the front on Tuesday. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06z TAF Update: Through 12z Wednesday: VFR. WNW wind gusts 35-40 kt dropping off by 21z. Tonight: High confidence. VFR. WNW gusts to 25-30 kt Cape/Islands early diminishing and becoming light overnight. Wednesday: High confidence. VFR, with increasing mid-high clouds. Wind becoming SW 10-20 kt in the afternoon, with gusts to 30-35 kt developing along the south coast and Cape/Islands by late in the day. Wednesday night: High confidence. VFR-MVFR cigs with brief scattered showers and possibly an isolated t-storm during the evening, then clearing overnight. Wind shift to WNW 03-06z with cold front passage followed by strong wind gusts to 50-55 kt, possibly as strong as 60 kt Cape/Islands. KBOS Terminal... High confidence. KBDL Terminal... High confidence. Outlook /Thursday Night through Sunday/... Thursday Night through Friday: VFR. Breezy. Friday Night: MVFR/IFR conditions possible. Windy with local gusts up to 30 kt. RA likely. Saturday: Mainly VFR, with local MVFR possible. Breezy. Chance RA. Saturday Night: VFR. Slight chance RA. Sunday: Mainly VFR, with local MVFR possible. Breezy. Chance RA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Key Messages: * Increasing SW winds today reaching gale force over southern waters toward evening. * Possible line of gusty showers capable of lightning could prompt special marine warnings or marine weather statements late this evening. * Widespread storm force winds overnight to early Thurs after wind shift to W-NW. Gusts 50-60 kt. Storm warnings remain in effect for all waters. SW winds will be steadily increasing today to around 25 to 30 kt and trending toward gale force SW gusts late in the day today. Dry weather prevails, although a line of gusty showers with embedded lightning strikes associated with a strong cold front later this evening could prompt MWSs/SMWs. Windshift to NW late tonight and overnight will bring a period of widespread storm-force gusts 50-60 kt into Thurs AM with building and rough seas in the 13-16 ft range. A gradual decrease in gusts into into the 35-40 kt range by Thurs aftn then trending toward 25-30 kt gusts by early evening. Outlook /Thursday Night through Sunday/... Thursday Night: Low risk for Small Craft Advisory winds with local gusts up to 30 kt. Local rough seas. Friday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Seas locally approaching 5 ft. Friday Night: Strong winds with local gusts up to 30 kt. Areas of rough seas. Rain likely. Saturday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain. Saturday Night: Winds less than 25 kt. Local rough seas. Slight chance of rain. Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...High Wind Watch from this evening through Thursday morning for CTZ002>004. MA...High Wind Watch from this evening through Thursday morning for MAZ003>007-010>021-026. High Wind Warning from 7 PM this evening to 8 AM EST Thursday for MAZ002-008-009. High Wind Warning from 10 PM this evening to 8 AM EST Thursday for MAZ022>024. RI...High Wind Watch from this evening through Thursday morning for RIZ001>008. MARINE...Storm Warning from 10 PM this evening to 7 AM EST Thursday for ANZ230-233>237. Storm Warning from 10 PM this evening to 10 AM EST Thursday for ANZ231-232-250-251. Storm Warning from 7 PM this evening to 10 AM EST Thursday for ANZ254-255. Storm Warning from 7 PM this evening to 7 AM EST Thursday for ANZ256. && $$ SYNOPSIS...Loconto/FT NEAR TERM...Loconto SHORT TERM...Loconto LONG TERM...FT AVIATION...Loconto/FT MARINE...Loconto/FT