


Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
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919 FXUS61 KBOX 041501 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 1101 AM EDT Mon Aug 4 2025 .SYNOPSIS... An extended stretch of dry weather with seasonable temperatures and tolerable levels of humidity is anticipated for most of this week. Our next chance for rain may not materialize until next Sunday. && .NEAR TERM /THROUGH TONIGHT/... Key Messages: * Haze from Canadian wildfire smoke * Dry with continued seasonable temperatures and slightly cooler temperatures on the immediate coasts from local sea breezes Continued dry conditions as high pressure dominate our weather pattern. Slightly above normal high temperatures with sea breezes cooling the immediate coasts. Canadian wildfire smoke will continue to move over southern New England, which may have some concentration near the ground in spots. && .SHORT TERM /TUESDAY/... Key Messages: * Haze from Canadian wildfire smoke Seasonable overnight conditions expected again tonight. Some guidance indicates slightly higher relative humidity values aloft overnight, which lines up with expected increasing cloud cover heading into Tuesday morning. No rain expected. Some wildfire smoke lingers tonight into Tuesday, but may not be as noticeable with the increased clouds. Expecting a bit of a cool-down Tuesday across the eastern half of our region. A front sagging south towards southern New England will lead to a synoptic easterly flow. Since this will be off the ocean with water temperatures in the 60s, this will lead to below normal high temperatures. Farther inland, high temperatures should remain slightly above normal. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Key Messages: * Other than low (<20%) chances at showers or t-storms Tue Night-Thu in/around the Berkshires, an extended stretch of dry weather with seasonable temperatures remains in the offing for the first week of August. * Highs mid 80s with lows mid 50s to lower 60s, to go along with cooler seabreezes each day. * Uncertainty increases for late this weekend / early next week due to possible subtropical development off the Carolina coast. Details: Overall, no substantial changes noted in today`s guidance versus yesterday`s in terms of the forecast for much of this workweek into the early weekend. We still anticipate an extended stretch of dry weather with seasonable temperatures and low humidity levels, driven by established high pressure near Nova Scotia. There remains a slight-chance mention of diurnally-driven showers/t-storms over the terrain areas in western/northwest MA Wed thru Thu, but won`t be raining the whole time at these locations. Other than that though, it`s a dry forecast through at least Sat with highs in the mid 80s and lows mid 50s to lower to mid 60s. Dewpoints in the mid 50s to lower 60s to boot too, so humidity levels should be tolerable. Uncertainty then increases into Sunday and early next week, as the ridge in place weakens. Farther southward off the Carolina coast, the NHC is monitoring a couple areas of disturbed weather. One, Tropical Storm Dexter, is expected to pass well to our southeast later this week, as it will be suppressed by the strong Nova Scotia high pressure. Another area of disturbed weather with lower chance at development (up to 30%) is north of the Bahamas and southeast of the Carolina coast. This feature is forecast to drift northwestward towards the Carolina coast and then may recurve NE late in the weekend or early next week. There are some GFS and GEM-based model solutions which bring this system close enough to our southeast in which some effects could be possible, but without a well- defined circulation center, tough to have much confidence in any potential outcome at this time. We`ll continue to monitor this area closely through the workweek but as of now, it`s way too early to pinpoint impacts, if there were to be any at all. For the latest on the tropics, refer to the latest Tropical Weather Outlooks issued by the NHC. If nothing else, it serves as a reminder that we are in the midst of tropical cyclone season. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 15z Update... Today...High confidence. VFR/MVFR(Due to smoke). Light N to NW winds this morning, before sea breezes develop once again. Haze from wildfire smoke could cause some minor visibility impacts through this evening. Tonight...High confidence. VFR. SW winds shift more NE overnight but remain light. Increased cloud cover heading into the morning hours, but ceilings should remain firmly VFR. Tuesday...High confidence. VFR. E to NE winds at 10-15 knots. Minor visby reductions possible due to smoke/haze. KBOS terminal...High confidence in TAF. VFR/MVFR(Due to smoke). Sea breeze kicks in around 16z today and kicks out around 01z tonight. Expecting mild visby reduction today due to near sfc smoke. Smoke concentrations decrease slightly after 01z, but will linger through tomorrow. KBDL terminal...High confidence in TAF. VFR/MVFR(Due to smoke). Light N/NW winds today with near sfc smoke and haze. Winds flip SSW tonight then to the NE towards day break tomorrow. Outlook /Tuesday Night through Friday/... VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Through Tuesday...High confidence. High pressure remains over the waters. A period of relatively light winds and seas with good visibility continues. Outlook /Tuesday Night through Friday/... Tuesday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Wednesday through Friday: Winds less than 25 kt. Areas of seas approaching 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Air Quality Alert until 11 PM EDT this evening for CTZ002>004. MA...Air Quality Alert until midnight EDT tonight for MAZ002>024- 026. RI...Air Quality Alert until midnight EDT tonight for RIZ001>008. MARINE...None. && $$ SYNOPSIS...Belk/Loconto NEAR TERM...Belk SHORT TERM...Belk LONG TERM...Loconto AVIATION...McMinn/KP MARINE...Belk/Loconto