909 FXUS61 KBOX 050644 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 244 AM EDT Sat Jul 5 2025 .SYNOPSIS... Tranquil weather with low humidity continues today. Very warm temperatures in the upper 80s to lower 90s and rising humidity levels will lead to high heat indices Sunday and Monday. Unsettled weather makes a return Monday night, off and on through much of the week. && .NEAR TERM /THROUGH TONIGHT/... Key Messages... * Dry today with more sun than clouds. Mid level height rises will lead to dry weather as surface high pressure begins to sink to our south. This placement directs light SW winds into SNE, though WAA doesn`t kick in in earnest until Sunday when a trough of low pressure passes in closer proximity. A weak warm front in the mid levels will lead to increasing high clouds during the day, but there will be more sun than clouds, helping push high temperatures up into the mid 80s (lower on the south coast where onshore flow keeps temps in check). Tonight partly cloudy skies should keep radiational cooling from being as much of an issue as Friday night, keeping lows about 10 degrees warmer (in the mid 60s). && .SHORT TERM /SUNDAY/... Key Messages... * Hotter with increasing humidity. The mid level ridge axis crosses New England on Sunday placing us beneath increasingly breezy SW flow. Warm air and and moisture is advected north pumping up both the heat and humidity. So, while it will be breezier, gusting 20 to 30 mph, it will feel much hotter than Saturday. Dewpoints increase from the 50s to the upper 60s while high temperatures make it back into the 90s; highest temperatures will be in the CT and Merrimack valleys while the coolest spots are on the south coast, thanks again to onshore flow. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Key Messages... * Peak of the heat and humidity Monday. * Periodic chances of unsettled weather late Monday through the week. Steering flow becomes rather zonal to start the week keeping warm SW flow around. While no rain is expected during the day, what will be notable is the 70F+ dewpoints that will make it feel very humid outside. A weak shortwave moving through the steering flow around Tuesday with a surface frontal system will bring more clouds heading into Tuesday along with the chance for scattered showers and thunderstorms. It remains difficult to nail down when these periodic bouts of unsettled weather move through, but another trough looks to move through around Thu/Fri. Temperatures are more seasonable after Monday. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06z TAF Update: Today and Tonight: High confidence. VFR. Winds to become SWly around 5-10 kt. There remains a low probability of a seabreezes at BOS and PVD but more than likely that it remains offshore. Light SW winds expected Sat night. Sunday, SW winds increase a bit 10-15 kts with gusts 20 to 25 kts. KBOS Terminal...Moderate confidence in TAF. There is the low probability of a seabreeze, but more likely that it remains offshore. KBDL Terminal...High confidence in TAF. Outlook /Sunday Night through Wednesday/... Sunday Night: VFR. Breezy. Monday: VFR. Breezy. Slight chance SHRA. Monday Night: VFR. Breezy. Chance SHRA, slight chance TSRA. Tuesday: Mainly VFR, with local MVFR possible. Breezy. Chance SHRA, chance TSRA. Tuesday Night: Mainly VFR, with local IFR possible. Chance SHRA, slight chance TSRA. Wednesday: VFR. Slight chance SHRA, slight chance TSRA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Through Sunday: High confidence. Tranquil boating weather conditions through Saturday night. SW winds around 10-15 kt today and tonight. Seas 4 ft or less all waters, and around 1-2 ft nearshore. No obstructions to visibility expected. SW winds increase on Sunday, gusting 20-25 kts, as high as 30 kts on eastern waters. Outlook /Sunday Night through Wednesday/... Sunday Night: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Seas locally approaching 5 ft. Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Monday Night through Tuesday Night: Winds less than 25 kt. Chance of rain showers, slight chance of thunderstorms. Wednesday: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Heat Advisory from 7 AM Sunday to 8 PM EDT Monday for CTZ002>004. MA...Heat Advisory from 7 AM Sunday to 8 PM EDT Monday for MAZ003>007-010>019-026. RI...Heat Advisory from 7 AM Sunday to 8 PM EDT Monday for RIZ001>004. MARINE...None. && $$ SYNOPSIS...BW NEAR TERM...BW SHORT TERM...BW LONG TERM...BW AVIATION...BW MARINE...BW