


Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
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996 FXUS61 KBOX 082300 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 700 PM EDT Fri Aug 8 2025 .SYNOPSIS... High pressure will bring warm days and comfortably cool nights through Saturday night. Warming trend begins in earnest Sunday as strong mid-level ridging builds over the region. Extended period of warm weather likely continues through at least Thursday. Temperatures away from the south coast will increase to 90 plus. Unsettled weather returns later in the weak as the ridge begins to break down. && .NEAR TERM /THROUGH SATURDAY/... Tonight: High pressure remains anchored overhead tonight, bringing another gorgeous evening with comfortable humidity. Dewpoints are once again in the upper 40s to low 50s across the region this afternoon. Given low temperatures last night fell to afternoons dewpoints, expecting lows to once again fall to the upper 40s to low 50s with clear skies. Skies may cloud over near the south coast tonight, as light southerly flow and saturated air will be conducive for the formation of low stratus and fog. && .SHORT TERM /SATURDAY NIGHT/... Saturday and Saturday night. Another rinse and repeat weather day as high temperatures warm in the low to mid 80s with comfortable humidity as dewpoints remain below 60F. Winds remain light out of the SSE with localized sea breezes along the coasts. Overnight lows stay slightly warmer Saturday night, but still drop into the 50s away from urban centers and coasts. Low stratus and fog are possible again, mainly near the south coast. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Key Messages: * Multi-day streak of above average temperatures still likely starting Sunday * A few showers or t-storms possible mid-late week, but dry pattern overall Guidance remains consistent in showing a building upper level ridge and surface high pressure across the eastern CONUS. Moderate to high confidence in an extended period of 90+ degree temperatures starting Sunday and lasting through Thurs. Confidence in heat-related headlines is somewhat lower with this update as lower dewpoints may keep most locations from seeing heat index values above 95 degrees. Still, the extended stretch of above normal temperatures will pose a risk for those without access to proper cooling and to those working outdoors. Confidence in the upper air pattern decreases late in the week given spread among deterministic guidance regarding whether the ridge will break down. High confidence in the forecast through Wed then decreasing confidence. NBM still showing 60-85% probs of 90+ next week away from the immediate coast. The worst of the heat is expected in the interior as daily sea-breezes may temper the heat somewhat near the coast, especially the south coast. It appears humidity levels will be moderate through at least Tue and possibly Wed with dewpoints mostly in the low-mid 60s which would keep heat indices a bit below dangerous thresholds. The lower dewpoints will also allow overnight low temps to fall into the 60s through mid week. The probability of dewpoints approaching 70 increases Wed and especially Thu as higher PWATs develop. Dry weather expected through at least Tue with subsidence and limited instability in place. While moisture and instability increases later Wed-Thu, synoptic forcing remains weak. Risk for diurnal showers/t-storms will increase somewhat Wed and especially Thu as instability increases. Greater chance for more organized convection Friday as a cold front pushes into the region. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 00z TAF Update: Overall high confidence. VFR area wide and those conditions will continue overnight and through Saturday and into Saturday night as well. Guidance does suggest the potential for patchy fog across parts of the CT River Valley in northern MA, eastern CT, RI and into SE MA overnight. Perhaps Taunton/TAN and Plymouth/PYM airports have a brief period of MVFR/IFR, but TAF sites are expected to remain VFR. Overall light surface winds that tend to be SE/S across the region, but will see onshore sea breezes develop by late Saturday morning along the MA east coast. Skies will remain clear Saturday, outside of a shallow daytime cumulus cloud well inland. Saturday night should be similar to tonight (ie: VFR with very patchy fog) KBOS terminal...High confidence in TAF. Sea breeze will diminish 01-02z this evening, and return Saturday morning between 13-14z. KBDL terminal...High confidence in TAF. Outlook /Sunday through Wednesday/... Sunday through Monday Night: VFR. Tuesday: VFR. Breezy. Tuesday Night: VFR. Wednesday: VFR. Breezy. Slight chance SHRA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Through Saturday Night...High confidence. Tranquil boating conditions expected to continue through Sat night with E- SE winds 15 kt or less. Seas 3 ft or less all waters. Outlook /Sunday through Wednesday/... Winds less than 25 kt. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...KP/FT NEAR TERM...KP SHORT TERM...KP LONG TERM...FT AVIATION...KP/Nash MARINE...KP/FT