Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
045 FXUS61 KBOX 101847 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 247 PM EDT Mon Aug 10 2026 .WHAT HAS CHANGED... Forecast remains on track. && .KEY MESSAGES... - Above normal temperatures and humidity continues through Tuesday. Relief from the heat & humidity comes late week and especially this weekend. - Unsettled weather continues this week with shower and thunderstorms chances returning this evening as well as Wednesday night/Thursday morning. && .DISCUSSION... KEY MESSAGE 1...Above normal temperatures and humidity continues through Tuesday. Relief from the heat & humidity comes late week and especially this weekend. A bit of a persistence temperature forecast to start the week as the pattern is overall pretty zonal. Model soundings indicate mixing up to near 850 mb where temperatures are/will be hovering around 16C resulting in highs in the upper 80s, perhaps touching 90s in the warmest spots today and Tuesday. We`ll then see a gradual cooling down through the work week and especially by the weekend. 850 mb temps drop to near 13C by mid week leading to highs in the upper 70s (high elevations) to mid 80s. The weekend, though, looks quite comfortable as dewpoints which will be elevated at times through the week but never oppressive, really drop by the weekend into the upper 40s to low 50s! This leads to the chance for some cooler nights in the 50s while afternoon temps may not make it out of the 70s for many locations. KEY MESSAGE 2...Unsettled weather continues this week with shower and thunderstorms chances returning this evening, as well as some time from late Wednesday night into Thursday night. Looking at a rather narrow time window for thunderstorms this afternoon, pretty much from 5-9 PM. Most-unstable CAPE values peak about 750-1,100 J/kg during this time, then quickly diminish after sunset. There is just not enough synoptic forcing to maintain it much longer. While a few thunderstorms are possible after sunset, they should be weakening as they move across southern New England, especially by the time they reach eastern MA. Anticipating the majority of the stronger convection over PA and NY state to remain mainly to our south and west. Will continue to monitor this though as it could remain somewhat as potent moving into the CT River valley. Tuesday and Wednesday should remain dry and mostly sunny with more comfortable humidity. Complicated forecast from late Wednesday night into Thursday night. Expecting a frontal boundary to meander across southern New England. Thus, the timing is not well known. This front should provide a trigger for some showers at times, but it should not be a washout. A high pressure should finally get close enough on Friday to push this front offshore, and return drier and cooler weather into early next week. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18z TAF Update: This afternoon: Generally high confidence, but moderate confidence on timing/probability of TSRA. VFR with hazy skies from high level smoke possible. Winds SW 5-10 kts. SHRA/TSRA look to develop late in the day, starting as soon as 21z at BDL with the higher risk after 23Z. Confidence decreases in TSRA as the activity moves E/ESE toward ORH and further east terminals (00-05Z). Tonight: High confidence. VFR. Sea breeze at BOS kicks out 23-01Z with winds shifting to SW. SW winds 5-10 kts shift to WSW/W overnight. Tuesday: High confidence. VFR. NW winds 10-15 kts. Tuesday night:High confidence. VFR. Winds light and variable. KBOS Terminal...Moderate confidence in TAF. Low probability for a SHRA/TSRA after 01-06Z. Too low to include in TAF at this time. KBDL Terminal...Moderate confidence in TAF. Wildfire smoke aloft possible. Potential for scattered SHRA or a TSRA after 21z, but moreso after 23Z. If any storms develop, a stronger storm is possible with gusty winds, frequent lighting, and brief IFR visbys. Outlook /Tuesday Night through Saturday/... Wednesday through Wednesday Night: VFR. Thursday: VFR. Breezy. Chance SHRA. Thursday Night: Mainly VFR, with local IFR possible. Chance SHRA. Friday through Friday Night: VFR. Breezy. Saturday: VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Through Tuesday night... High Confidence. Winds becoming SW 10-15 kts. Becoming W after 06z. Local sea breezes along the east coast of MA Monday. Seas 1 to 3 feet. Outlook /Wednesday through Saturday/... Wednesday through Wednesday Night: Winds less than 25 kt. Thursday: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers. Thursday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers. Friday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers. Friday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Saturday: Winds less than 25 kt. Seas locally approaching 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ DISCUSSION...Belk/BW AVIATION...Belk/BW MARINE...Belk/BW