Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
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043 FXUS61 KBOX 150732 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 332 AM EDT Sat Jun 15 2024 .SYNOPSIS... High pressure will bring dry and pleasant Father`s Day weekend. Dangerous heat and humidity begin to arrive on Tuesday and peak in the Wednesday through Friday time frame. Near record high temperatures are possible with afternoon Heat Indices between 95 and 105 degrees. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Today Shortwave moves offshore with rising heights and high pressure beginning to build in for the weekend. Showers should come to an end before sunrise this morning with dry conditions expected the rest of today. Clouds will clear from west to east this morning as a very dry airmass fills in behind. Winds turn northerly advecting in cooler air for today with highs only in the upper 70s to low 80s. Humidity will also be noticeably lower with dewpoints dropping into the 40s and 50s. Northerly winds and cold air advection will promote mixing which will allow for gusts of 15 to 20mph today until sunset. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... Tonight Upper level ridge axis and surface high pressure move in overhead. With clear skies, decreasing winds, and dewpoints in the 40s, strong radiational cooling will take place. Overnight lows will drop into the upper 40s to low 50s region wide. NW MA will likely be the coldest with lows in the low 40s. Tomorrow High pressure and dry airmass remain over the region. A passing weak 500mb shortwave will bring some high clouds and filtered sunshine to the region. All in all, Sunday will be another gorgeous day with highs in the upper 70s to low 80s, and dewpoints still in the upper 40s to low 50s. Winds will also be also be light as they turn from northerly to southerly late in the day. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Key Points... * Dangerous Heat & Humidity Tue through Fri * Near Record highs with Heat Indices 95-105 degrees * Mainly dry weather next week outside widely scattered t-storm risk Details... The main story continues to be the expected dangerous heat and humidity in store for much of the region next week. Ensembles continue to be in excellent agreement in an anomalous upper level ridge building across New England. Guidance shows 500 mb height fields approaching 600 dm in our region...which is rarely seen in our part of the country and a strong signal for the potential of record heat. This is also supported by the NAEFS & EPS Situational Awareness tables...which indicates several parameters outside the models climatology. That is a strong indication for the potential of a rare/highly unusual weather event...in this case being heat and humidity. The dangerous heat and humidity arrive Tue across the interior, but appears localized sea breezes/onshore flow may limit the initial risk on the immediate coast. The heat & humidity should peak in the Wed through Fri time frame with the only possible relief along the immediate coast during times of localized sea breezes. Otherwise, ensemble guidance data supports near record highs well into the 90s...perhaps touching 100 degrees in spots. If that were to occur...we would challenge all time record highs for the month of June in spots. Either way though the main story will be several days of dangerous heat & humidity. Afternoon Heat Indices will reach into the 95 to 105 degree range. There will not be much relief at night with heat indices remaining in the 70s. Upper level ridging will keep the vast majority of the upcoming work week dry. That being said...near record high temperatures with modest instability will result in a widely scattered t-storm threat. This risk may increase towards the end of the work week as a cold front approaches the region. So in a nutshell...dangerous heat and humidity is the concern for much of next week perhaps even challenging all time June high temperature records in spots! && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today: Rain ends for eastern terminals before sunrise. VFR with northerly winds at 10-15 knots. MVFR cloud deck could linger for the Cape and Islands into the late morning. Tonight: VFR. Winds remain northerly at 5-10 knots. Fog and low status possible across the islands. Tomorrow: VFR. Winds turn light southerly with localized sea breezes possible. KBOS TAF...High confidence in TAF Rain ends before sunrise this morning, then VFR with gusty northerly winds today at 10-15 knots. KBDL TAF...High confidence in TAF VFR. increasing northerly winds today at 10-15 knots. Outlook /Sunday Night through Wednesday/... Sunday Night: VFR. Monday through Tuesday: VFR. Breezy. Tuesday Night: VFR. Juneteenth: Mainly VFR, with local MVFR possible. Breezy. 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. Today: Rain tapers off in the morning with clearing conditions in the afternoon. Winds turn north and gust 15 to 20mph. Seas 2-4 feet. Tonight: Clear conditions and generally light winds. Seas around 2-4 feet. Tomorrow: Clear conditions and light winds. Seas around 2-4 feet. Outlook /Sunday Night through Wednesday/... Sunday Night through Monday: Winds less than 25 kt. Monday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday through Juneteenth: Winds less than 25 kt. && .CLIMATE... Daily Record High Temperatures... Tuesday, June 18th BOS - 94F (1929) BDL - 95F (1994) PVD - 94F (1929) ORH - 93F (1929) Wednesday, June 19th BOS - 96F (1923) BDL - 95F (1995) PVD - 94F (1923) ORH - 93F (1923) Thursday, June 20th BOS - 98F (1953) BDL - 97F (2012) PVD - 95F (1941) ORH - 93F (1953) Last Day of 100F (or greater) BOS - 100F (07/24/2022) BDL - 100F (07/21/2019) PVD - 100F (07/28/2020) ORH - 102F (07/04/1911) && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Frank/KP NEAR TERM...KP SHORT TERM...KP LONG TERM...Frank AVIATION...Frank/KP MARINE...Frank/KP CLIMATE...Dooley