Area Forecast Discussion
Issued by NWS Boston, MA

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951 FXUS61 KBOX 150214 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 1014 PM EDT Fri Jun 14 2024 .SYNOPSIS... Second round of strong to severe thunderstorms expected through early tonight ahead of a dry and pleasant Father`s Day weekend. Several days of excessive heat and humidity are likely starting Tuesday and lasting through next Friday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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10 PM Update: A new area of thunderstorms that formed over the Berkshires is now moving east feeding on the last of the MLCAPE for the day. SPC meso analysis suggest 500-1000J/kg of MLCAPE still exists over central CT and MA, but quickly drops to below 500 J/kg east RI. Not expecting any severe wind gusts with these cells as they are no longer surface based. There will be heavy rain, lightning, and possibly pea sized hail with these cells as they move east. Further south over long island, convection has decayed into steady rain with embedded thunder. This will continue to ride the front east towards the Cape and Islands. Radar does show some messy convection near Cape Cod and the Islands, but has not proven to be strong enough to produce anything more then a couple rumbles of thunder.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... Departing cold front/deep digging shortwave will allow very, at least for June, dry air to filter into the region on NW/N flow tomorrow. PWATs are expected to drop to around 0.4" by 18/21Z Saturday, yielding a gorgeous, comfortable start to Father`s day weekend. Little cloud cover is expected, with dewpoints dropping into the low and mid 40s by early evening. 850mb temperatures between 8-10C will support highs in the mid 70s to low 80s. Radiational cooling will be in play Saturday night. With very dry airmass in place and mainly clear skies overhead, as well as slackening winds, it is quite possible that low temperatures drop into the low to mid 40s across northwestern MA by daybreak on Sunday. Urban heat islands, like Boston and Hartford, will remain our most mild localities, with lows around 60F expected. Temperatures across the coastal plain will fall back into the 50s. This is our last shot of cool air for quite some time as mid level ridging starts to build in to end the weekend. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Key Point: * Several days of dangerous heat/humidity Tue-Fri Big story for next week continues to be likelihood of dangerous heat and humidity starting Tue and peaking Wed-Fri. Ensembles are in very good agreement on building strong upper ridge over eastern U.S. through most of next week which lends increasing confidence. In fact, 500 mb heights nearing 600 dm is something rarely seen in the Northeast and is a very strong signal for record heat. This aligns with EPS and NAEFS Situational Awareness Tables which show several parameters outside of model climatology relating to temperature, signaling potential for a highly unusual event. We`re also seeing fairly high chances of afternoon highs well into 90s Tue-Fri, if not near 100 in some spots. More importantly, daytime heat indices may reach as high as 105 degrees and there will be little relief at night with nighttime heat indices in 70s. Upper ridge also favors dry weather for much of next week, but it`s possible we see widely scattered showers/storms, especially in Thu- Fri timeframe as cold front approaches from Great Lakes. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 00z TAF Update: High confidence (70%) Area of showers/storms moving through eastern MA/RI moves offshore early this evening, but another round of showers with embedded thunder should cross southern New England 02z-08z as cold front pushes through. Expect brief lowering to MVFR/IFR. Otherwise VFR ceilings should prevail through tonight as SW winds veer to W-NW and N overnight, except IFR/LIFR is likely to develop near Cape Cod and Islands. Slow improvement Sat morning with VFR-MVFR ceilings gradually scattering out Sat afternoon as N winds increase to 10-20kt with gusts to 25kt near coast. KBOS TAF...High confidence in TAF (70%). KBDL TAF...High confidence in TAF (70%) Outlook /Sunday through Wednesday/... Sunday through Sunday Night: VFR. Monday: VFR. Breezy. Monday Night through Juneteenth: VFR. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight: Steady light to moderate rain with embedded thunder possible. Winds shift WNW and decrease to 5-10 knots overnight. Seas 2-3 feet. Tomorrow: Rain tapers off in the morning with clearing conditions in the afternoon. Winds turn north and gust 15 to 20mph. Seas 2-4 feet. Tomorrow Night: Clear conditions and generally light winds. Seas around 2-4 feet. Outlook /Sunday through Wednesday/... Sunday: Winds less than 25 kt. Seas locally approaching 5 ft. Sunday Night through Monday: Winds less than 25 kt. Monday Night: Winds less than 25 kt. Slight chance of rain showers. 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...
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CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 11 PM EDT this evening for ANZ250- 254.
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&& $$ SYNOPSIS...KS/JWD NEAR TERM...KP/KS/JWD SHORT TERM...KS LONG TERM...JWD AVIATION...JWD MARINE...KS/JWD CLIMATE...Dooley