Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
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552 FXUS61 KBOX 080536 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 136 AM EDT Sat Jun 8 2024 .SYNOPSIS... Cooler tonight, then mainly dry and seasonable conditions Saturday. Scattered showers on Sunday with diminishing rain chances through Tuesday. Warming and drying trend Wednesday and Thursday, before unsettled conditions return to round out the weekend. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 10 PM update... Scattered showers moving across SNE this evening, supported by mid level shortwave and pronounced cooling aloft. Some marginal instability but this is all below a strong mid level cap which is limiting vertical growth. Expect a few showers to move into central and eastern MA during the next few hours. Mainly dry conditions after midnight but still can`t rule out an isolated shower overnight as core of coldest air aloft settles over the region 06-12z. Stratus and patchy fog impacting the Cape/Islands. Vsbys have improved but probably won`t see much clearing of the low clouds until after 06z when winds shift to W behind the weak cold front. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... Trending less humid for Saturday, but still the low risk for a spot afternoon shower. The greater risk will be towards northern New England. A stronger west wind should keep the seabreeze at bay, meaning high temperatures along the immediate east coast. Clearing for a brief time Saturday night. More clouds and a risk for showers could arrive late Saturday night ahead of another weak low pressure. Above normal temperatures continue. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Highlights * A mix of showers and sunshine on Sunday * Some spot showers possible Monday/Tuesday before what looks to be a drying trend mid week * Unsettled conditions possibly return late next week with trough developing in the vicinity of the northeast Sunday... Sunday is shaping up to be the wettest day of the long term period with cutoff low quasistationary in southern/central Quebec. Southwest surface to 925mb flow will allow PWATs/dewpoints to surge back above 1.25"/mid 60s. More robust shortwave, at least compared to what we`ve seen the last few days, will scoop across the northeast beginning Sunday morning, but is rather slow to move seaward so should produce showers for the better part of the day. Still, the day doesn`t look like a washout, but anyone with outdoor plans may want to pack an umbrella. Thunderstorm potential remains low on Sunday with modest CAPE, between 400-600J`kg, but as is often the case here in SNE, mid level lapse rates are lackluster, perhaps just touching 6.5C/km. So, while we can`t rule out a few rumbles of thunder in the strongest cold pool convective showers, we do not anticipate severe weather. Monday and Tuesday... Upper level cutoff shifts northeast of the region to start the work week, but lagging shortwave trough will yield scattered shower activity for Monday and Tuesday, particularly across northern Massachusetts, with lingering cold pool aloft (850mb temps may drop as low as 0C across upstate NY late Monday). Cold pool showers will be fighting against a drying column as PWATs again drop to 0.75", so overall expect shower activity to be much more sparse compared to Sunday. Expecting more sun than clouds both days with diurnal cumulus developing each afternoon. Even with cold pool aloft, W/NW downsloping should support temperatures slightly above to near normal, in the mid to upper 70s, perhaps touching 80F in the warmest locations. Mid to Late Week... Very persistent trough/cutoff upper low finally relinquishes its grasp on southern New England by Wednesday as ridging builds in from the southwest. There remains uncertainty in how strong ridging will be, but it should provide a brief lull in unsettled conditions as high pressure settles in the vicinity of the region through Thursday. Temperatures also look to trend in a warmer direction as we progress through the week as southwest winds develop behind the departing trough. Global guidance shows another trough sliding southeast from the Great Lakes/southern Ontario to round out the work week/start next weekend, but remains varied in timing and strength of the feature. So, while it looks like unsettled conditions will return by Friday/Saturday, specific details won`t be sussed out for several days. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06z TAF update... Through 12z... VFR. Patchy IFR stratus and fog over outer Cape will improve to VFR by 07z. Today...High confidence. VFR. Sct-bkn cu around 5k ft developing 14-17z with a brief shower possible, mainly north of the MA Pike. W wind gusts to 25-30 kt developing by midday, winds more SW over Cape/Islands. Tonight...High confidence. VFR, with lowering cigs late across interior MA and CT as showers move in from the west. W-SW wind 5-10 kt. Sunday...Moderate confidence. Areas of MVFR cigs developing as a period of showers move across the region. Mostly SW wind 5-15 kt. KBOS TAF...High confidence. KBDL TAF...High confidence. Outlook /Sunday Night through Wednesday/... Sunday Night: Mainly VFR, with local MVFR possible. Breezy. Chance SHRA. Monday: Mainly VFR, with local MVFR possible. Breezy. Slight chance SHRA. Monday Night: VFR. Tuesday: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Tuesday Night: VFR. Wednesday: Mainly VFR, with local MVFR possible. Slight chance SHRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. High confidence through Saturday. SW to W winds develop overnight. Before that happens, areas of poor visibility in fog around the Cape and islands. Improving visibility late tonight through Saturday night. A few gusts up to 25 kt possible Saturday afternoon. Otherwise, expecting seas to gradually subside tonight. Small Craft Advisory continues for marginal 5-foot seas across the outer southern coastal waters. Outlook /Sunday Night through Wednesday/... Sunday: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers. Sunday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers. Monday: Winds less than 25 kt. Seas locally approaching 5 ft. Monday Night: Winds less than 25 kt. Tuesday: Winds less than 25 kt. Slight chance of rain showers. Tuesday Night through Wednesday: Winds less than 25 kt. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 5 AM EDT early this morning for ANZ255. && $$ SYNOPSIS...Belk/KS NEAR TERM...KJC SHORT TERM...Belk LONG TERM...KS AVIATION...KJC/KS MARINE...Belk/KS