Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
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197 FXUS61 KBOX 140529 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 129 AM EDT Tue May 14 2024 .SYNOPSIS... A warm front brings widely scattered showers tonight followed by much warm weather tomorrow, a couple of showers and/or an isolated thundershower are possible in the interior Tuesday afternoon. Unsettled weather Wednesday through the weekend with more clouds than sun and periods of rain. Seasonable temperatures through the upcoming weekend. && .NEAR TERM /THROUGH TODAY/... 930 PM Update... Shower activity attempting to encroach on western MA and eastern NY is having a tough time reaching the surface with dewpoint depressions between 10-15F. Dewpoint depressions will shrink overnight which will likely allow some light shower activity to skirt north of the MA Turnpike before daybreak. Cloud cover is significantly less than forecast across the CT River Valley per satellite, which may aid a bit in dewpoint depressions collapsing over the next few hours, though S/SW winds are just strong enough to stave off significant radiational cooling. We`ll see if this translates to slightly more widespread shower activity, but for now, kept forecast PoPs as is. Previous Update... Update: 3PM Overall a stunner of an afternoon with many enjoying a sun-filled afternoon while others are stuck beneath diurnal cumulus which developed along the sea-breeze boundary. As these diurnal clouds wane this afternoon, mid and high clouds increase from the west ahead of a warm front. Stepping outside this evening should enjoy temperatures in the low 60s and falling into the upper 50s shortly after sunset. 850mb jet advects higher PWATs between 1.0 and 1.3 inch tonight and with the warm front passing through a few showers possible, though the best forcing looks to be limited to northern Massachusetts and points north into Vermont & New Hampshire. No washouts are expected, QPF is in the neighborhood of a few hundredths of an inch. South to southwest winds overnight are less than 10 mph. Nighttime lows are on either side of 50 degrees. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... Update: 3PM A warm and summer-like head is on tap! With the passage of the warm front Monday night, we are placed in the warm sector. Clouds from overnight do linger across northern Massachusetts, but will give way to partly sunny skies and fairly mild temperatures. Deep southwest flow usher in warmer and a more humid air mass. 925mb temperatures climb to +14C to +18C and BUFKIT shows a well mixed boundary layer tomorrow, highs will easily climb into the middle 70s away from the coast. It`s not out of the question a few spots like the Merrimack and Connecticut River Valley top out around 80 degrees. Back to the coast, the southwest flow is an onshore wind for coastal Rhode Island and southeast Massachusetts, here the temperature Tuesday afternoon only reaches the upper 60s and low 70s. Southwest winds become gusty as well, 15 to 25 mph. Shower are limited to northwest Massachusetts during the late afternoon where the best moisture and instability are located. HREF ensembles have roughly 500-1000 units of MUCAPE along and west of the Berkshires, so it`s possible there may be an iso. non severe thunderstorm. Rain chances expand throughout the overnight hours with a mid-level trough and frontal boundary approaching from the west. Winds ease overnight becoming more south less than 10 mph. Night lows fall into the middle and upper 50s. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Update: 3PM Highlights * Unsettled weather Wednesday through the weekend with more clouds than sun and periods of rain * Seasonable temperatures through the weekend Wednesday and Thursday A coastal low pressure system will pass well south of southern New England during the day Wednesday. Nonetheless, modest synoptic forcing and PWATs greater than 1 inch should support periods of rain during the day Wednesday. Accumulations will be modest with the strongest forcing to our south, but somewhere between 0.1 and 0.25 inches between Wednesday and Thursday morning should be in the cards for portions of southern New England. Downstream blocking has resulted in model guidance trending toward a slower departure of this system with cloud cover and showers lingering into the first half of Thursday for much of the forecast area. A mid-level ridge building in from the west may salvage a partly sunny day for the western areas on Thursday afternoon. Expect somewhat gusty southwest winds on Wednesday with northeast gusts along the east coast on Thursday. Friday through the weekend The forecast remains unsettled late week through the weekend. As the mid-week coastal low departs over the Atlantic Friday afternoon, a short-wave dropping down from The Great Lakes will support the development of another surface low-pressure system that is likely to bring cloudiness and periods of rain to southern New England this weekend. Confidence in timing, duration, and intensity of potential rainfall is low at this time so we have leaned on the NBM for guidance at this time range. Temperatures look to be seasonably persistent through the weekend with daily lows in the low to mid 50s and daily highs ranging from the low 60s to low 70s. Coastal locations continue to run cooler with highs in the upper 50s/low 60s more common on days with onshore flow. && .AVIATION /05Z TUESDAY THROUGH SATURDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06Z TAF Update Tonight...High confidence. VFR. Scattered showers are possible across northern MA, with at times briefly lower VFR CIGs 3-5k ft. Winds are south to southwest 5 to 10 knots. Today...High confidence. VFR. Very isolated showers through 12Z, generally north of the MA Turnpike, resulting in little more than a wet runway. Dry through mid day before the chance for isolated shower/thunderstorm redevelops after 22Z in far western MA. Most terminals will remain dry through the duration of the day. Steady southwest winds with gusts developing in the afternoon 20 to 25 knots. Tonight...High confidence. VFR with lowering cigs to around 4000-5000ft in western MA/CT by daybreak where isolated showers are possible. Winds remain persistent from the S/SW overnight. Wednesday... Moderate Confidence Tricky forecast Wednesday with low pressure to our south, but drier trend has developed. Generally VFR with pockets of MVFR. Isolated shower chances persist for western MA/CT but a mix of sun and clouds for eastern terminals. Showers associated with low pressure will remain south until early evening but may impact Cape/Islands/srn RI terminals by 00Z. S/SW winds shift to the SE. KBOS TAF...High confidence in TAF. VFR. Isolated shower chance before 12Z this morning. Breezy southwest winds with gusts 20 to 25 knots fend off any sea- breeze potential on Tuesday. KBDL TAF...High confidence in TAF. VFR. Increasing wind speeds Tuesday with gusts 20 to 25 knots possible. Isolated shower chances late this evening. Outlook /Wednesday Night through Saturday/... Wednesday Night: Mainly VFR, with local IFR possible. Breezy. Chance SHRA. Thursday: Mainly VFR, with local MVFR possible. Windy with local gusts up to 30 kt. Chance SHRA. Thursday Night: VFR. Breezy. Chance SHRA. Friday: VFR. Breezy. Slight chance SHRA. Friday Night: VFR. Chance SHRA. Saturday through Saturday Night: Mainly VFR, with local IFR possible. Chance SHRA. Sunday: Slight chance SHRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Update: 3 AM Through Wednesday.... S/SW winds persist through Tuesday night before shifting to the SE Wednesday afternoon. Gusts to 25kt possible this afternoon for our far NE waters, resulting in a short fused small craft advisory. Generally dry on Tuesday with isolated shower chances for the eastern waters this morning. Shower chances increase for the southern waters late Wednesday as low pressure creeps north from the mid- Atlantic coast. Outlook /Wednesday Night through Saturday/... Wednesday Night: Winds less than 25 kt. Local rough seas. Chance of rain showers. Thursday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Chance of rain showers. Thursday Night: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Chance of rain showers. Friday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain showers. Friday Night: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers. Saturday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain showers. Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers. Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Dooley/RM NEAR TERM...Dooley/KS SHORT TERM...Dooley LONG TERM...RM AVIATION...KS MARINE...Dooley/RM