Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 190733 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 233 AM EST Fri Jan 19 2018 .SYNOPSIS...
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Dry and seasonably cold conditions today, then a warming trend this weekend with continued dry weather. A storm system will bring the potential for heavy rain and strong coastal winds late Monday night into Tuesday, but there is a risk of some wintry mix/ice across the interior late Monday and Mon evening in the interior. Blustery, dry and seasonably cold weather will follow Wednesday and Thursday.
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&& .NEAR TERM /UNTIL 6 AM THIS MORNING/... 130 AM Update... The low clouds that were lingering near E coastal areas and across Cape Cod and the islands are starting to shift E and thin out as seen on latest GOES-16 Nighttime Microphysics composite satellite imagery, while another batch of mid and high level clouds are thinning as they move E across central and northern areas. Still seeing some lower clouds across the Berkshires into upstate NY as the next H5 short wave approaches. Noting some light precip on latest NE regional 88D radar imagery moving across upstate NY, but appears rather poorly organized except from near KART-KSLK. The precip is moving mainly E, so do not expect this to make it into far NW Mass at this point, so have kept a dry forecast for the overnight. With some clouds lingering across central and northern Mass early this morning, as been tough for temps to drop. However, as the clouds thin out through the remainder of the overnight hours, temps should fall back. Should still see readings bottom out in the teens inland and even reaching into E coastal areas, and from 20-25 along S coastal areas. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... Today... Departing H5 vort max with accompanying enhancement to the low- level wind profile. Mixing out to around H9 through the day, there`s the possibility of some breezy W winds during the morning, otherwise relaxing through the remainder of the day beneath a follow-up brief, weak ridge of high pressure. Boundary layer lapse rates remaining well mixed, beneath a dry inversion, and anticipating temperatures to warm into the mid and upper 30s, with snow melt, can`t rule out some few to scattered pancake cumulus. Tonight... Continued energy and moisture accelerating through the pseudo- zonal flow, sagging S into the Great Lakes region. Up against high pressure over the SE CONUS, an amplified gradient wind response with accompanying speed max at H925. Warmer, dry air pushing out of the SW, warming within H9-7 apparent within model forecast soundings, limitations on mixing down to the surface. Thus expecting a gradient wind response with strongest winds potentially in excess of 30 mph along the S-coast, across the Cape and Islands. Keep it dry but also mild with the winds. Lows down in the 20s for most locations. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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230 AM update... Highlights... * Dry and mild Sunday * Risk of some wintry mix/ice in the interior late Mon/Mon night * A period of heavy rain and strong coastal winds likely late Mon night into Tue * Blustery and seasonably cold Wed/Thu Sunday... Less wind Sunday with NW flow but continued mild with temps in the 40s across much of the region. Expect mostly sunny skies as axis of mid/high level moisture across northern New Eng. Turning colder Sun night as cold front drops south across the region with strong high pres building across Canada and ridging nosing down into New Eng. Monday into Tuesday... Developing warm advection pattern ahead of warm front will lead to some light precip developing Mon afternoon and more likely Mon night. With high pres to the N/NE and good cold air damming signature, thermal profiles should be cold enough for some light snow/mix/ice in the interior with minor accum possible. A brief mix is also possible at the onset in the coastal plain. However, the main event will likely be late Mon night and especially Tue as potent mid level trough/low lifts NE across the Gt Lakes. Ptype mostly rain but ECMWF has low level cold air lingering into Tue morning across interior MA where some wintry mix/ice may continue before precip quickly changes to rain. Models indicate a strong pre-frontal low level jet which will advect high PWAT airmass northward into New Eng. PWAT and low level wind anomalies around +2SD which suggest potential for heavy rainfall and gusty winds. As previous forecaster noted, some convection also possible given steep mid level lapse rates. However, system is progressive which should limit excessive rainfall potential. Still, deterministic GFS/ECMWF/GGEM all indicate potential for 1"+ QPF and EPS has moderate probs of 1 inch rainfall. Temps may reach into the 50s in the coastal plain with 40s elsewhere. Wednesday and Thursday... Blustery and colder weather expected but dry conditions with NW flow. GEFS and EPS mean 850 mb temps around -8C Wed and -10C Thu so near seasonable temps expected, perhaps a bit below normal Thu.
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&& .AVIATION /08Z FRIDAY THROUGH TUESDAY/...
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Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Saturday/...High confidence. Overnight...Mainly VFR. MVFR CIGS will likely hang close to E coastal MA, but impact the Cape and Islands with a more N/NE onshore flow. Expect winds to become more northerly towards daybreak Fri. BKN-OVC MVFR along the slopes of the Berkshires. Otherwise mostly clear skies. W-NW winds prevail. Friday... VFR. Brief period of breezy W winds as SCT-BKN high clouds erode. FEW-SCT around 3500 ft possible during at times around midday. Friday night... VFR. W winds on the increase towards Saturday morning. Mainly a gradient wind with the potential of sustained values up to 25 kts, gusts up to 30 kts. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Saturday Night through Tuesday/... Saturday Night: VFR. Breezy. Sunday through Sunday Night: VFR. Monday: Mainly VFR, with local MVFR/IFR possible. Chance RA, chance SN in the afternoon. Monday Night: Mainly MVFR, with areas IFR possible. Breezy. RA likely. Chance SN, FZRA, PL interior. Tuesday: Mainly MVFR, with local IFR possible. Windy with gusts to 30 kt. RA.
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&& .MARINE...
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Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Saturday/...High confidence. 1030 PM Update... Small Craft Advisories remain in effect over the open waters E and S of Cape Cod and the southern outer waters. Winds gusting to around 20 kt there with seas remaining around 5 ft. Seas will hold at around 5 ft through the night, then should subside briefly on Friday. Continued W winds through Friday. Greater concern is on the Friday night into Saturday morning period with increasing sustained winds potentially up to 25 kts, gusts up to 30 kts. Small Craft headlines may need to be renewed. There is also a low risk of low end Gales. Outlook /Saturday Night through Tuesday/... Saturday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Sunday through Monday: Winds less than 25 kt. Seas locally approaching 5 ft. Monday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Rain likely. Tuesday: Low risk for gale force winds with gusts up to 35 kt. Rough seas up to 12 ft. Rain.
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&& .HYDROLOGY... A Flood Warning remains in effect for the Connecticut River at Middle Haddam, where ice jams are causing river fluctuations. For details on specific area rivers, including observed and forecast river stages, please visit the Advanced Hydrologic Prediction Service (AHPS) graphs on our website. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory for hazardous seas until 6 AM EST early this morning for ANZ254>256. && $$ SYNOPSIS...KJC NEAR TERM...EVT SHORT TERM...Sipprell LONG TERM...KJC AVIATION...KJC/EVT/GAF MARINE...KJC/EVT/GAF HYDROLOGY...

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