Area Forecast Discussion
Issued by NWS Boston, MA

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153 FXUS61 KBOX 191829 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 129 PM EST Mon Feb 19 2018 .SYNOPSIS... A warm front will bring showers late today and tonight. This will set the stage for near record high temperatures Tuesday, and especially Wednesday, so long as enough sunshine is realized. Lower temperatures work into the region Thursday into this weekend, but still expecting them to remain above normal. Greatest risk for unsettled weather will be sometime Friday into next weekend. && .NEAR TERM /THROUGH TONIGHT/... Increasing clouds the rest of this afternoon. Persistent south winds led to some stratocumulus clouds across portions of RI and southeast MA. These clouds pretty much developed in place, but will likely persist until the clouds moving in from the west arrive. Temperatures should rise much more slowly the rest of today. Regional radar showing an area of showers moving across eastern NY state. These showers should first cross the Berkshires about 2 PM, reaching the Worcester hills between 3-5 PM, and Greater Boston between 5-7 PM. This is not a solid area of rain, so coverage is still expected to be hit-and-miss to some extent until later this evening. Risk for showers should gradually diminish after midnight. A warm front should move north of our region overnight. The persistent south winds should mean nearly steady to slowly rising temperatures through the night, too. Patchy fog is expected, which could become locally dense toward the south coast with the flow right off the ocean. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... Tuesday... A few showers and patchy fog may linger along south coastal areas early, then should push offshore by around midday. However, clouds will likely linger across most areas through the day. The big question will be whether the clouds will dissipate during the midday and afternoon hours across the interior. If the clouds do break more than currently forecast, max temperatures will likely be higher than current forecast, too. Tuesday night... Anomalous southwest flow will continue across southern New England. Low temperatures expected to be about 10 degrees above the normal high temperature for this time of year. Still thinking some low clouds and fog are possible, especially near the Cape/Islands with high dewpoint air moving over the relatively cool ocean. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Highlights... * Wednesday: Near all time February record highs might be approached if enough sunshine is realized * Cooler Thu/Fri into next weekend but temps still above normal * Unsettled weather possible sometime Friday into next weekend with ptype favoring rain although a bit of ice/snow can not be ruled out Details... Wednesday... Anomalous upper level ridge of 594 decameters off the southeast coast will pump an incredibly mild airmass into our region for late February standards. This will result in 850T rising to between +12C and +14C. Given southwest flow...high temperatures will climb well into the 60s to lower 70s inland from the cooling marine influence of the southeast New England coast. If this ends up being the case...record highs would be broken and near all time February record high temperatures would be challenged. The one fly in the ointment is if we are jammed up in a bunch of low clouds. NAM soundings suggests this as a possibility...but often southwest flow is able to allow for these to break up. However...if the low clouds remain in place high temps would be cooler than currently forecast. Something later shifts will have to monitor closely. Wednesday night and Thursday... While the southeast upper level ridge will remain in place, 1040+ MB surface high pressure system will approach from the west and force a cold front south of the region Wed night/Thu. The result will be significantly cooler temperatures Thursday with high temperatures mainly in the 40s. At this time...the bulk of the period looks dry but we can not rule out a period of mainly ana frontal showers which are depicted in some of the GEFS/EPS ensemble members. Friday through Sunday.... Low confidence forecast particularly with timing, but the potential exists for a couple rounds of unsettled weather Friday into next weekend. Certainly not expecting the entire period to be a washout...just impossible to try to time individual shortwaves this far out. The southeast ridge remains pretty strong...so ptype favors mainly rain. However...if a couple Canadian high pressure systems are slower to retreat it could be marginally cold enough to support a bit of snow/ice. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence in trends. Moderate confidence in timing. Through 00Z...Mainly VFR. Some MVFR cigs/vsbys should develop from west to east in scattered showers after 19Z. Tonight...Areas of MVFR CIGS/VSBYS in scattered -SHRA and patchy fog. Local IFR possible toward the south coast, including the Cape and islands. S winds gust up to 20 kt across Cape Cod and the islands. Tuesday...Mix of conditions. MVFR VSBYS/MVFR-IFR CIGS in scattered -SHRA and patchy fog early, improving to VFR. However, MVFR to local IFR conditions may linger along the S coast through early afternoon. Tuesday Night...Areas MVFR/IFR conditions should redevelop in low clouds and patchy fog. Breezy. Slight chance SHRA toward the S coast. KBOS Terminal...Moderate confidence in TAF. KBDL Terminal...Moderate confidence in TAF. Outlook /Wednesday through Friday/...Moderate confidence. Wednesday: Mainly VFR, with local IFR possible. Breezy. Slight chance SHRA. Wednesday Night through Thursday: Mainly VFR, with areas MVFR possible. Breezy. Chance SHRA. Thursday Night: VFR. Breezy. Friday: Mainly VFR, with areas MVFR possible. Breezy. Chance RA, slight chance FZRA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/...High confidence. Wind gusts not quite reaching 25 kt early this afternoon. So will give some thought to canceling some of the Small Craft Advisories early. Need to evaluate the sea state over the next hour or so, first. Rough seas still expected to develop across the ocean-exposed waters with the arrival of southerly swells. Will need to continue the Small Craft Advisories across those waters. Scattered showers and patchy fog will bring reduced visibility tonight, then should improve on the eastern waters Tuesday. Reduced visibility lingers Tuesday into Tuesday night on the southern waters in patchy fog and isolated showers. Outlook /Wednesday through Friday/...Moderate to High Wednesday: Winds less than 25 kt. Areas of rough seas. Slight chance of rain showers, patchy fog. Local visibility 1 to 3 nm. Wednesday Night: Winds less than 25 kt. Local rough seas. Chance of rain showers. Thursday: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers. Thursday Night: Winds less than 25 kt. Friday: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain. && .CLIMATE... Record Highest Observed Temperature for February...(since records began) Boston.........73 (2/24/2017) Hartford.......73 (2/24/1985) Providence.....72 (2/24/1985) Worcester......69 (2/24/2017) Record High Temperatures... February.......2/20......2/21 Boston.........68 (1930) 63 (1906) Hartford.......69 (1930) 63 (1930) Providence.....69 (1930) 63 (1930) Worcester......65 (1930) 59 (1930) Record Warmest Min Temperature... February.......2/20......2/21 Boston.........46 (1930) 45 (1994) Hartford.......50 (1981) 49 (1981) Providence.....48 (1981) 50 (1981) Worcester......47 (1981) 43 (2002) && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 5 PM EST this afternoon for ANZ230>234-236-251. Small Craft Advisory until 5 PM EST Tuesday for ANZ235-237-250- 254. Small Craft Advisory from 5 PM this afternoon to 5 PM EST Tuesday for ANZ255-256. && $$ SYNOPSIS...Belk/Frank NEAR TERM...Belk SHORT TERM...Belk LONG TERM...Frank AVIATION...Belk/Frank MARINE...Belk/Frank CLIMATE...Staff

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