Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 302320 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 720 PM EDT THU JUN 30 2016 .SYNOPSIS... A cold front will move across the region Friday night into early Saturday, and will be preceded by a round or two of scattered showers and thunderstorms Friday afternoon and evening. High pressure builds in behind the front and prevails through the middle of next week. && .NEAR TERM /THROUGH FRIDAY/...
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No major changes to the forecast this evening. Minor tweaks to reflect observed trends. High pressure will be offshore with light southwest flow. Dry weather will prevail with a few clouds. Patchy late night fog may develop in the CT valley. Lows will be in the upper 50s to lower 60s, except mid/upper 60s in Boston.
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&& .SHORT TERM /FRIDAY NIGHT/... ***A few strong to severe thunderstorms possible late Friday into Friday night with localized heavy rainfall*** Mid level trof and shortwave move east from the Gt Lakes with increasing moisture moving into the region, especially in the afternoon. As a result morning sunshine will give way to increasing afternoon clouds. Highs will reach the lower 80s away from the south coast and it will become increasingly humid as dewpoints climb into the 60s. We expect sct showers and t-storms to develop in the afternoon, especially west as mid level trof approaches from the west and atmosphere destabilizes with CAPES 500-1000 J/kg. The main concern for late Fri into Fri evening is the potential for strong to severe t-storms developing in western New Eng as 0-6km shear rapidly increases with values increasing over 40 kt aft 00z. Instability will likely be a limiting factor as much of the guidance keeps the better instability west of New England and instability will be weakening in the evening as deep layer shear increases. However, height falls in the evening and increasing mid level lapse rates with the trof should help to sustain convection as it moves in from the west ahead of the approaching cold front. We are confident in sct showers/t-storms moving across the region late Fri into Fri night, but lower confidence on severe threat which will be greater to the west where shear/instability line up. If instability can hold together into the evening, there is a small window for a few strong to severe storms to develop, mainly western New Eng late Fri/Fri evening. Strong winds and heavy rainfall will be the primary threat with t-storms. && .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGHLIGHTS... * Near to slightly above normal temperatures expected * High pressure brings dry weather for much of next week Overview...Quiet pattern continues through next week, starting with upper level ridging in the center of the country and upper troughs in the Pacific NW and the NE. The upper level pattern flattens out a bit by Monday, with weak ridging continuing across the middle of the country. Models remain in good overall agreement, and will continue to favor a consensus approach. High pressure builds into the region for the remainder of this holiday weekend. Low pressure passes south of southern New England Tuesday and Wednesday, but quiet weather should continue for our region. Temperatures...Aside from slightly cooler temperatures Saturday, behind a cold front, temperatures will gradually warm into next week. By the middle of next week, temperatures will be in the upper 80s to lower 90s, especially away from the coasts. Max temperatures should remain in the 70s across the Cape and islands. Precipitation...Looking at a dry forecast through the middle of next week. Slightly greater risk for showers Wednesday into Thursday as southern New England gets squeezed between two frontal boundaries. The main limitation will be relatively dry air in place. Kept the forecast dry, for now. && .AVIATION /23Z THURSDAY THROUGH TUESDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday Night/... Through Tonight...High confidence. VFR. Some localized patchy fog may develop late in the typically prone locations. Friday...Moderate confidence. Mainly VFR cigs. Scattered showers and t-storms developing in the afternoon, especially late in the day in western New England with brief lower conditions. Friday night...Moderate confidence. Areas of MVFR/IFR cigs possibly developing, especially east along with patchy fog. Showers and scattered t-storms likely moving across the region during the evening. KBOS Terminal...High confidence. KBDL Terminal...High confidence. Outlook /Saturday through Tuesday/... Saturday...High confidence. Any lingering MVFR conditions will improve to VFR by early morning. Sunday through Tuesday...High confidence. VFR. Low probability of seabreezes developing each afternoon. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday Night/...High confidence. Winds and seas should remain below small craft advisory thresholds through the period, but do expect southerly wind gusts around 20 knots Friday afternoon over nearshore waters. A few showers and t-storms may affect the waters Friday evening. Outlook /Saturday through Tuesday/... High confidence. Mainly quiet boating weather expected. Winds and seas remain below SCA criteria throughout the period. && .FIRE WEATHER... Hit or miss showers and thunderstorms are possible Friday and Friday night. However, widespread precipitation looks to be nil over the next 7 days. High pressure and dry conditions appear to take hold of the region Saturday, lasting through the middle of next week. Specifics are still too hard to nail down, but it looks like the area will be less humid and a bit cooler but dry during this time frame. RH values could drop close to 30 percent between Sunday into Monday. Winds overall appear to be light during this period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Belk/KJC NEAR TERM...Belk/KJC SHORT TERM...KJC LONG TERM...Belk AVIATION...Belk/KJC MARINE...Belk/KJC FIRE WEATHER...Belk/KJC is the U.S. government's official web portal to all federal, state and local government web resources and services.