Area Forecast Discussion
Issued by NWS Boston, MA

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588 FXUS61 KBOX 260015 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 815 PM EDT MON JUL 25 2016 .SYNOPSIS... A weak cool front may cause scattered showers and thunderstorms tonight...a few with gusty winds, especially in western and southern portions of the region. High pressure will bring dry but hot conditions Tuesday and Wednesday. A cold front approaches the area on Thursday. This front may linger in our area into this weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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800 PM update... Radar and IR satellite imagery indicating that thunderstorm prospects across southern New England are rapidly dwindling. As of 8 pm, the main area of convection extended from south of Long Island westward thru southern NJ into southeast PA. Still some thunder w/00Z obs in southwest CT. While we still can`t rule out scattered showers and isolated thunderstorms within the area this evening, the threat for strong thunderstorms within our county warning area has abated. Thus have removed enhanced wording from zones/grids. A cool front moves through southern New England late tonight. Skies are expected to clear out tonight for most of the area. Surface dew points will be slow to decrease even as winds shift toward the W-NW. Expect some localized ground fog especially where rainfall may have been observed. Indications suggest Cape/Islands see a mix of marine fog/stratus. Minimum temps mainly 65 to 70.
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&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday...Even with some cooling aloft, high temperatures still are forecast to soar to the low to mid 90s. This is courtesy of mostly sunny skies, some downsloping west-northwest flow, and 925 mb temperatures from 23C to 25C. Tuesday night...Dry with high pressure in control. Lows in the 60s to near 70 along coast. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * Lower humidity lingers thru midweek * Hot temperatures anticipated Wednesday away from the coast * Cold front approaches the region on Thursday * Showers and thunderstorms are possible again Friday and possibly into the weekend Overview... 25/12z guidance is in decent overall agreement through mid week.However there continues to be significant differences in solutions for Thursday night and on. 12Z models seem to be in general agreement on bringing a cold front into our area Thursday or Thursday night. However, models differ on when the front pushes south of our area. Will continue to go with a consensus approach for this forecast. Details... Wednesday and Wednesday night...Dry weather with high pressure in control. Still hot, especially away from the coasts. Sea breezes are expected to develop, which should help to limit high temps along the shorelines. Thursday...We should see another day of hot conditions, however a cold front will be approaching our area from the N/NW. Moisture increasing along the front should enable isolated to scattered afteroon t-storms on Thursday/Thursday evening. Thursday night and Friday...Uncertainty increases with this portion of the forecast. Models differ on how far south cold front pushes, as well as timing on potential open wave or deeper low pressure passing near/south of our area. Will have chance pops for showers/t- storms. Friday high temps expected to be a few degrees lower than previous days. Saturday and Sunday...Lots of uncertainty remains with this portion of the forecast, leading to a low confidence forecast. ECMWF keeps frontal boundary nearby, with potential low pressure moving along the front. GFS pushes the front south of our area for much of the weekend. Will continue with a chance of showers for this timeframe. Monday...Continued significant amount of uncertainty for this timeframe, could have a drier period with frontal boundary exiting the area. Will go with only slight chance pop for this period. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/...
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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 Tuesday Night/... 00Z Update: Through 03Z...Moderate confidence. Mainly VFR through the evening. Widely scattered showers this evening, with isolated thunderstorm with MVFR cigs/vsbys possible. IFR cigs/vsbys possible in marine stratus/fog Cape and Islands. After 03Z...Moderate confidence. VFR initially for most of the area, then late night MVFR fog especially at typically prone airports. IFR/LIFR stratus and fog anticipated along the Cape/Islands. Tuesday and Tuesday night...High confidence. Mainly VFR after early morning fog/stratus dissipates. Winds mainly NW with gusts 15-20 kt during the afternoon hours. KBOS TAF...Moderate confidence in TAF. VFR but chance of showers until about 02Z. KBDL TAF...Moderate confidence in TAF. Light rain showers in the area until 01-02Z, while thunderstorm activity to the south continues to diminish. VFR except localized MVFR visibilities in patchy fog late tonight. Outlook /Wednesday through Saturday/...Moderate to high confidence. High confidence Wednesday. Moderate confidence Thursday through Saturday. VFR conditions expected on Wednesday. Mainly VFR conditions Thursday, except MVFR cigs/vsbys possible in scattered afternoon/eveningshowers/thunderstorms. Thursday through Saturday...Mainly VFR, except MVFR cigs/vsbys possible in periodic showers and thunderstorms. Potential for patchy low ceilings/fog at night.
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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 Tuesday Night/...High confidence. Seas remain below SCA, although they may build to 3 to 4 ft along the south coast on Tuesday. Winds from the W-SW tonight will shift to mainly west to northwest on Tuesday with some gusts to 15-20 kt. Scattered showers and isolated thunderstorms are possible this evening, especially in the southern coastal waters. Light northwest winds Tuesday night. Outlook /Wednesday through Saturday/...Moderate to high confidence. Quiet boating weather is expected for Wednesday. During Thursday into Saturday winds and seas are expected to remain below SCA criteria, but the potential exists for areas of low clouds, fog, and scattered showers and thunderstorms which would limit visibilities at times.
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&& .FIRE WEATHER... During Tuesday, behind the departing cool front, much drier conditions are expected across southern New England. Minimum relative humidity during Tuesday is expected to range from 30 to 40 percent across much of the area. The exception is along Cape Ann and the Cape/Islands, where minimum RH values of 40 to 60 percent are forecast. Northwest winds around 10 mph may gust to 20 mph at times during Tuesday. Winds are expected to be lighter on Wednesday with nearshore sea breeze develompent. However, minimum RH will drop to 30 to around 40 percent across the interior. Along east coastal MA and southern RI, sea breezes will allow for higher minimum RH of 40 to 70 percent. && .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...Air Quality Alert until 10 PM EDT this evening for CTZ002-003. MA...Air Quality Alert until 11 PM EDT this evening for MAZ004>016- 026. RI...None. MARINE...None.
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&& $$ SYNOPSIS...NMB/GAF NEAR TERM...NMB/GAF SHORT TERM...GAF LONG TERM...NMB AVIATION...NMB/GAF MARINE...NMB/GAF FIRE WEATHER...Staff

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