Area Forecast Discussion
Issued by NWS Boston, MA

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855 FXUS61 KBOX 280321 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 1121 PM EDT Thu Oct 27 2016 .SYNOPSIS... Low pressure will push across the region overnight, with bands of heavy rain moving across. A few thunderstorms will move along south coastal areas as well as strong wind gusts across eastern and south coastal areas. Some mixing with light snow will end overnight as temperatures slowly rise above freezing across the higher inland terrain. Drying trend Friday but becoming breezy behind departing low pressure. A cold front may bring a few showers to the region Sat afternoon and evening. Low pressure may form on this front and bring the risk for a period of rain to the area Sunday. Dry much of next week with temperatures cool Monday but becoming mild Tue and Wed. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 11 PM Update... First band of heavier rainfall has pushed off of east coastal Mass at 03Z, but one more area of rainfall across S central Mass into Connecticut will shift E across central and eastern areas through 3-4 AM. Temperatures have hovered around freezing across N central and NW Mass through this evening, so light snow and sleet has been reported there. However, expect this to finally change over to rain as E-SE winds pick up and scour out the colder air. Noting a few thunderstorms that have developed S of Long Island at 03Z, but as better elevated instability with and ahead of dry slot behind the second area of rain moves in, will see a few more storms form mainly over the coastal waters. Still expect period of gusty SE-S winds that will mix down with any convection or heavier rainfall, so have continued the wind advisory across E and SE Mass into E RI. Have updated overnight forecast incorporate this evening`s conditions, as well as adjusted temps/dewpts/winds. Near term timing has also been adjusted to reflect current conditions. Previous discussion... Wind potential...Low level jet increases as it moves across Rhode Island and SE Massachusetts. This coupled with the rain and potential convection will result in strong, gusty winds mixing down to the surface. Wind advisory criteria is expected on the Cape and Islands. Think there is a decent chance that higher winds will mix down in the convection elsewhere along the E and S coasts of MA and RI. In addition, temperatures rising in the warm sector will allow for better mixing through the coastal plain. Kept the wind advisory as is for the overnight period. Temperatures...With the warm sector moving over portions of RI and SE MA overnight, expect temperatures to climb into the 50s if not near 60 on the south coast. Low temperatures will be in the mid 30s in western MA to the mid 40s in the coastal plain before we warm sector. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... Will see the rain coming to an end from west to east early Friday morning. Much of Friday should be dry with the shortwave and associated surface low moving out to the Gulf of Maine during the day. Attention will then be turned to the northwesterly winds as the surface low deepens just offshore. Expect near advisory criteria on the Cape and Islands at times during the day. Elsewhere along the coast it should be just below, in the 25 to 35 kt range. Further inland, gusts to 20 to 25 kts are expected. High temperatures will be reached early on in the day with the warmest temperatures on the coastal plain where the warm sector moved over during the overnight. Elsewhere, highs in the upper 40s to around 50 are expected. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Highlights... * Temperatures more seasonable during this period * Risk of a few showers late Saturday, a more widespread rain Sunday? * Mainly dry and seasonable much of next week This Weekend... Latest guidance continues to wrestle with the details. Southern New England is almost right in the middle between a high pressure to our south, and a low pressure to our north. Proximity to one over the other will be a huge factor in our ultimate weather. The tolerance is rather small, just a matter of 50 miles or so, between a dry forecast, or a significantly more wet one. At this time, it appears Saturday will be dry for most locations, with any showers in southern New England arriving very late in the day across western MA. This timing is subject to change. Showers expected to become more widespread Saturday night into Sunday, as a cold front pushes offshore Sunday afternoon and evening. Still not very certain this front will move well away from our region with a high pressure sitting off the Mid Atlantic coast. Again, relatively small distances can have a big impact on our weather in this scenario. As such, will keep a chance of showers across southeast MA and portions of RI for the first half of Sunday night. Temperatures look rather seasonable at this point. However, if we are closer to the colder air to our north, the current forecast may be too high. Monday through Thursday... Colder air briefly makes an appearance Monday as a high pressure moves through the Saint Lawrence River valley. Once this high pressure moves farther east, temperatures should become more seasonable, again. Mainly dry during this period, with a low risk of showers sometime Tuesday night into Wednesday. While a cold will be passing by during that time, there is not a lot of moisture with it. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday/... Overnight...High confidence in trends, lower on timing. Rain will continue through the night with periods of heavy rain possible. Expect a mix of MVFR-IFR conditions in rain/patchy fog. On the coastal plain, the south coasts of RI/MA, and the Cape and Islands; E-SE winds will gust up to 35 to 40 kts at times. Elsewhere, winds will be a bit lighter, gusting up to 25 kt along the east coast, and below 20 kt across the interior. Friday...High confidence in trends, lower on timing. Will see patches of rain coming to an end from SW-NE, with NE MA the last to dry out. Conditions will improve to MVFR and even VFR in some places. W-NW winds will remain gusty through the day, particularly on the Cape and Islands where gusts up to 40 kts are possible. KBOS TAF...High confidence in trends, lower confidence in timing. KBDL TAF...High confidence in trends, lower confidence in timing. Outlook /Friday Night through Tuesday/... Saturday-Sunday...Low confidence. VFR likely Saturday, with perhaps a period of marginal MVFR in scattered showers late Sat/Sat night. Possible MVFR-IFR Sunday across CT/RI and southeast in periods of rain. Monday-Tuesday...High confidence. VFR, with mainly dry weather. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday/...High confidence. Southeasterly gale force wind gusts are expected into Friday, eventually switching over to the northwest. Gale Warnings are up for all waters and may need to be extended farther into Friday evening/night. Waves increase to 8 to 10 feet on the outer waters. Periods of heavy rain and fog may limit visibilities at times tonight. Outlook /Friday Night through Tuesday/... Saturday-Sunday...Low confidence. Developing southwest winds 20-30 kt Sat ahead of approaching cold front. Wind shift Sunday morning to northwest behind this departing front. However, boundary should be slow to move too far away, with the possibility for a low pressure to develop along it over NJ. This low pressure could then track south of Long Island Sunday afternoon, and then across Georges Bank Sunday night. Monday-Tuesday...Moderate confidence. Modest north winds Monday behind the departing low pressure. Light winds Tuesday, as a high pressure crest over the area. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...Wind Advisory until 10 AM EDT Friday for MAZ007-014>024. RI...Wind Advisory until 5 AM EDT Friday for RIZ007-008. MARINE...Gale Warning until 6 PM EDT Friday for ANZ231>234-254-255. Gale Warning until 9 AM EDT Friday for ANZ230. Gale Warning until 5 AM EDT Friday for ANZ236. Gale Warning until 9 AM EDT Friday for ANZ235-237. Gale Warning until 6 PM EDT Friday for ANZ250-251. Gale Warning until 2 PM EDT Friday for ANZ256. && $$ SYNOPSIS...Belk/RLG NEAR TERM...Belk/EVT SHORT TERM...RLG LONG TERM...Belk AVIATION...Belk/RLG/EVT MARINE...Belk/RLG/EVT is the U.S. government's official web portal to all federal, state and local government web resources and services.