Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 170318 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 1018 PM EST Thu Feb 16 2017 .SYNOPSIS... Transition day for Friday as dry weather prevails and temperatures begin to moderate. A couple of moisture-starved cold front move through during the weekend and again the middle of next week. This will mean dry weather through the period. Mild weather over the weekend and mid week, with a cold snap early next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 10 pm update... Scattered cloud decks in association with continued potent impulse energy rotating through the deeper cyclonic low pattern centered over the Southeast Canadian Maritimes. Subsequent stacking of low pressure exerting its influence across the region via a tight pressure gradient coupled with continued height rises. Cold air advection with the low levels, the resultant momentum, somewhat enhanced locally per aforementioned potent impulses, should mix down especially over the high terrain and across the waters, thus continued blustery northwest winds when coupled with temperatures bottoming out to lows in the teens by morning will result in wind chills well down into the single digits. However, going to have to watch the interior valleys closely. Winds already light, a sign of decoupling, that with clear conditions, radiational cooling should proceed. None of the guidance capturing this well. Going to need a fine-eye to detail. Watching locations especially in and around the Worcester Hills (i.e., Orange MA). && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Friday and Friday night... Transition day across the region as mid-level ridge begins to build across the eastern Great Lakes. New England will see building heights and warming temperatures in response to the building heights. Anticipate gusty winds to continue tomorrow as thermal gradient increases the 925mb LLJ to 20-30 kts. Aside from the winds, expect a quiet day with temperatures in the upper 30s to low 40s. Mid-level ridge will then move into New England during the overnight hours. This will flip the NW winds to a more westerly to southerly direction as 850mb temps warm to near 0C. Overnight temperatures will still be below freezing but temps will be in the 20s to upper teens across the region. Quiet weather is anticipate, but may need to watch for a shower or two out west as mid-level moisture increases. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Big Picture... Northern and Southern streams in place for most of the long term period, with Southern New England under the Northern stream. Having the southern stream well to our south will hold much of the moisture over the southern states while just limited amounts of moisture move across our area. Best chance for these clouds would be over the weekend...especially Saturday night and next Wednesday. Model mass fields are similar through Tuesday, adding to confidence in the forecast through that time. Large scale features are similar after that, while shortwave features show differences Wednesday and Thursday. Forecast height contours are above normal for much of the period, and arguably well above normal mid week next week. This suggests above normal temperatures. Details... Overall, a quiet period for weather. Saturday through Monday... One shortwave starting over WA and OR races across the USA/Canada border region and crosses New England late Saturday/Saturday night. Surface low driven by this shortwave passes north of New England Saturday night, then swings a cold front south across the region Sunday night. Limited moisture with this system with most of the lift out of phase with the moisture. Warmer temperatures move in on westerly winds for Sunday. A second shortwave swings south from Hudsons Bay across our area and helps drive the cold front through. Moisture builds ahead of this shortwave, but is below 850 mb. Winds shift out of the north, bringing colder temps for Monday. Tuesday through Thursday... High pressure builds over the region Tuesday, then lifts northeast Wednesday. Another shortwave moves through either Wednesday or Thursday driving another cold front through the region. This one also looks moisture-starved and would mean at most some clouds. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Range /through Friday night/...High confidence. Tonight... VFR. W/NW winds blustery. Gusts 20-25 kts. SCT-BKN mid to high level cigs with perhaps some MVFR sneaking atop the N/W high terrain of MA. Friday into Friday night... VFR. Gusty N/W winds 20-25 kts. Dissipating towards evening and becoming light overnight. KBOS TAF...VFR. WNW winds gusting to 25 knots. High confidence. KBDL TAF...VFR. Diminishing wind. High confidence. Outlook /Saturday through Tuesday/... Moderate confidence. Saturday-Sunday... Mostly VFR. Warmer air moves in Saturday night and Sunday, and may support areas of IFR in fog in the CT River Valley and South Coast. Monday-Tuesday... VFR through the period. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Range /through Friday night/... High confidence. NW winds remain gusty overnight and into Friday with gusts 20-30 knots, remaining below gale force. Seas remained heightened. Low risk of freezing spray. As high pressure begins to approach from the west anticipate diminishing winds by Friday night. Outlook /Saturday through Tuesday/... Saturday-Sunday... Southwest winds gust near 25 knots. A Small Craft Advisory may be needed. West winds Saturday night turn from Northwest Sunday. There is a low chance for winds reaching 35 knots Saturday night and Sunday which would mean a WNW gale. Most seas should remain below 5 feet, although parts of the outer waters may approach 5 feet. Monday... North winds may gust 25-30 knots. Seas will be less than 5 feet except east of Cape Cod where seas may approach 5 feet. A Small Craft Advisory may be needed. Tuesday... Winds less than 25 knots and seas less than 5 feet. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 1 PM EST Friday for ANZ230>235-237- 251. Small Craft Advisory until 2 AM EST Friday for ANZ236. Small Craft Advisory until 1 AM EST Saturday for ANZ250- 254>256. && $$ SYNOPSIS...WTB/Dunten NEAR TERM...WTB/Dunten/Sipprell SHORT TERM...Dunten LONG TERM...WTB AVIATION...WTB/Dunten/Sipprell MARINE...WTB/Dunten/Sipprell is the U.S. government's official web portal to all federal, state and local government web resources and services.