Point Forecast Updated 2:54 am EST Dec 11, 2018
Hi 34 °F
Sunny, with a high near 34. Light and variable wind.
Lo 20 °F
Partly cloudy, with a low around 20. Light and variable wind.
Hi 32 °F
Sunny, with a high near 32. Northwest wind 6 to 9 mph, with gusts as high as 22 mph.
Lo 10 °F
Mostly clear, with a low around 10. North wind 3 to 7 mph.
Hi 32 °F
Mostly sunny, with a high near 32. Light and variable wind becoming north around 5 mph.
Lo 23 °F
Partly cloudy, with a low around 23. Light south wind.
Hi 42 °F
Mostly sunny, with a high near 42. Calm wind becoming south around 5 mph in the afternoon.
Lo 35 °F
Rain likely, mainly after 1am. Mostly cloudy, with a low around 35. Southeast wind 3 to 5 mph. Chance of precipitation is 60%.
Hi 44 °F
Rain likely, mainly after 9am. Mostly cloudy, with a high near 44. Light and variable wind. Chance of precipitation is 60%.
000 FXUS61 KBOX 110301 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 1001 PM EST Mon Dec 10 2018 .SYNOPSIS... Mainly dry and cold weather prevails into Thursday, except for some scattered ocean effect snow showers possible late Tuesday night into Wednesday night mainly across the outer-Cape. Milder temperatures arrive Friday and continue into early next week with the best chance for rain Friday night into Saturday in association with low pressure. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... No major changes with this update. Brought the forecast back in line with observed trends, particularly temperatures. Ocean effect clouds continue to linger around the outer Cape and portions of Nantucket. Adjusted sky cover a bit using the latest high resolution guidance. Still expecting more clouds to work farther west across the Cape later tonight. 640 pm update... Previous forecast on track with a ridge of high pressure in control. Light winds/mainly clear skies will result in an ideal night of radiational cooling. Low temps by daybreak should be well down into the teens in many locales with perhaps even a few high single digit readings in the normally coldest outlying locations. The only exception to the mainly clear skies will be some ocean effect clouds mainly impacting the Cape/ACK at times overnight...but can not rule out a few across Cape Ann/Plymouth county. While they have temporarily dissipated...we may see them reform as flow just off the deck turns a bit more easterly albeit very light. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday... Dry conditions prevail during the day, with high pressure over our area. A clipper type system approaches our area from the west, moving thru the Great Lakes Region as the day progresses. This allows the flow to shift from N/NNE to W/SW over the course of the day. If some ocean stratocumulus redevelop, could have partly cloudy skies over mid and outer Cape/Nantucket to start. Then increasing sunshine expected as the winds turn to the W/SW. Otherwise another sunny/mostly sunny and cold day is forecast for southern New England. Highs will range from the upper 20s to mid 30s across the interior, to the 30s along the coastal plain. Tuesday night... The surface low pressure and associated northern stream short wave/mid level trough push eastward thru our area during Tue night. There is not much moisture with this feature as it moves thru our area, expecting mainly some clouds. Slight chance of snow showers during the overnight, mainly near/across the Cape and Islands as winds turn to the NNW, enabling an ocean effect component. Little or no accumulation is expected. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * Mainly dry/cold Wed into Thu but some ocean effect snow showers possible mainly across the outer-Cape Wed into Wed night * Milder weather arrives Friday into early next week, but some wet weather possible at times w/greatest risk Fri night into Sat Details... Wednesday and Wednesday night... Vigorous northern stream energy swings across the region early Wednesday. This upper level energy will be associated with a distant ocean storm...so will have to watch for an inverted trough. At this point...guidance indicates that the bulk of the moisture/instability and convergence remains offshore and is also rather progressive. While these things are difficult to forecast even in the very short term...odds favor this being too progressive/offshore for much impact. Therefore...most of the region probably remains dry except for mainly portions of the Cape, which will discuss in the next paragraph. It will be rather cold with highs on Wed mainly in the lower to middle 30s. Low temps Wed night should be well down into teens in most locations...but some high single digit readings are possible across the normally coldest outlying locations. With that said...there may be enough convergence and moisture with the inverted trough for a brief period of snow showers into part of Wednesday morning across the Cape and and perhaps even Nantucket/Plymouth county. Then later Wed into Wed night...strong cold air advection will allow 850T to drop to between -13C and -15C across far eastern New England. This will result in the SST differential around 20C and ocean induced capes near 400 J/KG. This modest instability and favorable northerly wind trajectories will probably bring a period of ocean effect snow showers to the outer-Cape Wed afternoon/night. Depending on exact wind direction may see this activity get briefly into Plymouth county and Nantucket. Snow accumulations of a coating to 1 inch are possible mainly across the outer-Cape with perhaps very localized 2 inch amounts. Thursday... Large high pressure will be centered over our region. Given the very cold start/limited mixing and low December sun angle it will be a rather cold day. Despite lots of sunshine...many locations will only see high temperatures in the lower to middle 30s. Friday through Monday... A significant pattern change will be occurring with an active Pacific jet taking control. The cold weather we have been dealing with the last month will be flushed out with the active Pacific jet. Given the pattern in transition...the models are going to struggle with northern and southern stream energy, timing and their interactions. The long range guidance and ensembles show quite the spread in solutions. We will say that the best chance for precipitation looks to be Friday night into Saturday...but additional chances will be possible into early next week. Ptype will strongly favor rain given milder Pacific air invading the region. && .AVIATION /03Z TUESDAY 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. Tonight and Tuesday... Mainly VFR. Exception is possible SCT-BKN VFR/MVFR cigs tonight into Tuesday across the mid to outer Cape/Nantucket. Low risk for some of these clouds to briefly impact Cape Ann/Plymouth county too. Light N/NNE winds tonight becoming light S/SW Tue. Tuesday night... VFR, except MVFR cigs possible Cape/Islands. Slight chance -SHSN, mainly Cape/Islands. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Wednesday through Saturday/... Wednesday: VFR. Breezy. Wednesday Night: Breezy. Thursday through Thursday Night: Friday: Breezy. Friday Night: Windy with local gusts to 30 kt. Chance RA. Saturday: Windy with gusts to 35 kt. Chance RA. && .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. Tonight... Winds slowly diminish but remain N-NE. Gusts up to 20 kt possible across the outer waters this evening. Seas around 2 to 4 feet away from the coast. Tuesday...High pressure moves across the waters as another weak low approaches from the W. light NE winds become variable to SW. Seas continue at 4 ft or less. Tuesday night...Weak low pressure moves across the waters. Light west winds becoming NW and increasing to 10 to 15 kts, gusts to 20 kts possible towards daybreak. Slight chance of snow showers. Outlook /Wednesday through Saturday/... Wednesday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Chance of snow showers. Wednesday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of snow showers. Thursday: Winds less than 25 kt. Seas locally approaching 5 ft. Thursday Night: Winds less than 25 kt. Friday: Winds less than 25 kt. Seas locally approaching 5 ft. Friday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Chance of rain. Saturday: Low risk for gale force winds with gusts up to 40 kt. Local rough seas. Chance of rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Frank/NMB NEAR TERM...Belk/Frank SHORT TERM...NMB LONG TERM...Frank AVIATION...Frank/NMB MARINE...Frank/NMB