This Afternoon: Hi 33 °F
Tonight: Lo 32 °F ↑
Dew Point: 17.2°F
Barometer: 30.40 in S
Snow Today: 0.0 in
Snow Saturday: 0.7 in
December: 15.8 in
Winter: 16.0 in
Depth: 8.0 in
Visibility: 10 miles
Avg: 2 mph
Gusts: 4 mph
National Weather Service Boston / Norton, MA
Point Forecast Updated Sun Dec 8, 2019 12:28pm EST
Hi 33 °F
Partly sunny, with a high near 33. South wind around 8 mph.
Mostly Cloudy then Slight Chance Rain Showers
Lo 32 °F ↑
A slight chance of rain showers after 5am. Mostly cloudy. Low around 32, with temperatures rising to around 39 overnight. South wind 7 to 10 mph. Chance of precipitation is 20%.
Rain Showers Likely
Hi 54 °F
A chance of rain showers before 8am, then rain showers likely and patchy fog. Cloudy, with a high near 54. South wind 5 to 14 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Lo 50 °F
Rain showers and patchy fog. Cloudy, with a low around 50. South wind 10 to 15 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Rain Showers Likely
Hi 57 °F
Rain showers likely and patchy fog. Cloudy, with a high near 57. Southwest wind around 10 mph, with gusts as high as 21 mph. Chance of precipitation is 60%.
Rain Showers Likely then Rain And Snow Showers Likely
Lo 31 °F
Rain showers likely before 2am, then rain and snow showers likely. Cloudy, with a low around 31. West wind 5 to 8 mph. Chance of precipitation is 70%. New snow accumulation of less than half an inch possible.
Chance Snow Showers
Hi 35 °F
A chance of snow showers before 4pm. Mostly cloudy, with a high near 35. West wind around 6 mph. Chance of precipitation is 40%. New snow accumulation of 1 to 3 inches possible.
Lo 21 °F
Partly cloudy, with a low around 21. West wind around 7 mph.
Hi 29 °F
Sunny, with a high near 29. Northwest wind around 7 mph.
Lo 17 °F
Mostly clear, with a low around 17. North wind around 5 mph.
Hi 34 °F
Partly sunny, with a high near 34. East wind 2 to 6 mph.
Slight Chance Snow Showers then Patchy Fog
Lo 28 °F
A slight chance of snow showers before 11pm, then patchy fog and a slight chance of snow showers between 11pm and 2am, then a chance of snow showers and patchy fog. Mostly cloudy, with a low around 28. East wind around 5 mph. Chance of precipitation is 30%.
Chance Snow Showers then Chance Rain Showers
Hi 44 °F
A chance of snow showers and patchy fog before 9am, then a chance of rain showers and patchy fog. Mostly cloudy, with a high near 44. Northeast wind around 6 mph. Chance of precipitation is 30%.
Chance Rain Showers
Lo 36 °F
A chance of rain showers and patchy fog. Cloudy, with a low around 36. North wind around 6 mph. Chance of precipitation is 30%.
000 FXUS61 KBOX 081813 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 113 PM EST Sun Dec 8 2019 .SYNOPSIS... Strong high pressure over southern New England this morning will shift off the coast during the afternoon, which will start a return flow of increasingly milder and more moist air. Scattered showers late tonight will turn into a soaking rain Monday into Tuesday. Strong southwest winds are expected in southeastern New England and all coastal waters late Monday afternoon and Monday night. A cold front moves through Tuesday night, and there might be some snow Tuesday night into Wednesday although confidence is very low at this point. Dry weather returns late Wednesday with colder temperatures for Thursday. Another coastal weather system may bring a mix of precipitation Friday or Saturday. && .NEAR TERM /UNTIL 5 PM THIS AFTERNOON/... 115 PM update ... Temperatures finally at or above freezing across most of MA/RI/CT, the only exception is the high terrain where temps are in the mid to upper 20s. Winds have shifting to the SSW, helping to modify the cold airmass over the region. Fortunately sunshine and SSW winds remaining light taking some of the edge off the unseasonably cold temps. Keep in mind normal high temps for 12/8 are 40-45. Previous forecast verifying nicely so no major changes with this update. Earlier discussion below. ================================================================= IR satellite shows some thin cirrus overhead, but generally clear skies. Thicker mid and upper clouds are found over far Western NY moving east. If these clouds hold together they may reach Western MA/CT around 2 PM, BOS-PVD 4-5 PM. Light winds become southerly this afternoon as the high pressure moves offshore. Overall a fair weather day. And although we have started rather chilly in some areas... subzero in parts of Western and Central MA... the sun and developing south wind will help temps recover into the 30s. Have adjusted hourly temps and dew points, but no significant changes to the forecast. && .SHORT TERM /5 PM THIS AFTERNOON THROUGH 6 PM MONDAY/... 340 AM update... Tonight...There is increasing southwestly flow aloft, with a 925 mb low level jet max of 50 knots noted from southeast NH to eastern ME late. Low level warm advection pattern will cause temperatures to slowly rise overnight. Low levels saturate toward daybreak Monday. Low cloudiness develops in CT and spreads northeastward overnight. SREF shows high probabilities of ceilings lower than 1000 ft. With increasing moisture in the low levels but still relatively dry air aloft most of the night, this spells more of a chance of some drizzle. Actual showers may develop by 3 or 4 AM. Temperatures in northwest MA could still be only in the mid 30s, so cannot rule out a few flakes of snow mixed in with any rain showers there, but it would be very short-lived. Temperatures should be in the 40s across RI and southeast MA by daybreak Monday. Monday... ** Rain and Wind ** Warm advection on strong south to southwest winds will lead to a rain, with embbeded heavier showers, across the entire region on Monday. Expecting 1 to 1.75 inches of rain before Monday night, when additional rain will occur (see below). A very strong low level jet will be working its way from the NJ coast to Long Island during the morning, reaching southern RI and the southeast MA coast very late in the afternoon. The NAM has been the strongest, with 80-90 kt at 2000 ft whereas other models are more like 60-70 kt. The big question is how much will mix down to the surface. This is tough because temperatures will soar to the mid and upper 50s in southeast MA and southern RI. That, combined with forecast lapse rates of 6C/km in the 925-700 mb layer, would make it likely that at least half would reach the surface. That would translate to wind gusts of 40-50 mph by 4 or 5 PM on Cape Cod and the Islands. Since the bulk of the winds would be Monday night, have held off on a Wind Advisory at this point, but either a Wind Advisory or High Wind Watches or Warnings may be issued later today. We have already issued Gale Warnings for all coastal waters...mariners take note. Coincident with the arrival of the aforementioned low level jet, an isolated rumble of thunder cannot be ruled out along the south coast toward evening. Even in northwest MA, temperatures will rise into the lower 50s, which will melt much of the remaining snow. Per discussions yesterday, there is 1 to 2 inches of water equivalent in the snowpack, which, when added to the falling rain, could lead to rises in river levels, but we are not expecting river flooding at this time. There will, however, likely be some urban and poor drainage flooding. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Big Picture... Broad upper trough digs over the Plains and Great Lakes Monday night and Tuesday while an upper ridge sits over the Western Atlantic. This creates a southwest flow aloft across the Eastern USA and brings milder air into Southern New England. The upper trough moves east midweek, crossing New England Thursday. Less agreement on the pattern for Friday-Saturday, but possibly a trough digs over the Plains, then sweeps east to New England over next weekend. Above normal 500-mb heights Tuesday fall below normal Thursday- Friday before increasing again on Saturday. So the deep layer is expected to be mild Tuesday, then falling below normal late week with signs of a recovery by Saturday. Mass fields and thermal fields in the models are similar through midweek but then show some model-to-model differences late in the week. This means moderate confidence through Tuesday, then diminishing to low confidence by Friday and Saturday. Daily Concerns... Monday night-Tuesday... Two features of note Monday night. One is a strong southerly low- level jet moving up the coast over Southern New England. This provides an inflow of moisture with PW values between 1 and 1.25 inches as well as low level forcing and lift. The second is a strong 150-kt upper jet moving east from the Plains and eventually curving up over Southern New England. The left exit region of this jet moves over us Monday evening and night, also generating lift. Temperatures will be above freezing through the lowest 10 thousand feet, so high confidence the precip type will be rain/showers. Low level south to southwest winds reach 60 kt within a couple of thousand feet of the surface, with highest values just offshore. Lapse rates will be near moist adiabatic in a shower-filled warm sector. Expect strong wind gusts to be brought to the surface, with gusts of 35 to 45 kt. Values similar to this are forecast at 1000 mb. Thus expect strong gusty winds Monday night and Tuesday. Guidance also suggests the precipitation comes in two segments: one Monday night followed by a break Tuesday morning and then a second segment of rain/showers late Tuesday and Tuesday night. Total rainfall during this time will be roughly 1 to 2 inches. Temperatures in the warm sector are indicated by 12C temps at 950 mb. If we have a lapse rate close to isothermal at night, expect nightime min temps in the lows to mid 50s. A similar temperature aloft with a dry adiabatic lapse to the surface would suggest max temps around 60 during the day Tuesday. Will show upper 50s and around 60 in the coastal plain, and mid 50s in Western/Central MA Tuesday night... Cold front sweeps through Southern New England Tuesday evening and early night. After it moves through, indications are that it turns parallel to the upper flow just as we move under the right entrance region of the upper jet. This should keep the front nearby overnight and maintain support for precipitation much of the night. With colder air moving in aloft, this may mean a changeover to snow with potential of a couple of inches. Cross sections show the deep column of moisture dries out by 12Z Wednesday, suggesting a diminishing chance of snow by sunrise. Wednesday-Thursday... Upper trough and associated cold pool move across New England on Wednesday. This should push any lingering precipitation offshore. Cold pool instability may generate some clouds and scattered rain/snow showers during Wednesday, with best potential in Western and Central MA and areas north of the MA border. High pressure then builds in with cold and dry weather Thursday. Friday-Saturday... GFS shows another coastal system moving up from the south Friday, spreading precipitation into Southern New England with continues into Saturday. The ECMWF is slower with the coastal system, moving precipitation ashore on Saturday. GFS temperatures are borderline, with potential for both rain and snow. The ECMWF temperature show predominently rain. Expect a mix of precipitation on one or both of the days, but with low confidence. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Monday/...High confidence. 1815z ... Thru Midnight ... VFR, dry weather and increasing SSW winds. After midnight ... VFR lowering to MVFR in scattered showers toward morning. Monday ... MVFR with embedded IFR especially inland. Periods of rain, moderate to heavy at times. LLWS 020/19045kt. Surface south at 20-25 kt, lighter winds elsewhere. Areas of fog will restrict vsbys in the MVFR/IFR category. Monday night ... A mix of MVFR/IFR in periods of rain, moderate to heavy at times. Areas of fog too. Rain possibly tapering off after 06z. LLWS 020/19050kt KBOS Terminal...High confidence in TAF trends, lower confidence on exact timing details. KBDL Terminal...High confidence in TAF trends, lower confidence on exact timing details. Outlook /Tuesday through Thursday/... Tuesday: Mainly MVFR, with areas VFR possible. Windy with gusts up to 30 kt. SHRA likely. Tuesday Night: MVFR/IFR conditions possible. Windy with local gusts up to 30 kt. SHRA likely, chance SHSN. Wednesday: Mainly VFR, with areas IFR possible. Breezy. Chance SHSN. Wednesday Night through Thursday: VFR. Windy with local gusts up to 30 kt. && .MARINE... Short Term /through Monday/...High confidence. 340 AM update: ** Gale Warnings now in effect for all coastal waters ** Today...Strong high pressure over southern New England moves offshore this afternoon. This shifts winds to a SSW direction. Dry weather and good vsby continue. Tonight...A low level jet over mainly northern New England will cause increasing wind gusts over the outer waters off Cape Ann and over Massachusetts Bay tonight. Winds there could gust over 30 kt. Seas will build to around 6 ft in those waters. Scattered showers developing late, mainly in the southern waters. Monday...Rough conditions. SW gales expected, with gusts of 35-45 kt all waters...but highest over the southeastern outer waters by late in the afternoon. Will need to watch for potential upgrades to Storm conditions. Widespread rain showers and the potential for an isolated thunderstorm toward evening over the southern coastal waters. Areas of fog. Visibilities reduced to 1 to 3 nm. Outlook /Monday Night through Thursday/... Monday Night: Moderate risk for gale force winds with areas of gusts up to 45 kt. Rough seas up to 15 ft. Rain showers likely. Local visibility 1 to 3 nm. Tuesday: Low risk for gale force winds with gusts up to 35 kt. Rough seas up to 14 ft. Rain showers likely. Tuesday Night: Moderate risk for Small Craft Advisory winds with local gusts up to 30 kt. Areas of rough seas. Rain showers likely. Wednesday: Winds less than 25 kt. Local rough seas. Chance of rain showers. Local visibility 1 to 3 nm. Wednesday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Seas up to 5 ft. Local visibility 1 to 3 nm. Thursday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Local rough seas. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Gale Warning from 1 PM Monday to 6 AM EST Tuesday for ANZ231>235-237-250-251-254>256. Gale Warning from 4 PM Monday to 6 AM EST Tuesday for ANZ230- 236. && $$ SYNOPSIS...WTB/GAF NEAR TERM...WTB/Nocera SHORT TERM...GAF LONG TERM...WTB AVIATION...WTB/Nocera MARINE...WTB/GAF
Note: Rain measured automatically by weather station. Rain totals do not necessarily include melted frozen precipitation.
For more accurate, manually measured rain data, see the Local Precip Data page.
4 snow days in December
7 snow days this season
Low wind chill today:
Low wind chill Saturday:
High dew pt today:
High dew pt Saturday:
Wind gust today:
Wind gust Saturday:
09 hours 11 minutes
Waxing Gibbous (88%)