Point Forecast Updated 7:26 pm EDT May 21, 2018
Lo 49 °F
Mostly clear, with a low around 49. West wind around 6 mph becoming calm in the evening.
Mostly Cloudy then Showers Likely
Hi 69 °F
Showers likely, mainly after 5pm. Increasing clouds, with a high near 69. Calm wind becoming south 5 to 9 mph in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Showers Likely then Chance Showers and Patchy Fog
Lo 53 °F
Showers likely, mainly before 10pm. Patchy fog after midnight. Otherwise, cloudy, with a low around 53. South wind 3 to 6 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Hi 77 °F
Cloudy, then gradually becoming mostly sunny, with a high near 77. Northwest wind around 6 mph.
Lo 51 °F
Partly cloudy, with a low around 51. West wind 6 to 8 mph becoming northeast after midnight.
Hi 68 °F
Mostly sunny, with a high near 68.
Lo 55 °F
Mostly clear, with a low around 55.
Hi 83 °F
Sunny, with a high near 83.
Lo 64 °F
Partly cloudy, with a low around 64.
112 FXUS61 KBOX 212320 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 720 PM EDT Mon May 21 2018 .SYNOPSIS... Dry and tranquil weather continues tonight. Rather cloudy skies are anticipated Tuesday along with cooler temperatures. A warm front will bring some showers to the region...generally Tuesday afternoon and evening. Mainly dry weather Wednesday through Saturday. Moisture increases through the weekend with the best chance of showers on Sunday. Much warmer Friday into the weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 7PM update... Overall, forecast remains on track. Both cloud cover and rain activity is going to be very slow as the column is quite dry even at this time. With light flow developing early, some radiational cooling should allow temps to fall into the low 50s before the cloud shield prevents further outgoing radiation. Lowered mins a bit. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Tuesday and Tuesday night... A rather cloudy day is on tap for Tuesday ahead of a warm front. There appears to be enough forcing/moisture along with a modest low level jet for some showers Tuesday afternoon/evening. Not expecting a complete washout...but most locations should see a period of wet weather during this time. There is even a low risk for a rumble or two of thunder...mainly near the south coast with some marginal elevated instability. High temperatures will be held in the upper 60s to around 70 in most locations given the clouds along with the afternoon/evening showers. The bulk of the showers should come to an end Tuesday evening...but a few will remain possible after midnight as a weak cold front crosses the region. Clouds will probably hang tough for most of the night and may see some fog develop given ample low level moisture. This should hold overnight low temperatures in the lower to middle 50s. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * A spot shower lingers Wednesday * Cool Thursday but much warmer into the weekend * Risk of showers increases by Sunday Overview... Through the mid term, the N stream dominates, mainly in the form of a longwave trof settling across the Maritimes which is linked to a Baffin Sea vortex. However, with the mean trof axis to the W, central CONUS ridging will lead to rising heights and generally cyclonic flow through the latter half of the week. It is not until the tropical disturbance in the Gulf of Mexico gets caught up with shortwave energy moving out of the Pacific that there is a transition for New England. These impacts, particularly with a plume of tropical moisture, could yield a wet latter half of Memorial Day weekend. Overall, enough agreement between guidance to use a consensus blend for this forecast update. Wed... Cold front slows as it begins to parallel mid lvl flow. However, soundings support rapid influx of drier air through the column, reducing PWATs to below 1.00in by mid day. Although this does steepen lapse rates, the overall lack of moisture may limit convective potential. Near NIL QPF supports this thinking. Still enough to warrant at least slight chance POPs. Delayed cold advection suggests highs should reach the mid 70s to around 80, especially as some clearing is observed. Thu through Sat... Mainly dry thanks to implied ridging through mid and upper lvl height rises and sfc high pres as a response. Thu looks to be the coolest day, but with H85 temps avg around +8C, it still should yield low 70s across much of the region. Milder Fri and Sat with temps in the upper 70s and low 80s thanks to a gradual increase in mid lvl temps. These are best observed inland however, as weak pres gradient suggests local sea breezes at area coastlines. Sun into early next week... Echo previous forecasters concern and lack of overall confidence as guidance widely diverges during this period. This is not surprising, as models often struggle with complex tropical interactions. At odds for New England, is a resurgence in N stream forcing trof out of the Arctic with its sfc response, a N-S moving cold front front which makes temperatures rather uncertain. From the S stream, is tropical moisture plume with PWATs potentially reaching near 2.00 inches just to the S. If this dominates a period of wet and very unsettled conditions are possible, keeping the front to the N. For now, will lean most heavily on ensemble means for this period as it takes into account the potential solutions. This will come into focus better as the feature players, particularly the tropical wave become better sampled. && .AVIATION /00Z 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/... Tonight...High confidence. VFR. Winds becoming light and variable. Tuesday and Tuesday night...Moderate to high confidence. Mainly VFR conditions into Tuesday afternoon. It probably will take until evening especially along the coast for MVFR to localized IFR ceilings and visibilities to arrive. These lower cigs/vsbys will likely persist Tuesday night. Some showers expected especially Tuesday afternoon and evening. A low risk for a rumble or two of thunder mainly near the south coast Tue evening. KBOS Terminal...High confidence in TAF. Still uncertainty though in wind direction through 22z. BOS sea breeze kicked offshore as of 19z...but still close enough where it needs to be watched for another few hours. KBDL Terminal...High confidence in TAF. Outlook /Wednesday through Saturday/...Moderate confidence. Wednesday: Mainly VFR. Wednesday Night: VFR. Breezy. Thursday through Thursday Night: VFR. Friday through Friday Night: VFR. Breezy. Saturday: Mainly VFR, with areas MVFR possible. Chance SHRA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/... Tonight through Tuesday night...High confidence. Weak pressure gradient will keep winds and seas below small craft advisory thresholds through Tuesday night. Biggest concern for mariners will be the potential for some fog developing Tuesday night along with the low risk for a rumble or two of thunder across our southern waters. Outlook /Wednesday through Saturday/...Moderate confidence. Wednesday: Winds less than 25 kt. Slight chance of rain showers, patchy fog. Local visibility 1 to 3 nm. Wednesday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Patchy fog. Local visibility 1 to 3 nm. Thursday through Thursday Night: Winds less than 25 kt. Friday: Winds less than 25 kt. Local rough seas. Friday Night: Winds less than 25 kt. Areas of rough seas. Saturday: Winds less than 25 kt. Areas of rough seas. Chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Frank/Doody NEAR TERM...Frank/Doody SHORT TERM...Frank LONG TERM...Doody AVIATION...Frank/Doody MARINE...Frank/Doody
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.
Rain Rate (/hr):
Rain Last 60 min:
High dew pt today:
High dew pt yesterday:
Wind gust today:
Wind gust yesterday:
14 hours 50 minutes
First Quarter (48%)