DAYS 1-5 (APRIL 17-21)
This is one of our area’s “big days”. Patriots Day is always full of activity that can be impacted by weather, from battle re-enactments in Lexington/Concord to the Boston Marathon to the traditional morning first pitch Red Sox home game at Fenway. And while not directly weather-dependent, Boston will continue extra busy this evening, not only as the final runners from the marathon cross the finish line, but as the Boston Bruins begin their playoff run with a home game against the Florida Panthers. While we will have a low pressure system impacting our region today, it will work out pretty well overall. Lingering low level moisture put in place by an onshore flow associated with weak low pressure moving by the region yesterday means that we will start the day with areas of fog and drizzle under a low overcast, but without much wind. It’ll be cool and on the damp side, but not terrible for anybody outside for the aforementioned activities. Conditions for runners look pretty decent but not ideal as some mist/drizzle is around to start and some rain showers can pass through at any time during the race. These showers will be associated with a cold front, parented by low pressure passing well to our north. The front will move across the region from west southwest to east northeast during the afternoon and early evening, when showers are most likely, but the bulk of them occurring after most of the outdoor activities have ended (other than the later finishing marathon runners). Once the front moves by, drier air will sweep in around the broad circulation of the low on a west southwest wind into Tuesday, but as surface low pressure moves away through eastern Canada, we’ll still have a pool of chilly air aloft to cross the region, associated with upper level low pressure. This means that while Tuesday will likely dawn mostly sunny, we’ll see a fair amount of diurnal clouds popping up, and some of these may grow enough to produce a few showers. A gusty breeze will blow as well, although it won’t be too chilly with modified air arriving via the Midwest. We will cool down a few degrees for Wednesday with a little more northwesterly air flow to the east of a narrow area of high pressure in the Great Lakes. This high will slide across the region Wednesday evening then to the east by Thursday, opening the door for a warm front to move into the area with more cloudiness and eventually a light rain chance. We should be into the warm sector by Friday, but a cold front will approach later in the day with a shower chance resulting.
TODAY: Cloudy. Areas of drizzle/fog until mid morning. Isolated to scattered showers mid morning to midday, scattered to briefly numerous showers midday-afternoon. Highs 55-62. Wind E under 10 MPH early, SE up to 10 MPH thereafter until late-day, then SW 5-15 MPH with higher gusts by evening.
TONIGHT: Clearing. Lows 44-51. Wind SW 5-15 MPH.
TUESDAY: Sun to start, then lots of clouds and a possible passing shower. Highs 56-63. Wind SW 10-20 MPH.
TUESDAY NIGHT: Partly cloudy. Lows 36-43. Wind WSW 5-15 MPH.
WEDNESDAY: Mostly sunny to partly cloudy. Highs 53-60. Wind WNW 5-15 MPH, higher gusts.
WEDNESDAY NIGHT: Partly cloudy. Lows 38-45. Wind NW up to 10 MPH.
THURSDAY: Clouding up. Slight chance of light rain. Highs 58-65. Wind variable becoming S 5-15 MPH.
THURSDAY NIGHT: Mostly cloudy. Chance of a shower. Lows 50-57. Wind SW 5-15 MPH.
FRIDAY: Variably cloudy. Chance of showers late-day or evening. Highs 63-70 except cooler in coastal areas, especially South Coast. Wind SW 10-20 MPH.
DAYS 6-10 (APRIL 22-26)
A frontal system and additional low pressure in the region for the April 22-23 weekend means unsettled weather – may not rain at all times but will have to watch for shower chances and variable temperatures. Will work out details in the days ahead. Trending drier and cooler thereafter.
DAYS 11-15 (APRIL 27 – MAY 1)
Overall idea is near to below normal temperatures with some unsettled weather at times as a low pressure trough will be in control of the weather.