DAYS 1-5 (APRIL 17-21)
Happy Easter to those celebrating today! It’s a bright and beautiful but chilly and breezy Easter morning as I write this, and it’s going to be a cool and fairly blustery day, but we won’t keep the bright sunshine all day. As a pool of even colder air moves overhead, we’ll see a significant amount of diurnal cloud formation starting later this morning and through afternoon, some of them potentially releasing rain showers, some of which may contain rimed snowflakes a.k.a. graupel, and a few of the stronger showers can even contain small hail and produce lightning and thunder, so keep that in mind if you have outdoor plans. That settles down by evening and we lose the clouds after, setting up a clear and cold night as high pressure builds overhead. We start Monday out quite cold, with even some below-freezing low temperatures in the cold spots, and 30s for most of the area. With sunshine abundant in the morning, we’ll see a quick temperature rise, but it’s not going to be a warm day by any stretch with highest temps in the lower to middle 50s, even getting knocked back to below 50 along the shoreline due to a developing sea breeze. For the Boston Marathon, runners will gather in a significant morning chill, but at least we’ll have lost the wind from today by then. At the starting line it will be warming through the 40s and during the race into the 50s. As runners approach the finish line they will likely start feeling a sea breeze coming at them with a slight drop in temperature. This will especially be true for later-finishing runners. At Fenway park, it will be a dry but cool day for the midday baseball game. Hey, it could be worse, we’ve dealt with significant coastal storms for Patriots Day in the past, and this time, we’re going to miss by a handful of hours, as a coastal storm takes shape and brings a period of rain (and even some interior higher elevation snowfall) to the region Monday night and Tuesday morning. Right now I feel that the best chance of snow in the WHW forecast area is still southwestern NH and north central MA, mostly near and above 1000 feet in elevation, where some accumulation may occur. These situations are hard to forecast in the spring and we’ll just have to watch it closely. Either way, the system will begin to move away during the second half of Tuesday, and we dry out but with a lot of lingering clouds, chilly air, and a gusty wind. High pressure builds in with fair and cool but more tranquil weather Wednesday. A breeze returns Thursday but this time it will be a milder breeze ahead of an approaching cold front, which may bring some rain showers to the region as well.
TODAY: Sunny start, then lots of clouds. Isolated to scattered showers this afternoon which may contain graupel and/or hail, and a slight chance of lightning/thunder. Highs 48-55. Wind NW 10-20 MPH, higher gusts.
TONIGHT: Partly cloudy evening. Clearing overnight. Lows 28-33 except 34-39 immediate shoreline and urban centers. Diminishing NW wind.
MONDAY: Sunny morning. Increasing high clouds afternoon. Highs 51-58, turning cooler coast afternoon. Wind variable up to 10 MPH with coastal sea breezes.
MONDAY NIGHT: Thickening overcast with developing rain and the potential for mix/snow with some minor accumulation interior higher elevations. Lows 33-40. Wind NE 5-15 MPH, higher gusts.
TUESDAY: Overcast with rain likely morning. Breaking clouds afternoon. Highs 46-53. Wind NE to NW 10-20 MPH, higher gusts.
TUESDAY NIGHT: Variably cloudy evening, clearing overnight. Lows 36-43. Wind NW 10-20 MPH, higher gusts.
WEDNESDAY: Mostly sunny. Highs 55-62. Wind NW 5-15 MPH.
WEDNESDAY NIGHT: Mostly clear. Lows 45-52. Wind SW 5-15 MPH.
THURSDAY: Partly sunny. Chance of rain showers. Highs 60-67, cooler South Coast. Wind SW 10-20 MPH.
DAYS 6-10 (APRIL 22-26)
A westerly (zonal) flow pattern is expected to start this period and may begin to evolve into more of a blocking pattern before the end of it. Best opportunity for wet weather comes around April 24.
DAYS 11-15 (APRIL 27 – MAY 2)
Leaning still toward a blocking pattern with near to below normal temperatures and the potential for a longer period of unsettled weather.