DAYS 1-5 (MAY 20-24)
One more “summer preview” day today with very warm to hot air and moderate to high humidity in place until its pushed out by a cold front passing through the region. As this front moves through today, the atmosphere above is not as supportive for thunderstorms as it was yesterday, and the trigger point is further south, so I’m expecting the greatest chance for scattered activity to be from the I-90 belt southward this afternoon and evening, favoring the South Coast region the later it gets. It doesn’t mean we can’t see an isolated shower or storm to the north, but the chances are definitely lower up that way. The front will settle just to our south tonight into Thursday, and as a weak low pressure wave rides along it, a cloud canopy will remain in place, limiting Thursday’s sunshine quite a bit. In fact, some additional showers can move across the South Coast region, particularly during the morning hours. We may set up for a colorful sunset however, depending on the location of the edge of the cloud deck at the time the sun goes down. High pressure builds in with fair and seasonable weather for Friday. Will it hold into the weekend? The answer is: no. The high gives way to a slow return of the frontal boundary from the south, which allows clouds to increase on Saturday as low pressure gets set to track to our south. This process will be slow enough that despite losing the sunshine I do think we get through most of that day dry before rain arrives in the evening or at night from southwest to northeast, and continues during Sunday. Additional details about the full Memorial Day Weekend forecast will appear on tomorrow’s blog update.
TODAY: Variably cloudy. Shower and thunderstorm potential from late morning through afternoon, with highest thunderstorm potential I-90 belt southward. Highs 69-76 Cape Cod / Islands, 77-84 southeastern CT and southern RI to MA South Shore, 85-92 elsewhere. Wind SW increasing to 10-20 MPH, higher gusts possible, especially near any storms.
TONIGHT: Mostly cloudy. Lows 51-58. Wind NW 5-15 MPH.
THURSDAY: Mostly cloudy. Morning showers possible South Coast. Highs 62-69. Wind NW 5-15 MPH.
THURSDAY NIGHT: Clearing. Lows 43-50. Wind NW to N up to 10 MPH.
FRIDAY: Mostly sunny. Highs 62-69, coolest coast. Wind N to NE up to 10 MPH.
FRIDAY NIGHT: Clear followed by increasing high clouds. Lows 43-50. Wind calm.
SATURDAY: Thickening clouds. Rain potential increases south and west of Boston later in the day. Highs 58-65, coolest coast. Wind SE up to 10 MPH.
SATURDAY NIGHT / SUNDAY: Overcast. Periods of rain and drizzle. Areas of fog. Lows 45-52. Highs 52-59. Wind E to NE 5-15 MPH.
DAYS 6-10 (MAY 25-29)
Expecting low pressure to start pulling away by Memorial Day (May 25) with some partial improvement – less rain, some breaks in the clouds, but on the cool side. Upper level low pressure presents the chance of mainly afternoon showers both May 26 & 27, and a surface low and disturbance may enhance the chance on May 27. Fair weather returns later in the period. Temperatures continue to run on the cooler side through mid period but moderate to seasonable at the end of the period.
DAYS 11-15 (MAY 30 – JUNE 3)
Continued leaning toward a cool, dry pattern to end May and start June with eastern Canadian high pressure the most dominant feature.