8:04AM
DAYS 1-5 ( AUGUST 1-5)
First of August, and first the weekend for discussion. Your pick of the weekend is today, which will feature plenty of sunshine and moderate humidity, light winds and coastal sea breezes. The only “thing” to watch for is the remote risk that enough lift is provided by a sea breeze boundary near or inland from the South Coast to pop an afternoon shower or two. This is a low risk and I would not cancel any outdoor plans over it. Sunday starts with sunshine but clouds will become dominant as the day goes on, this due to a warm front approaching the region. This front may generate a few showers as well, but for now it appears we will get through the majority of the day rain-free, with shower activity most possible late-day and mostly to the west. Some heavier thunderstorms will likely have formed west of the WHW forecast area closer to the warm front during the afternoon of Sunday, and if that is the case, we’ll have to watch for a couple of them trying to survive their way into portions of the region sometime Sunday night. Once the front passes, the humidity spikes and the heat returns for Monday, which will feature a risk for a few showers and storms popping up later in the day mainly well west and northwest of Boston well in advance of a cold front. This cold front will serve as a running board for tropical moisture heading northward up the Atlantic Coast in advance of Isaias, forecast to be a Category 1 Hurricane as it moves out of the Bahamas and parallels the coast of Florida over the weekend, then continuing its re-curve as it weakens to a tropical storm, center staying offshore of Georgia and South Carolina Monday, accelerating and probably moving over eastern North Carolina Monday night and continuing to accelerate while moving northeastward along (anywhere from just inland to just offshore of) the Middle Atlantic Coast Tuesday., at which time we may see tropical showers become more widespread along the front ahead of the system. With the typical track uncertainty to be taken into account, the current official forecast track brings the center of Isaias as a tropical storm, transitioning to post tropical, across southeastern New England late Tuesday night / very early Wednesday, at which time any rain and wind impact would be at maximum. We won’t know the details on either of these until we’re a little bit closer to the event, so the forecast below will reflect the forecast track, but expect tweaks to be made! Either way, expect rapid improvement as the system accelerates away so that Wednesday ends up as a very nice day.
TODAY: Mostly sunny to partly cloudy. Slight risk of isolated showers just inland from the South Coast during the afternoon. Highs 80-87. Wind variable up to 10 MPH with sea breezes.
TONIGHT: Clear. Lows 61-68. Wind variable under 10 MPH.
SUNDAY: Increasing clouds. Risk of mid to late afternoon showers, mainly west of the I-495 belt. More humid. Highs 78-85, coolest coastal areas. Wind SE up to 10 MPH.
SUNDAY NIGHT: Variably cloudy. Risk of showers. Slight risk of a thunderstorm. Humid. Lows 65-72. Wind S up to 10 MPH.
MONDAY: Partly sunny. Isolated showers and thunderstorms possible late-day, mainly outside the I-495 belt. Humid. Highs 86-93, cooler South Coast. Wind S-SW 5-15 MPH.
MONDAY NIGHT: Variably cloudy. Slight risk of a shower or thunderstorm. Humid. Lows 65-72. Wind variable 5-15 MPH.
TUESDAY: Mostly cloudy. Increasing risk for showers and a slight risk of thunderstorms. Humid. Highs 73-80, coolest coastal areas. Wind S-SE 5-15 MPH.
TUESDAY NIGHT: Cloudy. Widespread showers or rain likely. Chance of thunderstorms. Humid. Lows 65-72. Wind variable 15-30 MPH with potential stronger gusts, direction to be determined by the exact track of Isaias.
WEDNESDAY: Mostly sunny to partly cloudy. Humid. Highs 83-90. Wind W-SW 5-15 MPH, higher gusts.
DAYS 6-10 (AUGUST 6-10)
Most of this period should feature nice August weather. A frontal boundary may be close enough for at least some cloudiness and possibly a few showers around August 7 with another disturbance near the end of the period, but overall the majority of the time looks rain-free, but typically humid and warm.
DAYS 11-15 (AUGUST 11-15)
A weak block may form in the atmosphere (low pressure to south, high pressure to north in upper levels). This promotes surface high pressure to the north with a general maritime air flow (northeast to east) at the surface. Whether this persists the entire period is unclear. The general idea would be mostly dry weather but a lack of significant heat with this pattern. It’s also a low confidence forecast.