DAYS 1-5 (MAY 4-8)
A warm front goes by early today with patchy clouds, otherwise sun becomes abundant and a southwesterly air flow behind the front with high pressure over the Mid Atlantic results in a warm-up with fair weather, but also increased wind and as a result an increase in outdoor brush fire danger. This continues Tuesday as high pressure builds in the western Atlantic off the US East Coast. Clouds increase later Tuesday as a result of a cold front approaching from the west, but it will stay far enough west so that we stay rain-free. It is Wednesday when this front will make a pass across New England with showers likely, and even the chance of a few thunderstorms embedded. Timing of shower and storm chances will be fine-tuned over the next couple updates. While Wednesday is still a mild day, once the cold front goes by, Thursday will turn cooler. The frontal boundary is expected to slow offshore while a wave of low pressure travels up along it. One change from yesterday’s ideas is that the front appears it will be just far enough offshore and the low pressure wave flat enough so as to keep most of the rain passing offshore as well – maybe clipping southeastern areas – which is the scenario I’m leaning toward at this point. However, I’ll monitor any trends here and update as necessary. By Friday, cooler weather is re-established, and I cannot rule out a pop-up shower from diurnal clouds triggered by sun-heated land under cold air aloft as an upper trough of low pressure moves into the region. Most areas should remain dry, however, as we get to the end of the work week.
TODAY: Patchy clouds early, otherwise lots of sun. Highs 58-65 South Coast, 65-72 elsewhere. Wind SW 5-15 MPH.
TONIGHT: Mostly clear. Patchy ground fog. Lows 48-55. Wind SW up to 10 MPH.
TUESDAY: Sunny to partly cloudy through mid afternoon then increasing clouds mainly west of I-95 later in the day. Highs 58-65 Cape Cod / Islands, 66-73 eastern CT and RI to MA South Shore and Cape Ann, 74-81 elsewhere. Wind SW 10-20 MPH.
TUESDAY NIGHT: Partly cloudy to mostly cloudy. Lows 52-59. Wind SW 5-15 MPH, higher gusts.
WEDNESDAY: Variably cloudy. Showers possible, chance of thunderstorms, favoring areas west of I-95. Highs 66-73 except cooler South Coast to MA South Shore. Wind SW 5-15 MPH, higher gusts.
WEDNESDAY NIGHT: Mostly cloudy. Showers likely, especially in the evening. Patchy fog. Lows 50-57. Wind SW to variable up to 10 MPH.
THURSDAY: Mostly cloudy. Chance of rain, mainly RI and southeastern MA. Highs 58-65. Wind variable 5-15 MPH.
THURSDAY NIGHT: Variably cloudy. Lows 40-47. Wind N to NW 5-15 MPH.
FRIDAY: Sun / cloud mix. A pop-up shower possible. Highs 56-63. Wind NW 5-15 MPH, higher gusts.
DAYS 6-10 (MAY 9-13)
Blocking pattern re-establishes. Cooler weather favored with pop-up showers underneath an upper low early in the period (May 9-10 weekend). Watching for a more widespread rain mid or late period but uncertain on that possibility this far in advance.
DAYS 11-15 (MAY 14-18)
Blocking pattern holds as does the cool overall regime but looks drier over wetter at this time.