You’ll get plenty of over-analyzing of the impending foul weather situation wherever you turn for information, so for this post I’m going to simplify the analysis and just explain how I think it’s going to evolve, and what will result in southeastern New England. And we’ll look beyond this as well, of course, out through 7 days. So here goes…
High pressure centered north of New England starts to give way and retreat to the northeast today. While this is going on, low pressure dropping southeastward from the Great Lakes toward the Mid Atlantic will transfer its energy to a frontal boundary offshore. The result will be a series of low pressure areas along this boundary, all moving northeastward over the water southeast to east of New England beginning in the early hours of Saturday and continuing through the late hours of Sunday. The first wave of low pressure will be far enough offshore to keep any steady and significant precipitation out at sea, but an onshore flow with plenty of moisture will bring lots of clouds and the chance of some drizzle and light rain to the region mainly after midnight Friday night into Saturday morning. I’m still expecting dry but cool conditions for Friday evening Halloween activities. A second low pressure wave will develop a little more and come just a little closer, bringing a better chance of rain to southeastern and eastern MA, possibly as far west as RI, and into southeastern NH as well. Most of this will occur during Saturday afternoon and evening. Though we will be feeling a chill, the air will still be too warm to support any snow, so this event will be rain. The final low pressure area will become the strongest, but will likely pass too far east to bring steady or heavy rain with the exception of Cape Cod early Sunday. Only rain showers and possibly snow showers will take place over the remainder of the region as cold air continues to work in from the north. At the same time it will also be drying out, and this may limit the rain/snow shower activity. What will take place is increasing northeast to north winds during the course of the weekend so that by Sunday much of the region is blustery with very gusty winds, strongest in higher elevations and in the coastal plain. By Sunday night, we’ll clear out as the final storm moves away.
Monday will be a bright but chilly day as low pressure continues to distance itself from New England and high pressure tries to build in from the west, the core of it passing southwest of New England. This high will then move offshore allowing a warm-up to take place Tuesday and Wednesday. A cold front will approach from the north by Thursday with some increase in clouds and a chance of rain showers. At 7 days away, this is subject to some change.
SOUTHEASTERN NEW ENGLAND FORECAST…
TODAY: Sunshine followed by increasing cloudiness. Highs in the 50s. Wind E up to 10 MPH.
HALLOWEEN EVENING: Mostly cloudy. Temperatures 45-50. Wind E up to 10 MPH.
TONIGHT: Cloudy. Areas of drizzle and light rain mainly after midnight favoring coastal areas. Lows 40-45. Wind ENE 5-15 MPH.
SATURDAY: Cloudy. Areas of fog and drizzle and a chance of light rain through midday. Better chance of rain afternoon especially southeastern to eastern MA and southeastern NH. Temperatures steady in the 40s. Wind NE 10-20 MPH, higher gusts coastal areas.
SATURDAY NIGHT: Cloudy. Rain likely in the evening, heaviest near eastern coastal areas. Lows 35-40, lower 40s South Coast / Cape Cod. Wind NE to N 15-25 MPH, higher gusts especially coastal areas.
SUNDAY: Cloudy with rain likely Cape Cod through midday. Mostly cloudy to partly sunny elsewhere with scattered rain showers early then only a slight chance of rain/snow showers during midday and afternoon. Highs in the 40s. Wind N 15-25 MPH with gusts 35-45 MPH, possibly higher some coastal areas and higher elevations.
MONDAY: Sunny. Low 30. High 50.
TUESDAY: Partly sunny. Low 40. High 60.
WEDNESDAY: Partly cloudy. Low 50. High 70.
THURSDAY: Variably cloudy. Chance of PM rain showers. Low 55. High 65.