DAYS 1-5 (SEPTEMBER 5-9)
The large scale pattern across the country features a ridge of high pressure in the central US, which leaves our region in a northwest flow pattern on the east side of the ridge, with more amplification as an upper trough sits over our region now and drifts eastward into Atlantic Canada and the adjacent waters through the weekend. The flow around the back side of a surface low south of Nova Scotia will send some cloudiness into our region at times today and part of Sunday, which will be added to at times by diurnal cloud development. Pop-up shower chances are greatest west of I-95 this afternoon with limited coverage. Any area that does see a shower would only have it last a short time before it moved on. A trough may bring a quick-moving batch of showers in the pre-dawn hours to southeastern NH and northeastern MA Sunday, and the chance of a diurnal pop-up shower that day dwindles to nearly zero. Monday’s weather features more sunshine and less cloudiness and the rain chance drops to nil. So all in all, the holiday weekend is not bad, featuring mostly dry weather, a cooling trend on a north to northeast flow, and low humidity. Reminder that the north to northeast fetch will create rougher surf, some larger swells, and rip-current risks especially at north-facing and east-facing shores through the weekend. A trough swings through first thing Tuesday with clouds and perhaps a shower, and then clouds increase from the northwest ahead of the next approaching disturbance Wednesday. Guidance has trended faster in the medium range with that disturbance, indicating a shower chance may exist before that day is over. I’m leaning in that direction based on the type of pattern we will be in.
TODAY: Sun / cloud mix with clouds more dominant. A passing shower possible. Highs 68-75. Wind N to NE 5-15 MPH.
TONIGHT: Variably cloudy. Shower chance is best overnight southeastern NH to northeastern MA. Lows 53-60. Wind N up to 10 MPH.
SUNDAY: Sun / cloud mix with sun more dominant. Highs 68-75. Wind N to NE 5-15 MPH.
SUNDAY NIGHT: Mostly clear. Lows 48-55. Wind N up to 10 MPH.
MONDAY – LABOR DAY: Sun dominates. Highs 71-78. Wind NW 5-15 MPH.
MONDAY NIGHT: Variably cloudy. Lows 51-58. Wind W 5-15 MPH.
TUESDAY: Clouds and a possible shower early, then clearing. Highs 70-77. Wind W shifting to N 5-15 MPH.
TUESDAY NIGHT: Clear. Fog patches interior low elevations. Lows 50-57. Wind variable under 10 MPH.
WEDNESDAY: Increasing clouds. Shower chance returns late-day. Highs 68-75. Wind variable up to 10 MPH.
DAYS 6-10 (SEPTEMBER 10-14)
Disturbances in a northwest flow are roughly timed to pass through early September 10 and late September 13 to early September 14 when brief shower threats occur, otherwise a mainly dry pattern with somewhat variable but overall near to slightly above normal temperatures.
DAYS 11-15 (SEPTEMBER 15-19)
Up-and-down temperature pattern with a couple unsettled weather episodes with quick-passing systems as the pattern remains generally the same in the waning days of astronomical summer.