DAYS 1-5 (SEPTEMBER 17-21)
High pressure is now to our east as a trough and associated surface low and cold front approach our region from the west. This means today will be a warm, more humid day, with a sun / cloud mix, but clouds eventually taking over. Showers are likely this evening and tonight as the cold front moves through. A few heavy downpours are possible. This activity exits via Cape Cod by dawn on Friday, leaving us with seasonable, breezy, drier weather for the day. Cooler air will be inbound and you’ll feel that by Saturday as high pressure dominates, but the high temps will be about 10 degrees lower than Friday’s. Then, it’s time to try to solve the mystery that is the timing and behavior of the next unsettled threat. This comes in the form of a low pressure area that moves our way later in the weekend and ultimately tracks south of us, but how far south and exactly when is the question to answer, helping to determine if we get through Sunday without much, if any, rainfall, and how much rain can be around into Monday. Yesterday, I was leaning toward a scenario which holds most of the moisture off to our south and west on Sunday, then allows it into the region Sunday night into Monday when we would see most of our rainfall. Today, I am continuing to lean in this direction, but with reservation that the earlier scenario is still in play.
TODAY: Sun dominant until mid afternoon then more clouds late. Highs 75-82. Wind S 5-15 MPH.
TONIGHT: Mostly cloudy with showers likely. Areas of fog Lows 58-65. Wind SW 5-15 MPH.
FRIDAY: Clouds linger eastern areas early, then sunshine and passing clouds. Highs 68-75. Wind NW 5-15 MPH, higher gusts.
FRIDAY NIGHT: Clear. Lows 40-47 inland, 46-53 coast / urban centers. Wind calm.
SATURDAY: Sunshine can be filtered at times by high clouds. Highs 67-74. Wind variable up to 10 MPH.
SATURDAY NIGHT: Partly cloudy. Lows 50-57. Wind SE up to 10 MPH.
SUNDAY: Mostly cloudy. Highs 65-72. Wind SE up to 10 MPH.
SUNDAY NIGHT / MONDAY: Cloudy. Chance of rain, especially southern areas. Lows 53-60. Highs 60-67. Wind E 5-15 MPH.
DAYS 6-10 (SEPTEMBER 22-26)
The uncertainty of the Sunday-Monday time frame leads to a little continued uncertainty early in this period, but I lean toward a dry-out and fair weather returning early in this period, then a shower threat with a trough swinging through the region in the later September 24 to September 25 time window, followed by a shot of cool, dry weather at the end of the period. Autumnal Equinox: 8:05 p.m. September 22.
DAYS 11-15 (SEPTEMBER 27 – OCTOBER 1)
High pressure dominates with fair weather into mid period before some unsettled weather is possible. Temperatures start cool, then moderate to seasonable or slightly above normal.