A much cooler and wetter week is upcoming for the region.

We’ve got one more hot and humid day today with high pressure offshore, but big changes are on the way. A cold front will move in tonight, possibly accompanied by some showers and thunderstorms. The front is expected to stall out near or just south of us on Tuesday, with much cooler weather likely behind it. Some additional showers are likely during the day on Tuesday. A wave of low pressure riding along the front will bring in some rain for Tuesday night and Wednesday, possibly some heavy rain, especially south of the Mass Pike. Despite how wet it has been around here for the past year or more, we’ve actually been rather dry for the past month or two, and can use the rain, though maybe not all at once. High pressure briefly brings in drier air for Wednesday night and part of Thursday before Debby impacts the region.

As of 2am, Hurricane Debby was centered only 40 miles west of Cedar Key, Florida, moving toward the north at 12 mph. Maximum sustained winds were near 80 mph. By the time most of you read this, Debby will have already made landfall in the Florida Big Bend region. Storm surge flooding will gradually die down this morning, and winds will steadily weaken, but rain will continue across the Southeast for several days, with widespread significant flooding likely from northern Florida into the Carolinas. Once inland, Debby is likely to stall out as steering currents collapse, and meander around in the Southeast, resulting in all of that rainfall. While Debby is doing that, some of the moisture from it will get drawn northward, interacting with that stalled frontal system, bringing us some rain for Friday and Saturday. In fact, we could be looking at quite a bit of rain. The wildcard is Debby itself. Some models have Debby dissipate across the Southeast, some bring it back offshore then into the Carolinas before heading up the coast in a weakened state, and some keep it inland and weak, then bring it up here. If it gets up here, there is even more uncertainty, as some models bring what’s left of the circulation right across southern New England, some bring it south of New England, while strengthening as it becomes extratropical, which introduces even more issues here, including gusty winds, not to mention temperature forecasts depending on the where the storm tracks. What you see below is our “best guest-imate” right now, but obviously this is very low confidence based on everything we just mentioned. A cold front will move through Saturday night, kicking whatever is left of Debby out to sea, and bringing drier weather in for Sunday.

Monday: Mostly sunny, clouds start to increase late in the day. High 85-92, little cooler across Cape Cod.
Monday night: Partly to mostly cloudy with showers likely. Low 65-72.
Tuesday: More clouds than sun, any showers end early, possibly redevelop towards evening. High 72-79, early, cooler in the afternoon.
Tuesday night: Mostly cloudy with showers likely, possibly heavy. Low 56-63.
Wednesday: Morning clouds and showers, some afternoon sunshine. High 71-78.
Thursday: Early sun, then clouds return in the afternoon. High 72-79.
Friday: Cloudy with a chance of rain. High 70-77.
Saturday: Mostly cloudy with more rain possible. High 72-79.
Sunday: Intervals of clouds and sun. High 73-80.