What seemed like a relatively simple forecast just a day or two ago suddenly is a bit more complicated for parts of the region.
Low pressure currently in the Ohio Valley will pass north and west of the region on Friday. A warm front ahead of the system will move through tonight, accompanied by some showers this evening which will become a steadier rain overnight. Temperatures will also rise behind the warm front tonight. By the time you wake up on Friday, temperatures should be in the lower to middle 50s, but won’t go up any further. A cold front will move through during the morning, and it will bring an end to the rain, but temperatures will start falling in the afternoon behind the front. That front will likely stall out once it gets offshore, keeping plenty of clouds around, especially closer to the coast. Saturday looks to be a cloudy, cooler, and drier day across the region.
Late Saturday is where the uncertainty comes into the forecast. A wave of low pressure will begin riding up the stalled out front offshore. How close it comes to the Cape and Islands varies by which model you look at, which has an impact on the forecast. Some models keep the system well offshore, with little to no impact on us. Some models bring it close enough for some rain or snow showers across the Cape and possibly southeastern Massachusetts, and some bring in steadier snow to parts of eastern Massachusetts. No matter what track it takes, gusty north to northeast winds will probably also generate some ocean-effect snow across parts of Cape Cod and possibly Plymouth County. For now, we’re leaning toward the middle ground of the model scenarios, but obviously will keep a close eye on how things progress. High pressure builds in behind the system Sunday night into Monday with dry and cool conditions.
Thursday night: Periods of rain, breezy. Temperatures slowly rising overnight.
Friday: Rain ending by early afternoon, remaining cloudy. High 50-57 in the morning, temperatures drop in the afternoon.
Friday night: Mostly cloudy. Low 27-34.
Saturday: Plenty of clouds, possibly a few breaks of sunshine. High 34-41.
Saturday night: Cloudy, chance for some snow or rain showers across Cape Cod and southeastern Massachusetts. Low 22-29.
Sunday: Snow showers possible across Cape Cod and southeastern Massachusetts, some clearing late in the day. High 32-39.
Sunday night: Clear to partly cloudy. Low 21-28.
Monday: Partly to mostly sunny. High 36-43.