A large dome of high pressure – fair weather – is flexing its muscle over Eastern Canada today, pressing enough dry air into New England to keep rain safely south of us, though some clouds continue riding overhead at high altitudes, dimming the sun over Southern New England at times.
All the while, a northeast wind not only is carrying cool air southward from Canada, but also is moving across ocean water that is only in the lower 50s, meaning Friday’s warmest air temperature won’t exceed the 50s near the coast and 60s inland.
Cool overnight temperatures Friday night will tumble into the 40s for most, but 30s in Northern New England, where a frost and freeze is a potential even as clouds gradually thicken overhead. Saturday will dawn dry for most, though rain will be advancing northeast across Connecticut between 6 and 8 a.m., then the Boston area between 10 a.m. and noon, not reaching Portland, Maine, until mid-afternoon.
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Once the rain starts, it’ll keep temperatures cool and fall lightly, perhaps with an occasional burst of moderate rain in Western New England. This may not cancel all outdoor plans but will keep them damp, for sure.
Sunday brings a totally different air with humidity increasing, breaks of sun driving temperatures well into the 70s and an approaching cold front triggering scattered showers and thunderstorms, especially during the afternoon. Behind the front, Monday should be lovely, and aside from the chance of a few midweek showers, most of next week into Memorial Day Weekend is looking good in the exclusive Early Warning Weather 10-day forecast with slowly rising temperatures.