Our recent summer preview continued on Friday, setting records across southern New England, but the warm stretch is on borrowed time.
An expanse of cool air has been building across the Canadian border and will be pushed southward in response to strengthening high pressure over Quebec that builds into Atlantic Canada, pushing some of that cool air southwest into New England.
First, the records: Boston broke a 78-year-old record just after noon — the thermometer read 83 degrees. Worcester reached 84, Providence 87 degrees and Hartford 89 degrees, all new highs.
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The opening volley of cool air comes Friday, when the sea breeze kicks in at the coast around midday – it’s, of course, common for a sea breeze to bring a precipitous drop in temperature, but the change will be especially pronounced Friday afternoon, with coastal communities like Boston dropping from around 80 degrees to the middle 50s by late day!
Further inland, the new air takes longer to arrive, but the Interstate 95 and 495 corridor will feel the big change in air by late day and early evening, with areas further west experiencing a more gradual change of air Friday night. This change of air benefits those who enjoy exercise or have respiratory ailments, as the pollution and haze of Thursday and Friday will mostly be swept west as the new air off the ocean will be cleaner. For most, Friday night low temperatures drop to the 40s, under partly cloudy skies, and the onshore flow of wind Saturday will ensure a much cooler day across the board, with highs in the 50s at the coast, 60s inland and 70s reserved for the western half of New England.
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Most of Saturday looks dry, but a weakening disturbance tracking northeast from the Mid-Atlantic will spread showers into southern New England Saturday evening and night, then as the disturbance weakens overhead Sunday, occasional light showers will crop up. Right now, it looks like the most focused showers Sunday will be on Cape Cod in the morning, then near the coast later in the day, but anything after the morning Cape rain is likely be scattered and quite light, meaning those who are okay with a few light passing showers at times could still make outdoor plans work, though the expectation for some raindrops at times needs to be there.
A stronger disturbance prompts a storm over the Great Lakes Sunday to drift east and encourages new rain showers to develop over New England for Patriots day, with passing showers and cool temperatures in the 50s looking likely for the Boston Marathon.
What once looked like a disturbance quick enough to bring gradually improving weather and a diagonal tailwind has slowed sufficiently to change that forecast from what it was early this week – now looking like the east wind will be slower to turn, and that’s a big impact for runners, as it means a headwind instead of tail.
That said, the overall wind speed will be fairly light at 5-10 mph. The middle and end of next week brings some improvement for those trying to enjoy a few days of April’s school vacation week for many kids, with Tuesday bringing some modicum of improvement and Wednesday to Friday looking good before the chance of showers rebuilds next weekend, at the end of our First Alert 10-day forecast.