Extended outlook: Big warm-up, early taste of summer on the way for Boston

New Englanders just might get a sneak peek of summer-like weather sooner than they think. An approaching warm front and large-scale shift in weather patterns are likely to drive temperatures into the 70s — about 5 to 10 degrees above normal — to start the first full week of May, and even higher as the week progresses. A sizable bend in the jet stream toward the north — known as “ridging” — should influence warm air advection across New England starting Monday, with a southwesterly flow behind the passing surface...