NEW YORK (AP) — Severe winter weather across the northeastern United States, a partial government shutdown and security concerns in parts of western Mexico converged to make Monday a challenging time for air travel. Thousands of U. S. flights were canceled or delayed on the East Coast as a powerful snowstorm upended daily routines in Boston, New York, Philadelphia and other major cities. Airlines also suspended or adjusted service to destinations in and around Mexico’s Jalisco state as in...