New Yorkers are basking in a warm spell that snapped a chilly stretch not felt in the city since 1982 – but they shouldn’t expect the break to last, with temps set to drop again by the end of the week. Temperatures are expected to hit as high as 70 degrees Tuesday and again be in the mid-60s Wednesday — before falling to the mid-50s or lower to wrap up the work week, AccuWeather senior meteorologist Matt Benz told The Post on Monday. Thursday will have a high of 57 degrees with a chance of rain,