Polar vortex stirring as fall arrives. Here's when to expect first frost in NY

The polar vortex is stirring up, bringing the earliest hints that the weather is changing as autumn has officially arrived.

In the short term, this means gradual cool-downs and a more active storm track across the northern United States. But not everywhere will feel the chill quite yet. In Western New York, highs are still expected to reach into the 80s this week, with overnight lows mainly in the upper 50s.