First Alert Weather In-Depth

ROCHESTER, N.Y. – Sometimes when looking forward in time, we have to look back time.  In weather this gives us a sense of how dramatic a change can be for Western New York.  The maximum temperature over the last seven days, for the end of January, has been very reasonable. Most of the time we had temperature readings in the 30s, in fact, Sunday we reached 42 degrees.  However, the first wave of the cold air came in Monday and continued today.

News 10NBC First Alert meteorologists are tracking the Arctic air and it is definitely on the move. We know the north pole is the place for the coldest weather and we have a polar jet that surrounds that Arctic air. Once in a while that jet stream, even though it is very strong and acts like a wall on the bitter cold, it will weaken and the extreme temperatures will push to the south.  Sometimes this is called the polar vortex. Right now a chunk of that cold air is advancing into North America. The sheer weight and density of that cold air is propelling the frigid air south and will arrive over the next couple of days. If we pinpoint one specific time in the future for Rochester, it will be Friday night that we feel the harshest of the weather. The air temperature is going to be near 5 degrees, wind speeds could be pushing 25 to 30 mph.  As a result, the combination of the temperature of the wind, that is what we call a human comfort index or the wind chill index, will be in the range of -15 degrees.

On the positive side, we can look ahead to spring!  The vernal equinox is Monday, March 20th and that is just is 48 days away. Not that were counting the days!