First Alert Weather In-Depth: Forecasting winter storms

ROCHESTER, N.Y. (WHEC) — Most Rochesterians would likely agree it’s been a relatively easy winter so far. While there haven’t been many occasions to break out the snowblower, it may be time to start gassing it up ahead of the upcoming week.

First Alert Meteorologist Glenn Johnson is giving readers an inside look at the decision-making process that meteorologists use when dealing with a large-scale winter storm system.

When meteorologists are seven to 10 days out from a possible storm, they look at the pattern recognition. Right now, a storm is way out on the Pacific Ocean, beyond the West Coast. There is not a lot of data on that storm system yet, so they are looking at the big picture: The jet stream and how the northern hemisphere is reacting as it relates to the weather pattern.

Beyond that point, a little bit closer in time to that storm, about five to seven days in advance, Johnson looks at the trends. What is the track on this possible storm system and is that track getting a little closer to Rochester or moving a little farther away? That is going to be a concern of his.

Three to five days out, it comes down to the timing and the type of storm we are looking at here. What is the possibility of sleet freezing rain? Is it going to be snow and specifically what type of precipitation is going to be affecting Rochester? When it is going to be arriving in Western New York?

Three days out, Johnson gets down to the real nitty-gritty of the forecast details. Meteorologists’ big concern is when is the snow going to be starting, what community is going to be affecting and will there be a big snowfall? Do we expect any lake effect snow?

In addition, they look at yellow alerts and that is going to be a concern to the News10NBC meteorologists? The First Alert Weather Team has been focusing on the possibility of a Yellow Alert.