ROCHESTER, N.Y. — When looking at the future of large-scale storms, it amazes me how much of an improvement the meteorological community made over the years. The most recent storm is approximately 2000 to 3000 miles away from Rochester, but even at that distance we know it will have an impact on our Western New York weather.

The calculation for any forecasting analysis starts at seven to ten days from the arrival time. At this timeframe we are looking at pattern recognition. This includes the overall hemispherical pattern and whether the pattern is conducive to this type of storm. Then, with more analysis of the computer modeling, it is at five to seven days from arrival that we are looking for the trend. Is the trend for this large-scale pattern holding?  Are there any subtle changes?  Is there enough cold air projected to come into that pattern? 

If there is very little or no change then we move to the three-to-five-day timeframe. At that point, we analyze the specific timing and the type of storm. Will it have freezing rain, snow or even ice pellets?  Once we have arrived at the one-to-three-day timeframe we can then get very specific about the forecast details including the hour-by-hour weather elements.

I like to use the analogy that weather forecasting is like driving on the New York Thruway. When you see off in distance, but it looks blurry. You know it is an exit, but you cannot quite make out the details. But as you get closer it comes into focus and clarity makes for a better forecast.