The reason we look at El Nino and La Nina episodes is because it has a direct impact on the overall weather pattern across North America. It gives us guidance. During La Nina, we tend to see colder winters and a higher likelihood of stormy (wintry) weather. Temperatures during past La Nina winters look like this:
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La Nina influenced winters have shown in the past:
- Temperatures: The weakest episodes of La Nina have produced colder temperatures averaged from Dec-Feb. The stronger the episode the less likely it became
- Snowfall Totals: During the weaker La Nina episodes during winter months, higher snowfall totals were more common. The stronger the episode, the lower snow totals tended to be as a result. Some of our historically highest snowfall events have occurred during weak La Nina influenced winters.
- Precipitation Totals: Total precipitation (rain, sleet, snow, freezing rain) varied quite a bit for each La Nina winter but also trended toward being at or above average.
NOAA will be posting new images on Thursday and I will update them when they are released. Here is what they currently forecast for the Oct-Nov-Dec period which finished up Fall and begins Winter.
One thing that can have a very large impact on the winter weather pattern is where the actual jet stream will set up for most of the season. It can make a big difference between cool & mild, snowy/icy/rainy across the Local 6 area alone. We've seen it time and time again.