Last fall the "official" forecast for our winter was for mild temperatures and less snow than normal.
My forecast, on the other hand, was for a cold winter with more snow than usual, which is how it turned out.
But it's another year, and after a cool, wet summer many of us are wondering what's in store for this winter.
The Climate Prediction Center is forecasting a mild winter with less snow, but the Farmer's Almanac is forecasting brutal snow.
I'm personally, again, more worried about the cold.
I don't think there is any doubt that this past summer will go down as one of the coolest and rainiest on record.
2009 is the only summer in history, since the late 1800's, that is in both the top-10 coolest and top-10 wettest. But do summers like this lead into cold, snowy, winters? Or perhaps a mild and wet one?
I looked at the coolest summers from the past to find out what the following winter was like.
On average, temperatures were slightly milder than normal, and snowfall significantly less. Then I searched back through the wettest summers from the past and found that the following winter, on average, ended up slightly colder than normal with slightly less snow.
Since none of these summers were on both the coolest and wettest list, I totaled all of them up. The following winters averaged right at normal for temperatures and with about a half-foot less snow.
Since the winters following these summers were all over the place with the weather, and none of them had similar overall patterns to what we are seeing now, I did not put much stock in them.
So, let's see what is probably going to control our winter this time. We have to look worldwide to see the big picture and that means going into the Pacific, first of all.
Unlike last winter, when we had a weak La Nina, an El Nino is developing right now. That's warm water near the equator, and has gotten the reputation of giving us a warm winter. But we've found that no two El Nino's are alike. A moderate to strong El Nino, would lead to a mild winter for us. A weak El Nino, like I'm fairly confident of, typically leads to a colder than normal winter for the Midwest.
Some changes in the water temperatures of the North Pacific are leading me to lean toward a cold winter also. But while the Pacific conditions many times dominate our winter pattern, there is an affect in the Atlantic also. It's interesting that this year the water set-up would lead to what we call a "block" over the Atlantic. This forces the jet stream to shift north along the eastern seaboard, where the main storm track would be. It could be a brutal winter for the east.
This pattern would lead to a colder than normal winter for us, and that many times leads to more snow. However, with the storm track expected to be east of here most of the time and since this past summer has lead to a cooler than normal water temperature in Lake Michigan, we will probably get less lake-effect than we normally would.
Let's put it all together. Here is my official forecast for the winter of 2009/2010:
I am forecasting temperatures for December through February to be 25.4 degrees, which is two degrees colder than normal. This is still not as cold as than last winter, though. As for snowfall, I am forecasting 77 inches of snow, which would be just about normal and also about what we had last winter.
I am worried about one thing, however. Two of the nine winters that I looked at as "similar" in the overall pattern to this coming winter are 1976/77, and 77/78.
For those that remember, these were brutal winters with tons of snow.
That would be the worst case scenario for this coming winter but, at this point, I doubt we'll see a repeat.
I will keep looking at things though, and tweak my forecast again just before Thanksgiving.