As I write this, the numbers for the month are not quite all in, but even without the last three days of data, I am pretty confident in saying that September 2009 will go down as the warmest September on record. The question is just how many records will be broken and by how much. As much as I want to discuss this remarkably warm month, we are going to have to wait until next week so I can crunch all of the numbers.
In the meantime I think it is time for us to take a look at what the weather department might have in store for us for the rest of the fall and winter. I have heard that the Old Farmers Almanac has come out swinging saying that we are going to have another really cold winter, and maybe they will be right. But let’s take a look at what is currently going on with our global weather and see what it might tell us about the next two to six months.
First of all, I guess the big weather news item that may have an effect on our weather during the fall and winter is the El Nińo event that is currently taking shape over the Pacific Ocean. Just what is El Nińo? Well, I have written about it in the past, but just in case you missed those articles, or your memory just isn’t like it once was, here is the Reader’s Digest version.
El Nińo is an atmospheric and oceanic disturbance in the Pacific Ocean that occurs roughly every seven to 14 years. Its name means “the Child,” because it originally was noticed appearing near the Christmas season but we now know this is not always the case. During an El Nińo event, warm surface waters flow from the central Pacific towards the eastern Pacific, which suppresses the cold upwelling of the Humboldt Current off the coast of South America. This then leads to a reversal of the trade winds and disrupts the normal flow of weather across the Pacific.
This is the key point to El Nińo; it affects ocean and atmospheric circulation over half of the globe and it just happens to be the half of the globe that is upwind to us! The current El Nińo is considered to be a weak one, but forecasts are flipping between it becoming a moderate to strong El Nińo event over the upcoming fall and winter months.
What does an El Nińo fall and winter usually mean for our region of the world? During the fall there does not seem to be a statistically significant effect from El Nińo, but during the winter there is a very good chance that Western Canada will see warmer-and drier-than-average conditions.
If we look at what Environment Canada is forecasting for this fall and winter, it looks like they are predicting a typical El Nińo fall and winter. They are calling for near-average temperatures and precipitation during the fall with above-average temperatures and precipitation during the winter.
Over at the Old Farmers Almanac they are going in the opposite direction with a call for above-average temperatures to start the fall (October) and then progressively getting colder as the winter wears on. They are also calling for near-to above-average amounts of precipitation for both the fall and the winter. Now keep in mind they were the ones who called for a cold, wet September.
The Canadian Farmers Almanac is calling for some very interesting weather this fall. They appear to be calling for a mixed bag of weather during October, with cold and warm periods predicted, along with showers and even thunderstorms. They are even calling for a dust storm late in the month. During November things get even stranger as they call for plenty of rain and/ or wet snow along with thunderstorms late in the month. Now that would be interesting!
Finally, here at the Co-operator, I think I have to go with Environment Canada and the idea that we will have an El Nińo winter. Looking at the statistics from previous El Nińo winters we have about a 60 per cent chance of seeing above-average temperatures, 20 per cent of seeing near-average temperatures, and a 20 per cent chance of seeing below-average temperatures. Precipitation is always tough to forecast, but during the winter, if we have above-average temperatures, we usually have below-average amounts of precipitation.