So are they really accurate? Everyone wants to know what the next season holds months in advance. Curiosity mostly, although some jobs depend on it, especially in the energy industry. What I can tell you is this. Take them with a grain of salt. Yes we’ve come a long way in our computer processing that I mentioned in another blog, but the benefits of that is mostly in the short term, not long term. We still use these models and a different suite of them that monitors ocean patterns and oscillations. These coupled with current ocean temps and entities like El Nino or La Nina are used in combination with the analogs of past weather. Together it paints a picture of what we should be expecting. The forecast is much more broad however, large geographical areas are assigned a general +/- few degrees above normal and the same with precipitation. Beyond that, the science is limited. For example, it’s not possible to say in exactly 5 months and 10 days from now, the high will be XX degrees with a low of XX degrees, wind out of the south, scattered showers. Those are all reserved for the short-term forecasts. Any outfit that claims otherwise is taking you for a ride.
That said, there is some skill overall in seasonal forecasts, but it’s barely above the baseline. Meaning it’s barely worth doing verses not doing, just a slight advantage. Some are better at it than most and can pick out things in the long range pattern that should affect the weather over an area one way or another. There are a couple of big players in this game. The rest are trying, but come up short most times. Even the best guys will get it wrong or parts of it wrong anyway. It’s the nature of the game. So the bottom line is this, make a note of it but don’t bet the farm. Before you know it, you’ll be asking about the next season anyway.