Winter 2011-2012 Forecast: We may be looking at a repeat of last winter as La Nina looks to reamin in place and strengthen again. Initially we'll say Winter 2011-2012 could go one of two ways. If we go back to La Nina and of G type, we would see a more zonal flow over the east and that would mean a much warmer than normal winter for us. If however, we get a lot of blocking in the Alaska sector, I expect a cooler than normal winter. I favor the latter scenario as SSTs are warm in the Gulf of AK (and getting warmer) and LA Nina should see both team up to provide a "blockfest" not only in the Atlantic, but in the Pacific. This will result in another cooler winter, and normal to above normal snows. That is because blocking pushes cold air out of the arctic and onto the North American Continent. I expect precipitation to be below normal if colder by a similar amount. Now, CPC is going for warmer again! By 0.5 standard deviations and close to normal in precipitation, we say cooler than normal.
Summer 2011 Recap: We cleared out of the strongest La Nina in quite a while. Since we are in the cool PDO phase, it is possible we could stay in a prolonged La Nina. It's happened before. It looks like it's on the way again. Most computer models bring us back to La Nina. This summer has been warm (2.4 F above normal) and humid and a bit on the dry side of normal but not by much. Three straight summers had been soakers. Our forecast of drier has been on so far. Spring blocking seems to be a pre-cursor to dry weather. Past statistics also indicated that the conditions that exist now would favor a warmer summer. I have not run the numbers yet, but cold winters are followed by warm summers and I suspect again, the La Nina connection. we forecast warmer than normal by 0.5-1.0 Standard Deviations. Thus, we were a little too shy in our warm forecast. Again, we forecast drier than normal, and the past stats agree with drier for this summer. This is especially true as the SST anomalies have returned to G-type. Summer and Fall G-type months are running 17 dry, and 0, YES THAT IS 0, wet. G-type anomalies really tilt heavily toward warm and dry. La Nina favors a long dry spell sometime after 4 July through August. In short, for the last year our LONG RANGE FORECASTS have kicked butt!
Here are the numbers for the winter 2011-2012 forecast and the summer 2011 recap, for Columbia Missouri. The standard deviation (+/-) represents what we call the typical range for that value, and 70% of years should lie within this range. These are generally reliable for most of mid-Missouri from the Ozarks to the Iowa border and Eastern MO. Also, this year I've included verification statistics, see Lupo et al. 2008 - the link is Kelsey II on the main GCC page. Forecast scoring can also be found there, 2 points for a perfect forecast, and 0 for a bust.
NOTE: These are our forecasts and they are based on the information found in several publications on the Climate Group's website (see Climate Variability section). One should not consider that these will be 100% reliable. Also, they forecast the AGGREGATE statistical character of the summer (June, July, August) or winter (December, January, February) season. This does not mean that warm and cold spells, wet and dry spells will not all occur in one month or season. Please use with caution. If you have any questions contact me at: