The summer 2009 forecast was a bust on the temperature. We'd predicted a slightly warmer summer and drier summer on the strength of La Nina which was in force during February 2009. This again demonstrates our need to get the El Nino phase right. At the time, the La Nina was supposed to continue. We followed this logic and paid a price for it. Although, the summer forecast for precipitation was below normal, June and August were, but July was above normal enough to ruin the forecast. I will say that region-wide that our forecast of drier was probably looking OK.
As for winter, it is a different story. Last year we missed on the snow, in fact it was one of the least snowiest winter ever. As far as temperatures were concerned we did very well. We forecast the temperatures to be slightly above normal and they were. December was colder than normal, January close to normal, and February quite a bit warmer than normal. The precipitation was just less than 0.5 standard deviations below the normal, and we'd forecast it to be within the range of normal.
Winter 2009-2010 should be within the range of normal, but on the warm side. We're basing this on the warm SST's and weak El Nino developing. I expect El Nino will be weak. CPC is going for warm to quite warm based on global warming and their reflexive response to put a warm signal in with every El Nino. In fact a central Pacific El Nino has historically brought cooler winters. This is why we've been hedging for a few weeks. There are warm waters in the central and Eastern Pacific and that is making things uncertain. However, to wait longer to go with a forecast will not make it a long-range forecast anymore. So we're going with warmer, normal precipiation and close to normal snowfall. It can't be any less snowy than last year.
Here are the numbers for the summer 2009 recap and the winter 2009-2010 forecasts, 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.
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 or winter 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.