Longer Range Forecast...

Some interesting developments have occurred in the longer range forecasts of the ECMWF and GFS. One of the main things that I look for in the models longer range forecast hours is the general upper level flow patterns. In the 240 hour timeframe, the ECMWF is forecasting the development of a large upper level trough as the ridge in the Gulf of Alaska restrengthens (suggesting to me that the Polar vortex will remain weaker through the long-range). This upper level trough will show up as a slightly negative PNA teleconnection in the forecasts. With this kind of a jet stream configuration, strong southwesterly flow in the upper atmosphere is likely over our area. This is a pattern favorable for storm systems to transverse the Midwest and Central Plains. In the longer-range, I would anticipate near normal precipitation, due to the fact that most of these storm systems will be diverted to the north and west of the area. So far, this is an atmospheric set up very similar to the fall of 2010. The rather warm fall of 2010 eventually gave way to the very stormy and cold winter of 2010-2011. One forecast doesn't mean anything, but if this is consistent, I would bet on seeing a winter across the United States that will be very similar to the winters of 2009-2010 and 2010-2011. In the meantime, what it means for us is that we will likely continue with a warmer than normal, with a possible slight re-strengthening of the current moderate drought conditions.