Monday, November 14, 2011

Positive EPO Shows Thanksgiving Will Be A Warm One

Classic signals of a positive phase EPO index are showing up on the long range 11-15 day 850mb temperature anomalies. In the Alaska region, we have much below normal temperature anomalies as a trough of low pressure will likely be in place if this verifies. Canada will have a high pressure over the region, accompanied by warmer temperatures as shown on this model. This solution of a positive EPO has been trending (showing up over and over again) for several days now. But is this actually plausible?
12z Models EPO forecast
The GFS model (the image on top), and the GFS' ensemble members both agree on the EPO staying strongly positive, thus keeping the East US warm. The ECMWF, while it doesn't go out as far as the GFS, actually goes higher than the GFS for this EPO forecast, though not visible on this particular graph.

Something we have been talking about is how winter is projected to 'start' in Mid December. This +EPO is another factor that will have a say in the start of the cold weather, and will be something watch going into December. We still think that will happen, and will update you as we continue to go through November.

If you are still confused on what the positive phase EPO does, look at the top image for more information.