Saturday, May 31, 2014

What Are The Models Saying This Winter? - CMC2 Model

This is a continuation of this series of posts, where we are analyzing long range climate model projections for the beginning of the winter of 2014-2015. This post will feature the CMC2 model.

The temperature forecast from the CMC2 model is a toasty one. We see warmer than normal conditions prevailing across the heavy majority of the country, especially around the Midwest and Northeast regions. There is a slight cooler than normal projection in the Southern Plains, but warmth definitely triumphs here. This forecast is very reminiscent of a typical El Nino temperature pattern, where warm weather stays in the North US and cooler than normal temperatures prevail in the South US. It would definitely be a welcome turn-around from what we experienced last winter.

The precipitation forecast for December 2014 from the CMC2 model is not as similar to an El Nino precipitation pattern. We see more or less neutral precipitation anomalies across the West Coast, but the real story is the shifting of drought-esque precipitation anomalies from the West to the Central US, as the CCM2 model predicts would happen to kick off the winter of 2014-2015. Typically, these dry anomalies would be centered in the Ohio Valley for an El Nino winter, not so far west. The El Nino pattern does briefly show itself as a wet start to winter in the East, but i'm not sold. I believe this model needs more time to solidify its forecast; I am not investing much confidence in it.

Lastly, we see the forecast of z200 anomalies for December 2014 from the CMC2 model. We're going to focus on the contour lines over the northern Hemisphere. In this forecast, we see the contour lines arching northward over the west coast of North America, signifying ridging/high pressure in that area. Typically, this would mean a chilly winter for the East US, but the arching of these contour lines extends east into the Central US, meaning high pressure would be favored over low pressure for that part of the country. This map does support the warm temperature forecast we saw earlier in this post, and such a forecast would be nearly a complete-180 from this past winter.

Additional model forecasts will be discussed in the near future.