A neutral ENSO phase remains in place across the Equatorial Pacific Ocean at this time. Sea surface temperatures are slightly cooler than average across parts of the east-central and eastern Pacific. The latest long-range climate models continue to indicate that the present neutral phase will transition into a La Nina phase over the next few months.
Currently, there is about a 60 percent chance that a La Nina phase will be in place during the upcoming fall and winter. Needless to say, if this La Nina does indeed develop, it will likely have an influence on temperatures and snowfall across parts of the United States this winter. As for the September temperature outlook, slightly above normal temperatures are predicated across portions of the Rockies, Desert Southwest, Northeast, Mid-Atlantic, Ohio Valley, Tennessee Valley, and Midwest. These regions of the country will likely see a surplus of late season cooling degree days by between 20 and 60.
Energy costs with respect to cooling will also be at least slightly higher than average throughout much of these areas of the country. Temperatures on a whole are forecast to average closer to normal across the Plains, Gulf Coast, and West Coast during the month of September.