Temperature and Precipitation Composites for December - February 2004

The Climate Diagnostics Center (CDC) website was used to determine years that matched similar upper level wind flow patterns throughout the entire Northern Hemisphere to what occurred this past October, 2003 (Fig. 1).  After searching through flow patterns from 1948 to the present, I made average composites of temperature and precipitation anomalies for the December, January, and February months that followed.  The following years matched similar flow patterns in the Northern Hemisphere: 1999, 1992, 1987, 1974, 1965, and 1964.  

The following figure is a plot of the upper level wind flow patterns for October, 2003. 

                                                                Fig. 1. Northern hemispheric flow patterns for October 2003.                                                         

The following figures are average composites of the precipitation and temperature anomalies for the years that experienced similar October upper level wind flow patterns. 

                                                                           Fig. 3. Average December through February precipitation composite.

                                                                          Fig. 4. Average December through February temperature composite.

If this method is correct, then the above figures show that this winter should be somewhat wetter than normal throughout the Mississippi Valley, Midwest, and Southwestern states.  However, mid-Atlantic states along the Appalachian Mountains and Upper New England should experience drier conditions.  The Great Lake states and Northeast should experience mild temperatures, while the west should be slightly cooler than normal.