Long term forecasting is a challenging science. There are two primary objectives in the attempt to solve for future outcomes:
Getting temperature, precipitation, and expectations for weather extremes right. Otherwise the demand for a prognosticator's services diminishes.
Understanding what the climate is attempting to accomplish. Unfortunately this step can be derived correctly without the outcomes in #1 being a match.
The climate playbook has many pages. The one featured today is a type of analysis which utilizes matching temperature and precipitation patterns of the present to one or more in the past. Recognizing present trends can sometimes add valuable insight into the upcoming seasons.
Summer 2009 was very distinct in terms of temperature and precipiation anomalies. The climate seemed to lock in place here in the US and Canada. Warmth failed to come north until mid to late August. The west and deep south baked in heat.
Source Link: examiner.com