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.
A perusing of temperature and precipation anomalies in past years yielded a very surprising result. Summer 1977 experienced a similar pattern. In addition the West and East Atlantic ridge indexes were stuck in negative, leading to very quiet tropical seasons. When the upper levels of the tropical Atlantic are cooler then westerly winds prevent storms from organizing and often snuff them out whether the ocean is warm enough or not.
It is impossible to find a perfect match but you can be the judge regarding whether this past summer is similar enough to 1977 to indicate the likelihood of the same overall weather pattern. I also like the idea of 1977 following a quiet solar minimum amidst a century of rising activity. Today's quiet sun has reached century class in terms of spotless days and solar cycle length. Therefore I expect similarities to the outcomes below. We must respect the fact that cliamte data is seriously lacking for deep solar minimums like today (except that we know it that in general winters are more severe).
It is important to be aware that a large scale severe winter is a real possibility this year. This is not yet my prediction. Something like the 1977-78 winter season appears to be what the climate wants to ultimately accomplish. Will our slide downward from warm NC winters of 2006-07, 07-08 continue or will overall temperatures crash and our region become greatly affected by prolonged cold and frozen precipitation?
There is good reason to be suspicious that the upcoming season is the one that will bring back the glory days of the late 1970's to NC. My next article will examine some reasons why the upcoming season might simply be a step down from 2008-09 instead of a crash,
Source Link: examiner.com