Climate of Our Future

Michelle Dyer - Florida Weather Info Lady

Last week I began an investigation into whether or not there has been a shift in the nation’s tornado activity from the Great Plains to the Southeast US. We looked at how global warming would, and already is, impacting the “Jet Stream”. The examination looked at how the heating up of the atmosphere would push the global jet stream pattern away from areas that normally see it, thus lowering the presence of tornado activity in and around the state of Oklahoma.

I had also stated that tornado activity would not decrease, but that it would shift from one location to another. My prediction is that the Southeast US will see more of this activity in the winter months, thus placing this region of the country in greater danger for severe weather threats that haven’t been seen prior to now. I’d like to call this the “Permanent El Nino Effect”.

Florida’s Current Climate

Florida is famous for its pleasant temperatures, warm-temperate to subtropical climate and occasional winter freezes. There’s a distinct wet season in the summer and a dry season in the winter. Rainfall totals can vary widely from year to year.

Florida’s annual rainfall is primarily brought on by extratropical storms in the winter, summertime afternoon thunderstorms and tropical storms in the summer and fall. Tropical storms strike Florida on average every 1 to 2 years. Hurricane frequency varies by decade and is strongly influenced by the El Nino/La Nina cycle.

Changes in Florida’s Temperatures

The average state temperatures have varied substantially over the past century. This includes a warming trend that has been taking place since the late 1960s. There’s been a noticeable 3 to 10 F degrees elevation in winter lows and a 3 to 7 F degrees rise in summer. Most notably, there has been a northerly lift in the freeze line. To learn more about this, as well as to view references, please visit http://www.ucsusa.org/gulf/gcstateflo_cli.html

What’s The Permanent El Nino Effect?

This past winter and spring, the Southeast United States had been impacted by a weather phenomenon known as El Nino. The term “(El Nino Southern Oscillation)is a global coupled ocean-atmosphere phenomenon. The Pacific ocean signatures, El Nino and La Nina, are important temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. The name El Nino originates from the Spanish word for “the little boy”, which is a reference to the Christ child. This is due to the phenomenon’s usual occurrence around Christmas time. To learn more about this phenomenon, please visit http://en.wikipedia.org/wiki/El_Ni%C3%B1o.

Why does this matter? Well, when one considers the impacts El Nino has had over the years, then it’s not hard to understand what kind of permanent effects such warming of our world’s oceans, on an on going scale, will have on local climates. For example, “the average winter rainfall in Florida has increased while average summer rainfall has decreased. More frequent intense rainfall events are projected, with longer dry periods in between.” For as long as I’ve lived in Florida, that has always been noted as an El Nino weather pattern. To read up on how Florida’s climate is changing, please visit http://www.ucsusa.org/gulf/gcstateflo_cli.html.

Next week we will look deeper into the El Nino/La Nina phenomenon and what it means in terms of climate change. The past El Nino weather related events will be compared to the expected climate change projections that have been layed out in previous writings.