Monday, April 18, 2011

Why the increase in SEVERE WEATHER this spring?

UPDATE 4/28/2011:

Yesterday will go down as the worst tornado outbreak since the Super Outbreak in 1974 which included the Xenia tornado in Southwest Ohio.  Here is roofcam video of a mile-wide tornado that went through Tuscaloosa, Albama.

The final tornado and fatality numbers will be adjusted as the official survey the damage. Here is a look at the storm reports. The tornado reports are highlighted in red.  More than 160 IN JUST ONE DAY.

Great video of a storm chase/tornado in North Carolina from earlier in the month

Why the sudden increase in severe weather? Is it Global Climate Change?  Is it natural climate shifts?  Probably a mixture of both...The driver we will focus on is the role the Pacific Ocean plays inour weather patterns here in Northern Ohio.

The ocean temperatures go through cycles warm and cold, wet to east. This year, the ocean water temperatures are warm west and cold east near South America. This is called LA NINA. Here is an animation of the current ocean temperatures compared to normal. Notice the blue shades east.

This cooling east and warming west causes storms to develop west near Australia.

The ups and downs in the atmosphere causes the jet stream to change causing it to dive into the Great Lakes and into Ohio. Notice the "wet" green area in the Ohio Valley and the shades of red in the deep south.

Our rainfall in Northeastern Ohio has been well above normal this month.

Last year (2010), La Nina hadn't kicked in.  While we did have tornadoes in Ohio (the first graphic below showing locations and intensities last year), the country had far less tornadoes overall compared to 2008; another LA NINA YEAR!

"LA NINA" springs tend to feature greater than normal numbers of tornadoes.  The graph below shows the frequency of F4 and F5 tornadoes compared to LA NINA and EL NINO years. The LA NINA numbers are shown in the red.

Can we expect tornadic weather here in Cleveland and Northeastern Ohio this spring and summer?  Eventually yes.

Here is a loop of the storm reports for the first two weeks of June 2008, a year similar to 2011 when comparing severe weather. Notice the severe storms are further north than the recent outbreaks.

So as the temperatures rise, expect our severe weather chances to increase across Ohio into June and July

Stay Tuned!!!