Joplin, Missouri, the scene of the deadliest tornado in our nation’s history, with winds exceeding 190 mph, left a path of destruction ¾ of a mile wide and 4 miles long through the heart of the city. In the aftermath, we have seen America’s traditional shelters of protection, hospitals and schools, destroyed in Joplin. With entire communities mourning the loss of 116 lives thus far and miles of seeming unearthly destruction, America is unnerved. Our thoughts and prayers are with the families of Joplin, and community now involved in their rescue under extreme conditions.
Joplin is the most recent in a year of extraordinary weather that has recorded a historic flood height on the Mississippi, and a record super tornado outbreak. Patterns seem heightened causing concern for the upcoming June 1st start of the hurricane season. With May 22nd beginning National Hurricane Preparedness Week, Gerry Bell, forecaster at NOAA’s Climate Prediction Center, believes this hurricane season will compare to our most active. Does this deadly 2011 tornado season portend a major hurricane landfall in a season predicted to be above normal by Colorado State University?
Unfortunately, this year’s tornados do suggest the Atlantic and Gulf coasts will see their share of destruction in 2011. First, hurricane patterns do loosely follow tornados. While both form in warm, damp air when winds blow into each other from opposite directions, the localized drivers are quite different. However, seasonal, annual and global patterns correlate. In years during or immediately following peak tornado activity, major landfall hurricanes have occurred. Hurricane Betsy landed in 1965, Agnes in 1972, Andrew in 1992, Charley in 2004, Katrina in 2005, and Gustav and Ike in 2008, all correlating to peak tornadic activity. This pattern does not bode well for 2011, with Colorado State University predicting probability of hurricane landfall in 2011 at 72%.
Second, both tornadic and hurricane activity is escalating. In the ‘50s we averaged 400 tornados per year, in the ‘70s 800 per year, in the ‘90s 1,200. In 2004, the same year that Florida was ravaged by four hurricanes, we had over 1,800 tornados. Between the ‘50s and ‘80s, with the exception of 1969, the year of Camille, America had milder patterns of hurricanes. However, since then, hurricanes have been much more active, deadly, and costly. 2010 was actually a year of peak hurricane activity with an incredible 12 hurricanes that missed landfall due in part to La Nina.
Which brings us to our third forewarning, the expected ending of La Nina prior to this hurricane season. During years of La Nina, America has been blessed with mild hurricane landfalls, but in seasons immediately after La Nina, America has experienced major destruction including Betsy in 1965, Agnes in 1972, Hugo in 1989, and Ike and Gustav in 2008.
Finally, I would be remiss in not at least mentioning increasing sunspot activity. 2011’s active weather season follows several years of relative calm corresponding to unusually low sunspot activity, but the 11 year sunspot cycle has begun again. Scientists believe that increased sunspot activity causes the ocean’s surface to warm across the subtropical Pacific, leading to more evaporation and water vapor. The trade winds then carry this vapor to the rainy areas of the western tropical Pacific, fueling heavier rains and reinforcing active weather patterns.
Hurricanes Betsy and Hugo both occurred at the start of sunspot activity such as we are now experiencing. Sunspots along with other significantly correlating data points suggest an overactive hurricane season with the potential for major landfall in 2011. 2011, already a difficult year for America, may well be remembered for its major emergencies and America’s enduring response. God Speed.