Hurricanes and tornadoes at below normal levels in 2009

Where are the hurricanes and tornadoes?  Both types of storms
have seen below normal level of activity in 2009.  Is climate
change responsible? 

Hurricanes and tornadoes are two of Mother Nature’s most severe weather phenomena but for this year, both have seen unusually low levels of activity. For hurricanes, tropical cyclone activity continues to be near a 30 year low and the tornado season is in the 10th percentile in terms of number of twisters.

For the third year in a row, tropical cyclone activity sits near a 30 year low and the 2009 Atlantic hurricane season is showing low levels not seen since 1997. Researchers at Florida State University said that despite what has appeared to be an active season in the Pacific, continual declines in activity are being realized across the globe.

A year ago researcher Ryan Maue documented ‘a remarkable downward trend’and that trend has continued to flirt with historic lows. Using a measurement called the Accumulated Cyclone Energy index (ACE), Maue said that “2009 as a whole is still well behind normal climatology.”

Similarly, tornado activity in the United States for 2009 is reaching unusually low levels according to statistics from NOAA’s Storm Prediction Center (SPC). As of Sunday, November 1st, 1040 tornado reports have been received this year placing it in the 10th percentile since 1954 (see chart below).

Tornadoes occur in every month on the calendar but 2009 started with far below normal numbers for the first three months of the year. As the traditional severe weather season approached during the spring, tornado numbers returned to near average but have since fallen into a decline.

Similarly, tornado deaths in 2009 are far below the average. The three year running average from 2006 to 2008 saw an average of 91 fatalities per year. Over the longer term, the United States experiences 80 per year. Thus far in 2009 only 22 deaths have been reported as a result of twisters. There was nearly a five month period from May 13th to October 9th when there were no deaths at all recorded.

What explains the lack of these types of severe weather?  Is manmade climate change responsible?  For more details, check out the related stories on the Natural Disasters Examiner site:

• Where are the hurricanes? Tropical cyclone activity at 30-year low
• Where are the tornadoes? 2009 tornado reports well below normal levels