Tornado outbreaks the two largest in history – NOAA estimates more than 600 tornadoes in April, shattering record
By Jeff Masters
May 05, 2011 The largest tornado outbreak and greatest one-day total for tornadoes in history occurred during last week’s historic super tornado outbreak, said NOAA in a press release on Wednesday. They estimate 190 tornadoes touched down during the 24-hour period from 8:00 a.m. EDT April 27 to 8:00 a.m. EDT April 28 (132 tornadoes have already been confirmed, with several weeks of damage surveys still to come.) NOAA’s estimate for the number of tornadoes during the three-day April 25 – 28, 2011 Super Outbreak, is 305. This is nearly double the previous record for a multi-day tornado outbreak of 155 tornadoes, set just two weeks previously during the April 14 – 16, 2011 outbreak. There were tornado outbreaks in May 2004 (385 tornadoes) and May 2003 (401 tornadoes) that had more tornadoes, but these outbreaks occurred over an eight-day and eleven-day period, respectively, and were not due to a single storm system. Prior to April 2011, the most tornadoes in a 24-hour period, and in an outbreak lasting less than four days, was the 148 tornadoes in the Super Outbreak of April 3 – 4, 1974. … The Tuscaloosa-Birmingham tornado is likely to be the most expensive tornado of all-time, and damage from the April 25 – 28 outbreak is the most expensive tornado outbreak in history. Insured damages have been rated at $2 – $5 billion, and uninsured losses will be several billion more. The previous most expensive tornado outbreak in history was the $3.5 billion price tag, in 2005 dollars, of the April 3 – 4, 1974 Super Outbreak. … NOAA estimates there were more than 600 tornadoes during the month of April 2011, shattering previous records. The previous April tornado record was 267, set in 1974. April has averaged just 161 tornadoes over the past decade. The previous record number of tornadoes during any month was 542, set in May 2003. So far there have been an estimated 881 tornadoes in 2011. The annual tornado record is 1,817, set in 2004. May is historically the most active month for tornadoes. …
