Crozet Weather Almanac: May 2013


By Heidi Sonen & Roscoe Shaw 

May 2013 Weather Data
May 2013 Weather Data

May was a terrible month for tornadoes, with several major tragedies. The worst damage was in Oklahoma and the El Reno tornado was the widest storm track ever measured at 2.6 miles across, with winds of 200 mph. The storm completely destroyed 600 acres of land per minute!

The United States is far and away the most tornado-prone place on earth, and the closer you get to Oklahoma City, the greater the threat. Although tornadoes occur in many countries, nothing compares to “tornado ally” in the central U.S. All the ingredients come together here… cold, dry Canadian air, warm moist Gulf of Mexico air, and flat ground that doesn’t disturb rotation.

The last factor, “flat ground,” is what saves us here in Virginia. Strong tornadoes almost always move from the southwest or west. The Blue Ridge Mountains dramatically help to break up the rotation and the tornado frequency map clearly shows the protective effects of the entire Appalachian chain.

We aren’t totally safe, though. I was once at Boar’s Head while Heidi was in Crozet and a weak tornado passed between us while we talked about it on cell phones.

After the storms, the usual articles and blogs blaming global warming popped up. However, the science doesn’t support these claims. The year 2012 had the lowest tornado activity ever and 2013 was also unusually quiet until mid May. Most climate change science suggests that tornado activity is likely to be steady or actually decrease in a warmer world.

May Recap

May was cool and rainy, which made the month a lawn mowing nightmare. Our weather turned colder than normal in mid-February and the cool stretch has continued, giving us a very late spring. May was a full three degrees below normal.

Area Rainfall Totals:

  • Crozet  5.05”
  • Greenwood 4.27”
  • CHO Airport 4.35”
  • Waynesboro 6.22”
  • Univ. of VA 4.72”
  • Nellysford 3.82”