(USA)fewer tornadoes than any July on record.

[Mark]

Summertime, and the twisters are missin'

July heads for a record-low tornado count.

Bob Henson | July 24, 2012 • Heat and drought are punishing much of the United States right now, but there’s actually some good weather news to report. This month is on track to produce fewer tornadoes than any July on record, and by a long shot.
 
As of July 23, this month has produced a paltry total of 14 tornado reports, according to preliminary data from NOAA’s Storm Prediction Center (SPC). While there could be more twisters before month’s end, a major outbreak doesn’t appear likely at all.
 
The chart below shows just how unusual this month has been, compared to past Julys. Graphed in blue are the final July tornado counts from the 1950s (when modern records began) to 2011. The next-most-quiet July after 2012 is 1960, which saw a total of 42 tornadoes—three times what we’ve seen thus far this month. Many Julys have produced more than 100 twisters.
 
The number of U.S. tornadoes reported each July (blue line) has gradually risen since the 1950s, with more observers and cameras watching the skies. The red line shows an estimate of how many tornadoes might have been observed if modern observing technologies and practices were in place throughout the entire period. The blue diamond at lower right shows this year’s July total: a mere 14 tornadoes, as of the 23rd of the month. (Data courtesy Harold Brooks, NOAA Storm Prediction Center; illustration by Wes Shifrin, © UCAR.)
 
The results get even more interesting when you adjust the numbers for “report inflation.” Tornado reports have gradually increased since the 1950s, especially for weak twisters. This appears to be a byproduct of the steady growth of interest in storm spotting and tornado chasing, along with the advent of inexpensive, high-quality digital photo and video tools. The attention and technology have combined to boost the reported numbers of weak tornadoes, whereas the strongest ones are being observed about as often as they were 50 or 60 years ago—a clue that it’s observing practice rather than climate change behind the trend.
 
One of the country’s most active tornado days of 2012 was April 14, when 153 twisters were reported, including this one near Cherokee, Oklahoma. Since that date, tornadic activity has run far below average. (Photo © Bob Henson.)
 
In fact, this month could end up producing fewer tornadoes than any month on record for meteorological summer (June, July, and August). Among these, the old record is 20, set in August 1957. The inflation-adjusted number for that month would be 39.

http://www2.ucar.edu/atmosnews/opinion/7547/summertime-and-twisters-are-missin

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