Archive for October 2009

2006 and 2007 data updated

In a previous post, I noted that there were some significant revisions to the 2006 and 2007 SPC historical tornado archive (the source of data for this site.)  According to Gregorgy Carbin, the Warning Coordination Meteorologist at the SPC, the National Weather Service changed the way they reported latitude and longitude values in October of 2006.  The person responsible for maintaining the SPC archive at the time inadvertently continued to convert the lat/lon values from minutes/seconds to decimal degrees, even though they were now being reported by the NWS in decimal degrees.  This unnecessary conversion caused the lat/lon values to be slightly off.  When this was discovered in late 2008, he corrected the lat/lon values, while also taking the opportunity to do some additional quality control.

As of last Saturday night (10/10/2009), these changes have been incorporated into the Tornado History Project database.  Although not a comprehensive list, some key changes are listed below:

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