Warnings are issued by local National Weather Service offices, not the Storm Prediction Center, which is a national guidance center.
On September 16, the Storm Prediction Center issues a moderate risk of severe over parts of the northern and central plains, with a large swath from the Canadian border to Oklahoma having tornado potential.
Beginning on May 29 after a Storm Prediction Center high risk severe weather forecast, 149 tornadoes were confirmed in 32 hours, killing five people.
While the Storm Prediction Center archives say that it was a single tornado, it was likely three or more tornadoes, each producing F3 to F4 damage.
Although there were some doubts on specifics, the potential significance of the outbreak was rather foreseeable, with storm chasers traveling from the Great Plains and the Storm Prediction Center issuing a high risk early on.
However, the Worcester Tornado's greatest effect on the nation was its being the principal catalyst for the Storm Prediction Center's reorganization on June 17, 1953, and subsequent implementation of a nationwide radar/storm spotter system.
The Storm Prediction Center's (SPC) Day 1 Outlook at 8 am EST, Tuesday morning, March 22 showed a slight risk for severe weather across much of the Southeast U.S.
On Saturday, March 28 at 11:30 am the Storm Prediction Center issued a Day 2 moderate risk of severe weather for southeast Minnesota, northeast Iowa, northwest Illinois and much of Wisconsin.
These watches are issued by the NWS Local Forecast Offices, not the Storm Prediction Center.
"People collect videos - classic tornado videos," says Frederick Ostby, acting director of the Weather Service's Storm Prediction Center.