In total, 56 severe weather watches (2011 watches, 199 256; two watches were omitted in error) were issued by the Storm Prediction Center (SPC) over those four days in the outbreak area, including 41 tornado watches (10 of which were PDS watches) and 15 severe thunderstorm watches.
It does so primarily by issuing convective outlooks, severe thunderstorm watches, tornado watches, and mesoscale discussions.
A total of fifteen watches were issued by the SPC during the outbreak, including thirteen tornado watches (two of which were PDS watches) and two severe thunderstorm watches.
"When we issue a severe storm watch, it means precautions need to be taken," Mr. Imy said.
The National Weather Service had established a severe thunderstorm watch before the storm struck at 7 52 p.m., and minutes later issued a tornado warning for Monmouth County based on a sighting by a trained weather observer who reported to emergency officials.
May 21 , 20134.51pm BST The threat of heavy weather in Moore today has not dissipated; a severe thunderstorm watch has been issued today through 7pm local time for central and southern Oklahoma, including the Oklahoma City area.
In a building not far from the stage, they said that all evening a contingent of officials — including a meteorologist — had been monitoring the weather, which had, since before 6 p.m., included a severe thunderstorm watch from the National Weather Service.
David Imy, a meteorologist with the National Weather Service, said a severe thunderstorm watch for all of Indiana was issued just before 6 p.m. Saturday, almost three hours before the winds struck the concert venue.
The accident, which occurred hours after a severe thunderstorm watch was issued, resulted in the deaths of seven people and injuries to dozens more, and video of the frightening scene spread rapidly across the Internet.
Along with checking for any evidence of structural problems with the stage setup, investigators will also be looking into whether fair officials acted swiftly enough or paid appropriate heed to a severe thunderstorm watch that was issued nearly three hours before the scheduled concert.
