Bright reds, oranges and yellows show tracks of where rotation was strongest as detected by NWS Doppler radars during the April 27-28, 2011 tornado outbreak. - click to enlarge
NOAA’s preliminary estimate is that there were 211 tornadoes on April 27-28, 2011.
- During the multi-day period of April 26-28, The National Weather Service (NWS) estimates there were a total of 288 tornadoes.
- NWS issued outlooks five days in advance, watches hours in advance, and tornado warnings with an average lead time of 24 minutes. NWS issued warnings for more than 90 percent of these tornadoes.
- The largest previous number of tornadoes on record in one event occurred from April 3-4, 1974, with 148 tornadoes.