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Flash Flood Threat Persists Across Southwest; Heat Threat in Several Regions

Monsoon conditions will exist over the Southwest through Tuesday, resulting in localized areas of flash flooding from California into the Central and Southern Rockies. Hot and humid conditions will impacts several regions through early week. Excessive Heat Warnings are in effect for the Intermountain West and Northern Plains with Heat Advisories from the southern Plains into MS River Valley. Read More >

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Severe Weather Climatology

Significant Tornadoes in the United States (1950-2002)

Pictured above is a map of significant tornado (F2 or stronger on the Fujita Scale) frequency from 1950 to 2002. Based on this map, it is apparent that Central Oklahoma has been the most active place in the United States for significant tornadoes over the past half century. The maximum gridpoint, shown in blue on the map, is actually centered over Del City, Oklahoma -- in the Oklahoma City metro area. Click here for a similar map of hail greater than 2 inches in diameter.

Interesting Facts

  • The primary severe weather season for the NWS Norman County Warning Area runs from March through June. This is when 83% of Oklahoma tornadoes occur, with a peak of 38% in the month of May. Click here for a tornado frequency graph for the Oklahoma City area, courtest of NSSL Severe Weather Climatology.

  • Oklahoma averages 53 tornadoes, 15 significant tornadoes, and 1 violent tornado per year. The state also averages 20 days per year with a tornado. Based on 50-year averages.

  • Nine violent tornadoes (eight F4 and one F5) have impacted the Oklahoma City Metropolitan Area.

  • The Oklahoma City area has been struck by a tornado twice in one day a total of 18 times.

  • In May of 2005, there were no tornadoes reported in Oklahoma. This was the only time this has occurred in the month of May dating back to 1950 in Oklahoma.

  • The most number of tornadoes in one year in Oklahoma was 145 in 1999.

  • The least number of tornadoes in one year in Oklahoma was 16 in 2014.