Wichita ? The National Weather Service is giving advance warning of a possible tornado outbreak in the Great Plains on Thursday with conditions similar to a deadly day in 1974 when 39 tornadoes touched down.

Computer forecasting models for Thursday resemble those on June 8, 1974, when more than three dozen tornadoes touched down in the southern Plains and killed 22 people, including six in Emporia.

“I think this event warrants more advance warning,” said Robb Lawson, a meteorologist with the National Weather Service in Wichita.

The National Oceanic and Atmospheric Administration’s Storm Prediction Center has been warning for days of the outbreak.

Some forecasters are predicting the tornadoes could hit a corridor stretching from northern Oklahoma to central Iowa, said Mike Smith, chief executive officer of WeatherData Inc., a subsidiary of AccuWeather.

“Certainly Wichita, Topeka, Emporia, Salina, Chanute … essentially the eastern half of Kansas should really be paying attention on Thursday,” Smith said.

Smith said temperature and humidity patterns for Thursday are similar to the 1974 outbreak, with a wave of energy in the upper atmosphere projected to be in exactly the same position.

With so much humidity in place, storms on Thursday could form and quickly become strong, forecasters said.

“If you take April dynamics and June thermodynamics, you have a potentially disastrous combination,” Smith said.