Tornado warning remains for parts of the US

The severe weather this year follows a very active year in 2011, which was the deadliest in nearly a century (REUTERS)

After two days of tornadoes across the US, a warning of severe weather is still in effect.

On Sunday the region most at risk from tornadoes is the state of Wisconsin, but the threat of thunderstorms bringing large hail and damaging winds extends all the way into the southern state of Texas.

This latest round of severe weather kicked off on Friday, when a tornado touched down in the central state of Oklahoma.

On Saturday the situation turned more serious as numerous tornadoes were reported across the four states of Oklahoma, Kansas, Nebraska and Iowa.

The storms then continued overnight, turning deadly in the early hours of Sunday.

At least five people are known to have died, including two children, after a tornado ploughed across the northwest Oklahoma town of Woodward. Reports claim that the warnings sirens failed, leaving the residents asleep and unaware of the danger.

However, after such a severe weather outbreak, the authorities are relieved that more extensive casualties have been avoided. A combination of early warnings and the network of warnings sirens is being credited. 

The area most at risk from tornadoes on Sunday 15 April

The Storm Prediction Centre is keen to point out that the threat of severe weather is not over yet. On Sunday, the weather will remain dangerous, with the majority of the tornadoes expected in Wisconsin.

The tornadoes are most likely to occur late on during the day, between 4pm and 9pm, after the sun has injected plenty of energy into the atmosphere.

The central region of the US is particularly prone to severe thunderstorms due to the interaction between the cold dry air from Canada and the warm moist air that feeds up from the Gulf of Mexico. The difference in these two different types of air is so great that the results can be explosive.

The severe weather is expected to ease on Monday, although the risk of the odd tornado can still not be ruled out.