Climate change may be an important contributing factor when it comes to the extreme weather that hit UK in the recent months, scientists believe.
Dame Julia Slingo said that the variable UK climate meant there was "no definitive answer" to what caused the storms.
However, she added that all the evidence suggests there is a link to climate change, the BBC reported.
More than 130 severe flood warnings - indicating a threat to life - have been issued since December. In contrast, there were only nine in the whole of 2012.
More than 5,000 properties have been flooded over this period, although the Environment Agency says investment in flood defenses over the past decade has protected a further 1.3 million properties.
Speaking ahead of the launch of a Met Office report - produced by the Centre of Ecology and Hydrology - into recent climatic events, Sling said that the UK had seen the "most exceptional period of rainfall in 248 years".
Unsettled weather at this time of year was not unexpected - but the prolonged spell of rain, as well as the intensity and height of coastal waves, was "very unusual".