But he added: “Here’s the good news, the worst of the storm is expected to miss us.
“As it tracks across southern parts of the country, it’s only just going to be developing, which means the worst of the weather will track across the North Sea and unfortunately impact the low countries.”
On Wednesday, the rain band is expected to curl back, with Lincolnshire, the Peak District and the Midlands likely to experience wet conditions, Schafernaker said.
Coastal areas of Norfolk, Suffolk, Essex and Kent could also feel “near gale force” winds, he added.
In the north, frost is expected in Scotland and the Lake District.
Heavy rainfall and strong winds brought by Storm Bert over the weekend led to at least five deaths, while homes, roads and rail networks faced major disruption.
Many communities are still cleaning up after homes and businesses were inundated by floodwater.
Conall is the third ‘named’ storm of the season, after Ashley and Bert.
The storms list – first launched in 2015 – for each year generally runs from early September until late August the following year, coinciding with the beginning of autumn.