Some part of the United Kingdom could see two months' worth of average rainfall in just two-and-a-half days, according to forecasters. However, it is expected this number will continue to increase in the next 24 hours.
"Some stronger winds may also accompany the rainfall and may add to travelling difficulties across higher and more exposed routes".
Mr Partridge said the storm meant that some areas could see double the average amount of monthly rainfall over a few days.
Heavier rainfall also is worsening surface floods away from rivers and shorelines, in places "where we never previously expected them", as rain can not run off fast enough, said Sean Walkden, property claims manager for British insurer NFU Mutual.More news: Fulham vs. Manchester United - Football Match Report
The Met Office has issued an amber warning across parts of Yorkshire & Humber, East Midlands, East of England and North West England, in response to a forecast of heavy rain, which comes into force from 6am tomorrow (19 January) until midday Thursday (21 January).
Met Office forecaster Grahame Madge described Christoph as "quite a slow-moving system" which is bringing "a variety of weather" to the UK.
The meteorologist said: "While rain remains the main hazard in the south, further north we've got snow and ice remaining a risk".
A Met Office weather warning for heavy rain and possible flooding in the Grantham area has been upgraded from a yellow to amber alert.More news: Mercedes-Benz GLC launched at Rs 57.40 lakh
A major incident was declared in both Greater Manchester and South Yorkshire ahead of the expected heavy rainfall.
"Whilst we appreciate that everyone has been told to stay home due to the coronavirus pandemic, we want to make it clear that should members of the public need to evacuate to protect themselves due to flooding then that is the priority and you should follow your local authority's advice regarding evacuation", he said.
Katharine Smith, flood duty manager at the Environment Agency, said: "Heavy and persistent rain falling on already saturated ground with snowmelt in parts of northern, central and eastern England is expected to bring significant river and surface water flooding and could cause damage to buildings in some communities".More news: The Colts need a starting QB following Philip Rivers’ retirement