The amber warning, with flooding and disruption likely in places, covers north Lancashire and Cumbria from tonight and until tomorrow evening when the weather is expected to become more showery.
The Met Office has warned that the heavy rain could lead to spray and difficult driving conditions.
National Highways is advising anyone using motorways and major A roads in the north of the region to take extra precautions in heavy rain such as cutting their speed, driving with dipped headlights and keeping their distance from other vehicles, leaving extra room for braking.
National Highways says traffic officers and maintenance teams at depots across Lancashire and Cumbria will be on standby tonight and tomorrow to respond to any rain-related incidents.
M6 reopens after vehicle transporting sheep overturns following crash between Preston and Lancaster
Lytham St Annes care home boss appears in court after death of residents
The Old Vicarage Care Home: special measures status for Lancashire care home where resident was left lying on floor after falling out of bed
Preston Brick Veil Mosque inquiry closes as debate rages over whether the place of worship should be permitted
Morecambe 'neighbour from hell' back in court after breaching order
This evening the Met Office updated its advice warning there could be flooding in some areas during the next 24-36 hours and advised:" Much of Cumbria will see around a month's worth of rain by the end of Thursday with as much as 250 mm over the fells." Yellow and amber weather warnings were applied to parts of Cumbria.
For full advice, including precautions for driving in heavy rain, see here .
Met Office updates will be available at www.metoffice.gov.uk see here .
Live traffic information is available at www.trafficengland.com or here with regular updates from National Highways’ regional Twitter feed at @HighwaysNWEST.
Drivers are also being advised to pay attention to safety messages on overhead electronic signs, to listen for radio updates, and to check weather and traffic conditions before setting out on journeys.
* The Lancashire Post is more reliant than ever on you taking out a digital subscription to support our journalism. For unlimited access to Lancashire news and information online, you can subscribe here