The level of concern over flooding caused by a storm surge, downpours and large waves crashing into the coast has been upgraded to severe, the highest level.
Warning of a 'danger to life' it applies to the North Cornwall coast at Wadebridge including Harbour Road, The Platt, Eddystone Road, Southern Way, Jubilee Road, Egloshayle and Sladesbridge, Bude including The Strand and The Crescent and for Lands End to Plymouth excluding Truro and Plymouth Barbican.
An Environment agency spokesman said: "Flooding is expected over the high tides on Saturday morning and afternoon, Sunday morning and Monday morning. Times of high tide will vary along the coast. Conditions will usually apply two to four hours either side of high tide.
"A severe flood warning is in force for Saturday mornings tide and a flood warning will be in force until Monday morning.
"On Saturday morning wind is forecast to be West South Westerly force 8, with waves over 6m, and the surge around 300mm. Overtopping of defences is expected.
"Impacts are likely to be similar to the coastal flooding in early January. The recent storms have caused damage at coastal locations.
There may be an increased risk at Stonehouse, Plympton, Lamorna, Penzance, Porthleven, Mullion, Pentewan, Seaton and Kingsand. Coastal areas will be extremely dangerous, the public are advised to avoid these areas. We will continue to monitor the situation and provide regular updates."
"Recent storms have caused damage at coastal locations. There may be an increased risk of flooding at Bude, Newquay, Perranporth, Portreath and St Ives."
Weather update: Further heavy rain and strong winds, turning colder.
The worst of the rain will ease away by around sunset but showers will quickly follow on. The chance of some hail mixed in with the heavier showers.
A more organised band of showers is possible from mid-evening time, spreading east. The worst of the showers should then clear by around midnight leaving the rest of the night with clear spells and scattered showers.
Some of these showers will fall as hail and to high ground sleet or even wet snow (snow generally falling on ground above about 250 metres) although any snow is not expected to settle.
Turning progressively colder with RSTs falling close to or below zero bringing a high risk of ice along with hoar frost. Towards the end of the night and in to Saturday morning, it will become very windy.
There will be further showers with the chance of some longer spells of rain from mid-morning.