It is the highest form of flood alert and means severe flooding and danger to life.
The high tide at Lowestoft is due at 9.45am and Harwich is due at 12.30pm.
Properties are at risk around the Mere in Thorpeness, Aldeburgh and surrounding marshland, including the A1094 at Aldeburgh.
Flooding is expected for South Quay, North Quay, Hall Quay and the Vauxhall bridge areas. In Newtown roads between the river and Beatty Road and North Denes Road including the Caister Road area and Bure Park are at risk.
Flooding is expected for properties in South Denes Road,Southgate Road, South Quay, Middle Roads East and West, Fish Wharf, Sutton Road, Barrack Road, Exmouth Road, Ordnance Road, Newcastle Road, Admilitary Road and roads between Queens Road and Alma Road.
Flooding is expected for Great Yarmouth Railway Station, Vauxhall Holiday Park, Acle New Road, Runham Road, School Road, North River Road, Bridge Road and the Euro Centre Industrial Estate.
Properties are at risk in Gorleston including Pier Gardens, Beach Road, Pier Road, Pavilion Road, Quay Road, Pier Walk, Limmer Road, Bells Marsh Road, Pier Plain, Riverside Road, Dock Tavern Lane, Baker Street and Blackwall Reach.
Cobholm Island is at risk and all roads in Southtown including the Southtown Common area down to Burgh Road and Harfreys Industrial Estate.
Properties are at risk at Bawdsey Quay and in front of the flood defences at Felixstowe Ferry.
Properties behind the sea wall at Felixstowe Ferry and Felixstowe Ferry Golf Club. Newbourne, Ramsholt, farmland, marshes and isolated properties on the Deben Estuary are also at risk.
[Isolated riverside properties on the Deben Estuary](http://Isolated riverside properties on the Deben Estuary )
Properties around Martlesham Bridge including those on Bealings Road, School Lane and Sandy Lane. Riverside areas around Waldringfield and Methersgate Quay
Areas at risk include Lowestoft Denes caravan park, industrial estate and docks area.
Properties are at risk in Denmark Road and Commercial Road in Lowestoft, including the railway station and the railway line.
Properties are at risk at Broadland Holiday Village and caravan parks, Nicholas Everitt park and adjacent areas.
[Snape, Iken and surrounding marshland](http://Snape, Iken and surrounding marshland)
Properties are at risk at Snape Maltings, Priory Road and The Street at Snape and surrounding marshland.
Properties are at risk around the Southwold Harbour area, Ferry road, the bottoms of Queens Road and Constitution Hill, North Road, the bottom of Pier Avenue and Mights Road in Southwold. Bridge Road and Hillside Road in Reydon.
Industrial areas around Cliff Quay are at risk.
The forecast high water is due at Clacton at 1pm on 13 January 2017.
The warning is for roads around the Martello Tower in Clacton on Sea. Including Hastings Avenue, Selsey Avenue and Portsmouth Road. Clacton Golf Course, Jaywick, Sea Wick and Lee over Sands.
The forecast tide level is 3.58 m.
Flooding is expected for marshland around Mersea Island, The Strood.
Waterside properties in West Mersea are at risk including those on Shears Crescent, Coast Road, Seaview holiday park and Waldegraves holiday park.
A Severe Flood Warning has been issued by the Environment Agency for Tidal River Stour at Mistley, including the Quay and The Walls.
The forecast high water is due at Harwich at 12:45pm on 13 January 2017.
The Walls, Mistley Place Park and waterside properties at Mistley Quay.
The forecast tide level is 3.50 m
A number of flood warnings are also in force around the East coast.
The Environment Agency has also issued a series of flood alerts along the East coast with high winds and a storm surge raising tidal levels.