Another attack by the 7th Armoured Division and other offensive operations were abandoned when a severe storm descended on the English Channel on 19 June. The storm lasted for three days and further delayed the Allied build-up. Most of the convoys of landing craft and ships already at sea were driven back to ports in Britain; towed barges and other loads (including of floating roadways for the Mulberry harbours) were lost and 800 craft were left stranded on Normandy beaches until the spring tides in July.