A severe thunderstorm warning has this afternoon been issued for the Illawarra and parts of the South Coast.The Bureau of Meteorology has predicted heavy storms would strike a large section of the state later today, with the Blue Mountains and Hawkesbury areas to be worst hit.It comes just days after sections of the Illawarra were swallowed by flash flooding resulting from severe storms.On Thursday night, a localised deluge caused flooding in Wollongong’s north.The following night a huge storm left sections of Warrawong and Berkeley under water, causing headaches for motorists attempting to navigate waterlogged streets.For help in storms and floods call the State Emergency Service on 132 500.