Severe storm producing 'golf ball size hail'
UPDATE 4.50pm: ALL towns in the Northern Rivers will be affected by a wild thunderstorm, which the weather bureau said could be "very severe".
In an update to their severe thunderstorm warning BoM said the storm is "producing giant hailstones, very heavy rainfall and destructive winds".
-5cm hail reported at Urbenville at around 3:35pm
-Golf ball size hail reported at Swan Creek at around 4pm.
ORIGINAL: THE Bureau of Meteorology has warned of severe thunderstorms which could bring large hail, damaging winds and heavy rainfall that may lead to flash flooding across the Northern Rivers this evening.
Schoolies freshly arriving in Byron Bay can expect heavy winds and even hail during their first weekend partying.
Rain is expected to start later this afternoon and continue on until Sunday morning, bringing with it possible extreme weather conditions.
BoM's rain radar currently shows heavy rainfall in locations inland off the east coast.
Locations affected include Casino, Kyogle and Tabulam.
Forecasts predict up to 20mm of rainfall in some locations.
North Coast Storm Chasers forecaster Antonio Parancin said the storms would be widespread and could bring frequent lightening.
He said depending on conditions there was also a chance of a supercell.
"Places in NE NSW and SE QLD should see widespread storm activity by the late afternoon, storms should make the coast without any problems," Mr Parancin said.
He said potential "hot spots" to watch for thunderstorms were Kyogle, Casino, Lismore, Ballina, and Byron Bay but also included Coffs Harbour, Baryulgil, Tabulam, Bonalbo, Murwillumbah, Mullumbimby, Ocean Shores, Woodenbong, and parts of Queensland.
The State Emergency Service advises that people should:
* Move your car under cover or away from trees.
* Secure or put away loose items around your house, yard and balcony.
* Keep at least 8 metres away from fallen power lines or objects that may be energised, such as fences.
* Report fallen power lines to either Ausgrid on 131 388, or Endeavour Energy on 131 003 or Essential Energy on 132 080, as shown on your power bill.
* Keep clear of creeks and storm drains.
* Don't walk, ride your bike or drive through flood water.
* If you are trapped by flash flooding, seek refuge in the highest available place and ring 000 if you need rescue.
* Unplug computers and appliances.
* Avoid using the phone during the storm.
* Stay indoors away from windows, and keep children and pets indoors as well.
* For emergency help in floods and storms, ring the SES (NSW and ACT) on 132 500.