The storms aren't over yet, more on the way
Update 5.39pm: MORE storms are heading our way from the north west, with Mullumbimby and Byron Bay in the firing line.
Areas around Burringbar have dark clouds gathering.
Update, 4.25pm: AN OFFICIAL severe thunderstorm warning has been issued for the Northern Rivers.
The Bureau of Meteorology said Severe thunderstorms are likely to produce giant hailstones, heavy rainfall that may lead to flash flooding and damaging winds over the next several hours and may affect areas around Lismore and Grafton.
Hail has been reported at Casino, Doubtful Creek and Tuncester.
"A low pressure system is tracking eastwards across New South Wales triggering thunderstorm activity through parts of New South Wales," the BoM warning states.
"Severe thunderstorms are likely to produce large hailstones and damaging winds over the next several hours ... 4cm hail has been observed from a thunderstorm at Coopernook, on the Mid North Coast."
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
- 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.
The next warning is due to be issued by 6.30 pm.
Update, 2.30pm: BUREAU of Meteorology forecaster, Simon Louis, said the Northern Rivers was in for some wild and windy weather this afternoon and this evening.
There is no official severe weather warning at this stage.
But Mr Louis said "all the ingredients (are) there for some pretty severe storms".
"It's likely they will develop on the ranges to the west over the next few hours and move across to the coast later this afternoon and into the evening," he said.
Mr Louis said people should be aware a complicated low system over the state is the likely storm trigger.
"On this part of the state you think there's a pretty good chance of large hail and damaging wind gusts," he said.
"It's often a bit hit or miss on who gets affected as it not a widespread rainband."
Mr Louis said the severe storms are likely to head out over the Tasman early Friday morning.
"There may be a bit of rain early tomorrow morning and the day should clear up pretty well," he said.
Update, 12.30pm: FORECASTER from North Coast Storm Chasers, Antonio Parancin, says conditions are prime for supercells.
He said the weather was looking "volatile with thunderstorms likely to become severe and perhaps possibly even spawn a supercell".
"First of all a supercell requires rotation in the atmosphere in order for the storm cell itself to begin rotating," Mr Parancin said.
"This is very present with winds at the surface coming in from the north/north-northeast then as we go up in the atmosphere these winds start coming in from the north-northwest/northwest and west-northwest, which creates 'spin' or 'rotation'.
"Now what's important to remember here is that if we see even the slightest hints of a northeast wind coming in at any time at the surface then there is a increased likelihood of a supercell or even supercells forming.
"Not only that but thanks to a very cool atmosphere above we might then also see a second round of strong and even severe thunderstorms into tonight and into the morning."
Mr Parancin said he was heading out storm chasing from 1pm, and expected the situation to develop quickly.
He said supercells involved large to very large hailstones, damaging or even destructive wind gusts, very frequent and close dangerous lightning, brief periods of intense rainfall.
Update, Thursday 10am: LISMORE State Emergency Service are advising residents to secure loose items in their garden, put their car under cover and avoid unnecessary travel as a storm supercell is predicted to impact across the Northern Rivers today.
SES communications officer Janet Pettit said wild weather was on the way and everyone needs to take extra care.
"We can expect heavy bursts of rain, hail, thunder, lightning and severe winds, so if you can avoid travelling and stay at work or at home do so," she said.
"And take extra care while driving."
Ms Pettit said people should check their property and remove items which could be flung about in a storm.
"If you have time and it is safe to do so, clear your gutters," she said.
"Secure any loose items in the garden, tie down trampolines and keep pets inside."
Ms Pettit said anyone requiring storm assistance can call 132 500.
"If you are in a life threatening situation always care triple zero (000), she said.
Update, Thursday 7am: STORMS are highly likely to hit the Northern Rivers today, as weather experts firm up their forecasts.
The Bureau of Meteorology says Lismore will reach 31 degrees today, with a "thunderstorm likely, possibly severe with damaging winds during the afternoon and early evening".
Higgins Storm Chasing yesterday predicted damaging supercells for the North Coast and again confirmed that severe storms were possible.
"Severe thunderstorms are likely to develop … large hail over 2cm in diameter and damaging winds over 90km/h a high risk," they posted on their Facebook page.
"Dangerous thunderstorms in the form of isolated supercells are also possible.
"Isolated giant hail over 5cm in diameter and destructive winds over 125km/h are possible."
Original story, Wednesday 11am: PARTS of Northern NSW could be in for some severe weather tomorrow, according to storm forecasters Higgins Storm Chasing.
The forecasters have warned their 670,000 Facebook followers of the potential for "dangerous storms (supercells)", with large hail, damaging to destructive winds, heavy rain and frequent lightning.
"Now this is a very tricky forecast to get high detailed accuracy on ATM due to model data variables," the Higgins team posted.
"One thing is for sure there will be storms around and some will be severe.
"They will start inland just after lunch time and race towards the coast very fast due to high speed steering winds.
"The biggest current threat is damaging winds over 90km/h, possibly destructive over 125km/h based on a conservative outlook for lack of low level moisture.
"There is an issue with exact forecast location variables of where the storms will be more likely to develop - south of Brisbane or north of Brisbane - so we are obligated to blanket warn a large area until model data comes to higher agreement.
"If low level moisture increases (which some data suggests) then we will have an even higher more widespread threat level."