Thunder rattles Newcastle, lightning splits sky as severe storm hits

The Bureau of Meteorology (BOM) issued an alert for parts of the Hunter just before 4pm on February 14.

The BOM warned damaging winds, large hailstones and heavy rainfall could hit Newcastle when severe thunderstorms developed in the Hunter.

Fire and Rescue NSW crews were deployed to storm-hit areas across the region in the aftermath of the storm.

A spokesperson said there was a "significant amount of resources" that were out on Wednesday evening helping with the clean-up effort after wild weather ripped through.

NSW SES crews had 19 calls for help across Newcastle, Lake Macquarie and the Hunter Valley, and at about 5.20pm seven were outstanding in Newcastle.

Hunter and Central Coast northern zone superintendent deputy commander Ian Robertson said he expected more jobs to come in as people returned home this evening, but said they were likely to be anything severe.

"The biggest risk would have been the potential for flash flooding with the heaviness that came down, but we've had no requests for flood rescues at this stage," he said.

"I would expect as people come home from work we might have more call outs for leaky gutters or broken skylights but I don't think it will be anything too dramatic."

There was some waist-deep flooding reported with blocked drains at Gordon Avenue, Hamilton, but Mr Robinson said he didn't expect a great deal of activity tonight.

BOM data reveals the weather station at Nobbys in Newcastle recorded 11.8mm of rain in less than 10 minutes after 4.30pm.

The temperature dropped from 32 degrees earlier in the afternoon to 21 by 4.45pm, and wind gusts of up to 87 kilometres per hour were clocked.

A southerly change which moved up into the Hunter district this afternoon triggered thunderstorms in a humid and unstable environment, according to the BOM.

Locals reported flash flooding in areas like Wickham, where water was seen pooled in gutters and lapping at the bottom of cars.

More than 1200 customers were plunged into darkness when the electricity went off during the storm in the Cardiff area.

Ausgrid said the power outage began about 4pm and should be restored by about 6.30pm.

Affected areas include Cardiff, Cardiff Heights, Garden Suburb, New Lambton Heights, Macquarie Hills, Edgeworth, Kotara and Adamstown.

Another 1179 were without power in the Mount Hutton, Charlestown and Warners Bay areas after the storm, starting from about 4.30pm and with an estimated restoration time of about 7pm.

Locations which were set to be impacted included Newcastle, Cessnock, Glen Davis, Lithgow, Capertee and Bilpin.

In Newcastle, thunder could be heard and lightning was seen splitting the sky on Wednesday about 4pm.

The SES advised that people should: