Comes December 2020, comes a La Niña rain dump

 

This was the outlook on the NSW North Coast last Saturday evening…..

The Sydney Morning Herald, 12 December 2020:

Tens of thousands of residents in northern NSW were on high alert on Saturday evening ahead of wild weather expected to arrive late on Sunday and into Monday.

Sandbagging was under way and some residents were relocating to higher ground as the Mid North Coast and Northern Rivers regions braces for torrential rainfall and potential major flooding over the next 48 hours.

A deepening trough over the state was also expected to be accompanied by damaging winds gusting up to 90km/h and a damaging surf as waves were set to exceed five metres.

The Bureau of Meteorology has warned abnormally high tides could lead to coastal inundation and significant beach erosion north from Ballina.

It said rainfall was likely to be heavier in localities affected by severe thunderstorms. "This may lead to dangerous flash flooding,” it said.

The community of Ocean Shores, near Byron Bay, was caught without warning by flash flooding on Saturday afternoon.

An hour of pelting rain saw the streets inundated with whitewater in the coastal town.

The greatest concern in NSW looking ahead is for low lying properties that flank the Bellinger River, south of Coffs Harbour…..

The NSW SES urged people in flood-prone parts of the Bellingen region to relocate to the homes of family or friends outside the impact area….

A string of other areas across the Mid North Coast and Northern Rivers were also on flood watch on Saturday.

Catchments likely to be affected include:

Tweed and Rouse Rivers minor to moderate flooding

Brunswick River and Marshalls Creek minor flooding

Wilsons River minor to moderate flooding

Richmond River minor flooding

Orara River moderate flooding

Coffs Coast minor flooding

Nambucca River minor to moderate flooding

Hastings River minor flooding

Authorities warned high water levels due to spring tides added to the risk of flooding in low lying areas…...

From Friday 11 to Saturday 12 December, although at least 108mm of rain had fallen on the Clarence Coast and at least 125mm inland in the Grafton area, the rain had not been accompanied by destructive storms and the Clarence River system was in no danger of heavy flooding.

Evans Head on the coast which received 158.6mm of rain in the same period appeared to be weathering the rain dump reasonably well.

Early Monday morning after a day and night of continuing rain, strong winds, high seas and king tides the northern coastline of New South Wales was bruised and battered.

Main Beach in Byron Bay... gone! @9NewsSyd #NSWfloods pic.twitter.com/BWC6beCejy

— Hannah Sinclair (@hansinclair9) December 13, 2020

Gale warnings continue for waters from the Coffs Coast up to the Tweed Coast and into south-east Queensland.

The rain dump continues to sit on top of north-east NSW and the Bureau of Meteorology states that more heavy rainfall is expected, along with:

DAMAGING WINDS, with winds averaging 60-70 km/h and gusts exceeding 90 km/h are possible along the coastal fringe north from about Yamba, possibly extending south to about Crescent Head on the Mid North Coast during the day. 

DAMAGING SURF, with waves exceeding 5 metres in the surf zone can be expected, extending south to Port Macquarie during the day, possibly leading to significant beach erosion. 

ABNORMALLY HIGH TIDES are expected along the coast north from about Ballina during this morning's high tide, which may lead to localised coastal inundation. The combination of Damaging Surf and Abnormally High Tides may enhance the risk of significant beach erosion north from about Ballina. 

A Flood Watch is current for the Mid North Coast and Northern Rivers and Flood Warnings have been issued for the Tweed, Wilsons, Bellinger and Brunswick Rivers, 

See http://www.bom.gov.au/nsw/warnings/ for the latest Flood Watch/Warnings. 

Locations which may be affected include Tweed Heads, Byron Bay, Lismore, Grafton, Coffs Harbour, Port Macquarie, Sawtell and Dorrigo.

Overnight, there were over 700 SES call-outs along the Mid North and Far North Coast regions. 

As yet the NSW Road Traffic Authority is not reporting any road closures for main roads and highways.

It is being reported that by Tuesday 15 December 2020, three day totals of 300-600 ml are predicted to fall across the North Coast.