Motorists have been advised to use the Hume and Sturt highways as an alternative route when travelling from north of Table Top or southbound from Wagga.

Lockhart Shire council has advised that French Park, Bullenbung, Hollies and Yerong Creek Mittagong roads are closed.

There is also water over the roadways on:

Speed limits have been reduced on the highways to the west and south of Wagga following two days of severe weather that saw trees blown over, buildings damaged and cars smashed.

IN OTHER NEWS:

Lanes have been closed and the speed limit reduced to 40 kilometres per hour on the Sturt Highway around Galore with alternating start/slow traffic traffic conditions in place due to water on the road.

The speed limit on the Olympic Highway has been reduced to 60 kilometres per hour at various locations between Gerogery and Henty, also due to water being over the road.

The Bureau of Meteorology has forecast a very high chance of showers or thunderstorms, possibly severe with heavy rainfall possible in the Riverina on Friday.

"A severe thunderstorm outbreak and rainfall is forecast over the coming days with widespread areas of risk through inland NSW during ... Friday, shifting to the coast into Saturday," the BOM Flood Watch alert stated.

"This rainfall has the potential to cause riverine flooding along the Orara River in the Mid North Coast, over inland parts of NSW in the Riverina and South West Slopes and the Murray River downstream of Hume Dam at Corowa.

"Catchments conditions are average to wet following rainfall in recent weeks."

The Flood Watch status means that people living or working along rivers and streams must monitor the latest weather forecasts and warnings and be ready to move to higher ground should flooding develop.