South32's (ASX:S32) Groote Eylandt Mining joint venture in Northern Territory may be impacted by adverse weather due to Tropical Cyclone Narelle, according to a Friday note by Jefferies.

Tropical Cyclone Narelle made landfall near Coen, Queensland early Friday and is forecast to make landfall in eastern Northern Territory late Saturday.

The company's 60% stake in of Groote Eylandt Mining was valued by the analysts at AU$1.32 billion and they modeled payable manganese sales from the joint venture of 1.4 wet million tonnes for the third quarter of fiscal 2026, down 4% quarter over quarter.

Severe storms such as Cyclone Narelle have the ability to impact production impact above and beyond the normal deviations, the note cautioned.

Jefferies reaffirmed its buy rating and price target of AU$5 on South32.

South32's shares fell 2% in recent Friday trade.