NEW YORK: US natural gas futures jumped about 4% to a near one-week high on Wednesday, on forecasts for stronger US gas demand this week than previously expected and renewed worries about a possible US rail strike.

A rail strike could boost demand for gas by threatening coal supplies to power plants.

Coal fuels about 20% of US power generation. About two-thirds of the nation’s coal-fired power plants receive their coal by rail. When coal or any other fuel is not available for power generation, energy firms usually burn more gas to produce power. Gas already provides about 37% of US electricity.

Gas prices rose despite expectations gas demand would decline next month when the Cove Point liquefied natural gas (LNG) plant in Maryland shuts for a couple weeks of maintenance in October.

US gas use has already been reduced for months by the ongoing outage at the Freeport LNG export plant in Texas which has left more gas in the United States for utilities to inject into stockpiles for next winter.