In a holiday-shortened period, weekly natural gas cash prices spiked as temperatures soared and supplies waned Out West.

storage

NGI’s Weekly Spot Gas National Avg. for the Sept. 7-10 period jumped 63.0 cents to $4.995, with the Labor Day holiday on Monday compressing the trading week by a day.

Conditions were stifling across the West during the week, with triple-digit temperatures throughout Arizona, Nevada and swaths of Southern California. Wildfires added to the intensity, with dozens of uncontrolled blazes scorching land from the Northwest to Montana.

Waning supplies compounded matters.

An energy storage facility in Moss Landing, CA, was forced offline for the week after it overheated and damaged batteries, adding upward price pressure. Owner Vistra Corp. said the problem...