Late winter salt storage constraints that helped steepen U.S. natural gas forward curves to near record levels have started to ease with the onset of the injection season, likely providing a tailwind to prompt prices.

NGI December forward prices for benchmark Henry Hub stood at a $1.693/MMBtu premium to May at the start of April, with May priced at $1.769 and December at $3.462, NGI’s Forward Look data show. That’s the steepest premium for May-December at the end of the injection season over the past 10 years. 

The factors driving this year’s contango, where forward prices are at a higher premium than prompt, are well established. The warmest winter on record stalled heating demand, swelling Lower 48 gas inventories to crash cash prices to 25-year lows. Meanwhile, the...