US natural gas futures plunged over 10% on Monday to a seven-week low on forecasts for less demand over the next two weeks than previously expected due to a decline in liquefied natural gas (LNG) exports.

Gas flows to LNG export plants dropped because of planned maintenance at Dominion Energy Inc's Cove Point in Maryland, the continued outage at Cameron in Louisiana and as some ships steer clear of Tropical Storm Beta, which is expected to lash the Texas and Louisiana coasts this week.

Front-month gas futures fell 21.3 cents, or 10.4%, to settle at $1.835 per million British thermal units (mmBtu), their biggest one-day percentage drop since January 2019 to their lowest close since July 31.

That drop puts the front-month down 33% since hitting an eight-month high of $2.743 per mmBtu on Aug. 28 and boosted the premium of November futures over October to a record high of 89 cents.

Despite the recent drop in the front-month, gas speculators last week increased their net long positions on the New York Mercantile and Intercontinental Exchanges for the seventh time in eight weeks to their highest since May 2017 on expectations energy demand will rise as the economy rebounds once state governments lift more coronavirus-linked lockdowns.

Those added long positions came despite expectations stockpiles will hit record highs by the end of October, which should remove lingering concerns about price spikes and gas shortages this winter.

Data provider Refinitiv said the amount of gas flowing to US LNG export plants was on track to slide to a two-week low of 5.2 bcfd on Monday from a four-month high of 7.9 bcfd last week.

LNG feedgas has averaged 5.6 bcfd so far in September. That was the most in a month since May as global gas prices rise, making US gas more attractive.