Adds latest prices

By Scott DiSavino

Oct 28 (Reuters) -U.S. natural gas futures plungedabout 10% on Monday to a one-week low,on forecasts for mild weather through at least mid-November, less demand next week than previously expected and an increase in output in recent days.

Another factor weighing on gas prices was a 6% drop in oil futures on Monday after a limited Israeli attack on Iran over the weekend. O/R

On its second to last day as the front-month, gas futures NGc1 for November delivery on the New York Mercantile Exchange fell 25.1 cents, or 9.8%, to settle at $2.309 per million British thermal units (mmBtu), their lowest close since Oct. 18.

That was the biggest daily percentage loss since the contract lost about 17% on Jan. 30.

Futuresfor December NGZ24, which will soon be the front-month, were down about 23 cents to $2.86 per mmBtu.

With mild weather squeezingdemand and output rising, analysts projected utilities likely injected more gas into storage than normal last week fora second week in a row for the first time since October 2023. There was about 5% more gas in storage than normal for this time of year. EIA/GAS NGAS/POLL

Prior to last week, injections had been smaller than usual for 14 weeks in a row because many producers have reduced drilling activities so far this year after average spot monthly prices at the U.S. Henry Hub NG-W-HH-SNL benchmark in Louisiana fell to a 32-year low in March. Prices have remained relatively low since then.

Looking ahead, the market is showing signs of giving up on thoughts that extreme cold could cause prices to spike this winter with futures for March 2025 trading at a record low premium over April 2025 NGH25-J25 of just 5 cents per mmBtu.

March is the last month of the winter storage withdrawal season and April is the first month of the summer storage injection season. Since gas is primarily a winter heating fuel, traders have said summer prices should not trade above winter.

The industry calls the March-April spread the "widow maker" because rapid price moves on changing weather forecasts have forced some speculators out of business, including the Amaranth hedge fund, which lost more than $6 billion in 2006.

SUPPLY AND DEMAND

Financial group LSEG said average gas output in the Lower 48 U.S. states slipped to 101.6 billion cubic feet per day (bcfd) so far in October, down from 101.8 bcfd in September. That compares with a record 105.5 bcfd in December 2023.

But on a daily basis, output was up about 1.6 bcfd over the past four days to a preliminary eight-week high of 102.8 bcfd on Sunday.

With so many firms curtailing drilling activities so far this year, analysts projected average output in calendar 2024 will decline for the first time since 2020 when the COVID-19 pandemic cut demand for the fuel.

Looking forward, however, analysts projected producers would boost output to meet rising liquefied natural gas (LNG) export demand with two new export plants - Venture Global LNG's Plaquemines in Louisiana and Cheniere Energy's LNG.N Corpus Christi stage 3 expansion in Texas - expected to enter service later this year.

The Venture Bayou, an LNG tanker, anchored near the mouth of the Mississippi River by early Monday on its way to Plaquemines, data from LSEG showed.

LSEG forecast average gas demand in the Lower 48, including exports, would rise from 99.1 bcfd this week to 101.5 bcfd next week. The forecast for next week was lower than LSEG's outlook on Friday.

Reporting by Scott DiSavino; editing by David Evans and David Gregorio

For gas data on the LSEG terminal, type ENERGY in the search bar and then go to the GAS drop down and the NORTH AMERICA drop down.

For Interactive Map, type 'Interactive Map' in the box at upper left of the LSEG terminal

For graphics on Baker Hughes rig counts, see: http://graphics.thomsonreuters.com/15/rigcount/index.html

For next-day SNL U.S. gas prices, see: 0#SNL-NG

For next-day SNL U.S. power prices, see: 0#SNL-PWR

For U.S. natgas price and storage polls, see: NGAS/POLL

For U.S. nuclear power outages, see: NUKE/

For U.S. Northwest hydro power report, see: NWRFC

For U.S./Canada natural gas rig count vs Henry Hub futures price, see: http://tmsnrt.rs/2eT9k44

For the U.S. natural gas speed guide, see: USGAS

For the U.S. power speed guide, see: USPOWER

To determine CFTC managed money net position add (NYMEX Henry Hub options and futures combined 3023651MNET) plus (ICE Henry Hub options and futures combined 3023391MNET divided by four) plus (NYMEX Henry Hub swaps options and futures combined 303565BMNET divided by four) plus (NYMEX Henry Hub penultimate gas swaps 303565CMNET divided by four)

NYMEX Henry Hub options and futures combined 0#3CFTC023651

NYMEX Henry Hub futures only 0#1CFTC023651

ICE Henry Hub options and futures combined 0#3CFTC023391

NYMEX Henry Hub swaps options and futures combined 0#3CFTC03565B

NYMEX Henry Hub Penultimate gas swaps 0#3CFTC03565C