Adds closing price

By Rahul Paswan

Sept 18 (Reuters) -U.S. natural gas futures fell more than 1% on Wednesday in a volatile trading, on fewerwarmer-than-normal weather forecasts than previously expected, even as production was slow to ramp up to match demandafter Hurricane Francine.

Front-month gas futures NGc1 for October delivery on the New York Mercantile Exchange fell 4.0 cents or 1.7% to settle at $2.284 per million British thermal units (mmBtu).

"Production hasn't been rising compared with demand estimate and weather models have added some degree days, indicating that we should see some higher demand. We had Hurricane Francine limit some of the LNG exports and brought some cooler weather through but now that seems to have worked through the majority of the country. We've seen LNG pop back up and power burns are stronger," said Robert DiDona of Energy Ventures Analysis.

About 10% of gas outputin the U.S. Gulf of Mexico remained offline in the aftermath of Francine, the U.S. Bureau of Safety and Environmental Enforcement (BSEE) said on Tuesday. The storm which hit the Gulf last week had shut in about half of the region's gas production.

Financial firm LSEG estimated 132 cooling degree days (CDDs) over the next two weeks, lower than Tuesday's 134 CDDs. The normal for this time of year is 91 CDDs. Cooling degree days, used to estimate demand to cool homes and businesses, measure the number of degrees a day's average temperature is above 65 degrees Fahrenheit (18 degrees Celsius).

LSEG forecast average gas demand in the Lower 48, including exports, to rise from 100.1 billion cubic feet per daythis week to 100.5 bcfd next week. LSEG forecast average gas supply in the Lower 48, including exports, at 101.8 bcfd, down from 101.9 bcfd on Tuesday.

LSEG said gas output in the Lower 48 U.S. states slid to an average of 102.1 bcfd so far in September, down from 103.2 bcfd in August.

Meanwhile, fracking, a major industry in battleground state Pennsylvania, became a big issue in the presidential campaign. Industry executives said earlier that Democratic nominee Vice President Kamala Harris understands natural gas prices will rise if fracking is banned. Fracking is a technique for recovering gas and oil from shale rock.

"Market participants in general believe that fracking will be part of our future but if that's removed, then there's significant upside to prices because the cost of extracting gas and the efficiency that we've grown accustomed to would go away," Energy Ventures' DiDona said.

Elsewhere, Japan's import of liquefied natural gas (LNG) from Russia jumped by 49% in August to 590,000 metric tons and supplies from the U.S. were down by 41% to 380,000 tons, year-on-year, preliminary customs data showed.

Dutch and British wholesale gas prices were mostly down on Wednesday morning amid stable supply. NG/EU

Reporting by Rahul Paswan in Bengaluru; Editing by Louise Heavens and Marguerita Choy

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