UPDATE 1-US natgas prices leap 17% on cold forecasts, rising LNG feedgas

Updates prices and comparisons, adds analyst comment in paragraphs 4-5

Dec 30 (Reuters) - U.S. natural gas futures jumped more than 17% on Monday, the sharpest daily increase since late October, driven by forecasts of colder weather in January and rising export demand.

On its first day as the front-month, gas futures NGc1 for February delivery on the New York Mercantile Exchange surged 58 cents, or 17.1%, to $3.96 per million British thermal units as of 12:15 p.m. EST.

Prices are at their highest since January 2023 and are set to end the year with annual gains of over 58%, the most since 2016.

"Short-term weather models show temperatures are expected to drop much below normal in the first half of January, said Robert DiDona, president of Energy Ventures Analysis.

"So the market is really valuing this potential brutal cold snap coming up as the real economic driver of why prices are significantly higher today ... We expect lots of price volatility coming up in the next few weeks."

Financial firm LSEG estimated 499 heating degree days over the next two weeks, compared with 399 estimated on Friday. It also forecast average gas demand in the Lower 48, including exports, jumping to 148.4 bcfd this week from 120.2 bcfd last week.

Rising export demand is also supporting U.S. natural gas prices, said Gary Cunningham, director of market research at Tradition Energy.

The amount of gas flowing to the eight big U.S. LNG export plants rose to an average of 14.8 billion cubic feet per day (bcfd) so far in December from 13.6 bcfd in November, according to LSEG data. Meanwhile, natural gas production in the Lower 48 U.S. states rose to 103.3 bcfd so far in December, from 101.5 bcfd in November, the data showed.

"Global demand for the fuel (is) expected to remain high as output cuts from some North Sea assets should keep European buyers actively seeking cargoes to maintain storage levels, which have already fallen to ~60% of full in some regions," Cunningham said.

Earlier on Monday, Cheniere Energy LNG.N said that liquefied natural gas was produced for the first time from the first train (Train 1) of the company's Corpus Christi Stage 3 Liquefaction Project.

That comes after Venture Global LNG's tanker Venture Bayou departed the Plaquemines export plant in Louisiana for Germany last week, carrying the first LNG cargo produced at the facility.

Dutch and British wholesale gas prices were stable early on Monday as high output from wind and solar farms curbed demand for gas-fired power, offsetting nervousness about the expected end of Russian gas supplies to Europe via Ukraine. NG/EU

"With temperatures turning appreciably colder as this week progresses across the eastern half of the U.S. with extension of below normal trends toward mid-January according to some forecasts, the newly prompt February contract has pushed assertively through key resistance at the $3.55 level in keeping this month’s strong upside price acceleration much intact," energy advisory firm Ritterbusch and Associates said in a note.

(Reporting by Anushree Mukherjee and Sherin Elizabeth Varghese in Bengaluru, additional reporting by Swati Verma; Editing by Sharon Singleton and Alison Williams)

((anushree.ashishMukherjee@thomsonreuters.com;))

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