Dec 17 (Reuters) - U.S. natural gas futures fell 2% on Friday to a one-week low on record output and forecasts for milder weather through late December than previously expected. Mostly mild weather since mid-November has kept heating demand low and allowed utilities to leave so much gas in storage that there will soon be more of the fuel in stockpiles than is usual for the time of year for the first time since April. The U.S. futures decline came despite near-record gas prices in Europe and Asia that were over 11 times higher than U.S. prices and should keep demand for U.S. liquefied natural gas exports (LNG) strong for months to come. Front-month gas futures fell 7.6 cents, or 2.0%, to settle at $3.690 per million British thermal units (mmBtu), their lowest close since the contract settled at a four-month low on Dec. 6. For the week, the contract fell about 6%, putting it down for a third week in a row. The premium of March 2021 futures over April 2021 slid to a record low of around 5 cents per mmBtu. The industry uses the March-April spread to bet on the winter heating season when demand for gas peaks. read more That puts the March-April spread, known as the "widow maker", close to going into contango with summer contracts (April) trading over winter contracts (March) even before the official start of winter with the solstice on Dec. 21. The industry calls the March-April spread the widow-maker because rapid price moves resulting from changing weather forecasts have knocked some speculators out of business, including the Amaranth hedge fund, which lost more than $6 billion on gas futures in 2006. In the spot market, next-day power prices in New England spiked to their highest since January 2018 on forecasts the region will experience its first winter cold snap next week. read more Global gas prices have repeatedly reached all-time highs over the last few months as utilities around the world scrambled for LNG cargoes to replenish low stockpiles in Europe and meet surging demand in Asia, where energy shortfalls caused power blackouts in China. U.S. futures jumped to a 12-year high of more than $6 per mmBtu in early October, but have retreated because the United States has plenty of gas in storage and ample production for winter. Analysts have said European inventories were about 20% below normal for this time of year, compared with just 2% below normal in the United States. Data provider Refinitiv said output in the U.S. Lower 48 states has averaged 96.8 billion cubic feet per day (bcfd) so far in December, which would top the monthly record of 96.5 bcfd in November. Refinitiv projected average U.S. gas demand, including exports, would jump from 109.7 bcfd this week to 120.6 bcfd next week and 123.6 bcfd in two weeks as the weather turns seasonally colder. Those forecasts were higher than Refinitiv"s outlook on Thursday. The amount of gas flowing to U.S. LNG export plants has averaged 11.9 bcfd so far in December, now that the sixth train at Cheniere Energy Inc"s (LNG.A) Sabine Pass plant in Louisiana is producing LNG. That compares to 11.4 bcfd in November and a monthly record of 11.5 bcfd in April. Week ended Dec 17 (Forecast) Week ended Dec 10 (Actual) Year ago Dec 17 Five-year average Dec 17 U.S. weekly natgas storage change (bcf): -64 -88 -147 -153 U.S. total natgas in storage (bcf): 3,353 3,417 3,496 3,328 U.S. total storage versus 5-year average +0.8 -1.8% Global Gas Benchmark Futures ($ per mmBtu) Current Day Prior Day This Month Last Year Prior Year Average 2020 Five Year Average (2016-2020) Henry Hub 3.70 3.77 2.58 2.13 2.66 Title Transfer Facility (TTF) 44.78 45.08 5.82 3.24 5.19 Japan Korea Marker (JKM) 43.45 43.20 9.46 4.22 6.49 Refinitiv Heating (HDD), Cooling (CDD) and Total (TDD) Degree Days Two-Week Total Forecast Current Day Prior Day Prior Year 10-Year Norm 30-Year Norm U.S. GFS HDDs 401 404 409 414 420 U.S. GFS CDDs 8 8 2 5 4 U.S. GFS TDDs 409 412 411 419 424 Refinitiv U.S. Weekly GFS Supply and Demand Forecasts Prior Week Current Week Next Week This Week Last Year Five-Year Average For Month U.S. Supply (bcfd) U.S. Lower 48 Dry Production 96.6 96.8 96.8 91.3 84.7 U.S. Imports from Canada 8.7 8.0 8.7 9.5 8.9 U.S. LNG Imports 0.0 0.0 0.0 0.4 0.3 Total U.S. Supply 105.3 104.9 105.5 101.2 93.9 U.S. Demand (bcfd) U.S. Exports to Canada 3.6 3.7 3.7 2.8 3.0 U.S. Exports to Mexico 5.7 5.4 5.5 5.6 4.6 U.S. LNG Exports 12.1 11.9 12.5 11.0 5.0 U.S. Commercial 13.8 12.5 15.2 16.7 15.0 U.S. Residential 21.9 20.1 25.2 28.2 25.4 U.S. Power Plant 28.4 25.6 26.4 30.1 25.8 U.S. Industrial 23.8 23.2 24.4 25.6 24.6 U.S. Plant Fuel 4.8 4.8 4.8 4.8 4.8 U.S. Pipe Distribution 2.5 2.4 2.6 2.4 2.4 U.S. Vehicle Fuel 0.1 0.1 0.1 0.1 0.1 Total U.S. Consumption 95.3 88.7 98.8 107.9 98.1 Total U.S. Demand 116.6 109.7 120.6 127.3 110.7 U.S. weekly power generation percent by fuel - EIA Week ended Dec 17 Week ended Dec 10 Week ended Dec 3 Week ended Nov 26 Week ended Nov 19 Wind 16 13 11 13 14 Solar 2 2 2 2 2 Hydro 7 7 6 6 6 Other 2 2 2 2 2 Petroleum 1 1 1 1 1 Natural Gas 33 36 37 34 35 Coal 18 19 19 20 19 Nuclear 22 21 22 22 21 SNL U.S. Natural Gas Next-Day Prices ($ per mmBtu) Hub Current Day Prior Day Henry Hub 3.67 4.79 Transco Z6 New York 2.91 2.91 PG&E Citygate 5.29 5.32 Dominion South 2.86 2.78 Chicago Citygate 3.60 3.59 Algonquin Citygate 3.89 3.46 SoCal Citygate 6.70 6.46 Waha Hub 3.40 3.41 AECO 3.42 3.43 SNL U.S. Power Next-Day Prices ($ per megawatt-hour) Hub Current Day Prior Day New England 40.50 38.00 PJM West 33.50 23.25 Ercot North 35.00 45.25 Mid C 49.50 55.00 Palo Verde 38.50 49.00 SP-15 59.00 60.25