(Adds latest prices) April 4 (Reuters) - U.S. natural gas futures held mostly steady on Tuesday as the market balanced rising amounts of gas flowing to liquefied natural gas (LNG) export plants versus forecasts for milder weather that will reduce heating demand over the next two weeks. The amount of gas flowing to LNG export plants was on track to hit for a second month in a row in April after Freeport LNG's facility in Texas exited an eight-month outage in February and returned to full power over the past week. Freeport LNG shut in June 2022 after a fire. Front-month gas futures for May delivery on the New York Mercantile Exchange (NYMEX) rose 0.9 cents, or 0.4%, to settle at $2.106 per million British thermal units. The market has been extremely volatile in recent weeks with the front-month gaining or losing more than 5% in 12 of the past 22 trading days. With gas market volatility rising, open interest in NYMEX gas futures rose to 1.35 million contracts on Monday, the most since October 2021 for a third day in a row. Freeport LNG's export plant was on track to pull in about 2.2 billion cubic feet per day (bcfd) of gas on Tuesday, down from 2.3 bcfd on Monday, according to data provider Refinitiv. That, however, was still more than the 2.1 bcfd of gas Freeport LNG can turn into LNG for export. LNG plants can pull in more gas than they can turn into LNG because they use some of the fuel to power equipment used to produce LNG. Average gas flows to all seven big U.S. LNG export plants rose to 14.1 bcfd so far in April, up from a record 13.2 bcfd in March. The seven big U.S. LNG export plants can turn about 13.8 bcfd of gas into LNG. SUPPLY AND DEMAND Refinitiv said average gas output in the U.S. Lower 48 states rose to 99.9 bcfd so far in April, up from 99.7 bcfd in March. That compares with a monthly record of 100.4 bcfd in January 2023. On a daily basis, however, gas output was on track to plunge 2.8 bcfd to a preliminary two-month low of 97.8 bcfd on Tuesday. But traders noted it was likely that daily decline, which would be the biggest since December, would be revised later in the day. Meteorologists projected the weather in the Lower 48 states would remain mostly warmer than normal through April 19, except for a few days from April 6-8 that will be near to colder than normal. With warmer spring-like weather expected to keep reducing the amount of gas burned to heat homes and businesses, Refinitiv forecast U.S. gas demand, including exports, would drop from 102.1 bcfd this week to 96.7 bcfd next week. Those forecasts were lower than Refinitiv's outlook on Monday. Mostly mild weather over the 2022-2023 winter allowed utilities to leave more gas in storage than usual and should enable them start injecting fuel into inventories this week. Gas stockpiles were about 21% above their five-year average (2018-2022) during the week ended March 24 and were expected to end about 20% above normal during the colder-than-normal week ended March 31, according to federal data and analysts' estimates. Week ended Week ended Year ago Five-year Mar 31 Mar 24 Mar 31 average (Forecast) (Actual) Mar 31 U.S. weekly natgas storage change (bcf): -20 -47 -24 0 U.S. total natgas in storage (bcf): 1,833 1,853 1,387 1,532 U.S. total storage versus 5-year average 19.6% 21.0% Global Gas Benchmark Futures ($ per mmBtu) Current Day Prior Day This Month Prior Year Five Year Last Year Average Average 2022 (2018-2022) Henry Hub 2.12 2.10 6.70 6.54 3.60 Title Transfer Facility (TTF) 15.58 15.50 31.83 40.50 14.39 Japan Korea Marker (JKM) 12.75 13.52 29.22 34.11 14.31 Refinitiv Heating (HDD), Cooling (CDD) and Total (TDD) Degree Days Two-Week Total Forecast Current Day Prior Day Prior Year 10-Year 30-Year Norm Norm U.S. GFS HDDs 127 140 191 184 180 U.S. GFS CDDs 42 39 32 29 27 U.S. GFS TDDs 169 179 223 213 207 Refinitiv U.S. Weekly GFS Supply and Demand Forecasts Prior Week Current Next Week This Week Five-Year Week Last Year Average For Month U.S. Supply (bcfd) U.S. Lower 48 Dry Production 100.1 100.0 100.4 95.6 89.7 U.S. Imports from Canada 6.9 6.5 7.1 8.9 8.6 U.S. LNG Imports 0.0 0.0 0.0 0.0 0.1 Total U.S. Supply 107.0 106.6 107.6 104.5 98.4 U.S. Demand (bcfd) U.S. Exports to Canada 2.8 2.1 2.0 2.5 2.6 U.S. Exports to Mexico 5.5 5.4 5.1 5.6 5.1 U.S. LNG Exports 13.2 14.1 13.7 12.5 7.1 U.S. Commercial 11.5 9.2 7.8 9.8 8.7 U.S. Residential 17.7 13.2 10.3 13.9 12.5 U.S. Power Plant 29.8 29.0 29.2 25.6 24.9 U.S. Industrial 22.8 21.9 21.5 23.1 22.5 U.S. Plant Fuel 4.9 4.9 5.0 4.9 4.9 U.S. Pipe Distribution 2.4 2.1 2.0 2.4 2.4 U.S. Vehicle Fuel 0.1 0.1 0.1 0.1 0.1 Total U.S. Consumption 89.2 80.5 75.9 79.8 76.0 Total U.S. Demand 110.7 102.1 96.7 100.4 90.8 U.S. weekly power generation percent by fuel - EIA Week ended Week ended Week ended Week ended Week ended Apr 1 Mar 31 Mar 24 Mar 17 Mar 10 Wind 18 14 14 15 12 Solar 4 4 3 3 3 Hydro 7 7 7 7 7 Other 2 2 2 2 2 Petroleum 0 0 0 0 0 Natural Gas 35 39 37 37 41 Coal 14 16 17 16 16 Nuclear 20 19 18 19 20 SNL U.S. Natural Gas Next-Day Prices ($ per mmBtu) Hub Current Day Prior Day Henry Hub 2.09 2.10 Transco Z6 New York 1.98 1.81 PG&E Citygate 7.48 6.36 Eastern Gas (old Dominion South) 1.80 1.79 Chicago Citygate 2.00 2.09 Algonquin Citygate 2.15 2.00 SoCal Citygate 8.55 7.50 Waha Hub 1.55 1.13 AECO 1.94 1.88 SNL U.S. Power Next-Day Prices ($ per megawatt-hour) Hub Current Day Prior Day New England 28.75 29.75 PJM West 31.50 26.00 Ercot North 23.70 42.50 Mid C 100.20 97.00 Palo Verde 36.25 26.00 SP-15 35.25 25.00 (Reporting by Scott DiSavino Editing by Bernadette Baum and Sandra Maler)