* Nuclear outages still running above normal * Chilly weather to continue into early April By Joe Silha NEW YORK, March 25 (Reuters) - Front-month U.S. natural gas futures ended lower on Monday for a fourth straight session, pressured by profit-taking after upside momentum stalled ahead of key resistance despite cold weather that should force homeowners and businesses to turn up the heat. Cold weather has put a huge dent in inventories and helped drive futures up about 25 percent in the previous five weeks. Above-average nuclear plant outages have also increased demand for gas-fired replacement power and underpinned price gains. But technical traders said the front contract was due a pullback, particularly ahead of Tuesday's expiration and after failing to close above key resistance at $4 per million British thermal units despite poking through that level several times last week. "Mother Nature turned really bullish in mid-February and everyone got long, but that's been priced in now and it's going to warm up eventually," said Kyle Cooper, managing partner at IAF Advisors in Houston. April natural gas futures on the New York Mercantile Exchange ended down 6.2 cents, or 1.6 percent, at $3.865 per mmBtu after trading between $3.86 and $3.996. The front-month contract, which posted an 18-month high of $4.025 on Thursday, has gained for five straight weeks but lost 2.6 percent in the last four sessions. Some traders said the market may be losing upward momentum, particularly with production flowing at or near an all-time peak and mild spring weather likely to slow demand later next month. In addition, gas prices above $4 could curb demand by prompting some utilities to use more coal to generate power and increase supply by encouraging producers to turn on more wells. Commodity Weather Group expects a seasonal to cool pattern to linger for the next week or so, but weather in early April was not expected to be as cold as the readings in late March. RIGS CLIMB, OUTPUT NOT SLOWING MUCH Baker Hughes data on Friday showed the gas-directed drilling rig count fell last week for the third time in four weeks, dropping by 13 to 418. The count is hovering just above the 14-year low of 407 posted two weeks ago, but production has not slowed much, if at all, from the record high posted last year. The Energy Information Administration still expects marketed gas production in 2013 to hit a record high for the third year. STRONG STORAGE DRAW EXPECTED U.S. EIA data last week showed domestic gas inventories for the week that ended March 15 fell by 62 billion cubic feet to 1.876 trillion cubic feet. Most traders viewed the decline as bearish, noting it fell short of market expectations for the first time in five weeks. A Reuters poll had forecast a 70-bcf draw. The drop did cut 36 bcf from the surplus versus the five-year average, but storage is 162 bcf, or 9 percent, above that benchmark. Most traders expect that surplus to shrink sharply in Thursday's inventory report, with early withdrawal estimates ranging from 59 to 103 bcf. Stocks rose 45 bcf in the same week last year, while storage normally gains by 6 bcf that week. Stocks will likely end the heating season just above the 1.73-tcf average for March 31. Storage began the winter above 3.9 tcf, and a Reuters poll in mid-January showed most analysts expected stocks to finish the season at about 2 tcf. Gas pulled from storage so far this winter is about 2.050 tcf, roughly 580 bcf, or 39 percent, more than the same time last year and nearly 5 percent above normal.