* Front month hit highest mark since July 2011 on Monday * Below-normal temperatures remain on tap for consuming regions * Nuclear power plant outages still above normal * Coming Up: EIA natgas storage data 10:30 a.m. EDT (1430 GMT By Eileen Houlihan NEW YORK, April 18 (Reuters) - U.S. natural gas futures were little changed on Thursday, as forecasts for continued below-normal temperatures in consuming regions and above-normal nuclear power plant outages lent support ahead of the season's first storage injection. While futures remained below Monday's highest mark in more than 20 months, a tighter supply picture and ongoing power plant maintenance have helped underpin prices. Gas futures are up about 35 percent since mid-February, after cold late-winter weather put a huge dent in inventories. But most traders expect further upside to be difficult, with milder, spring-like temperatures likely to curb heating demand by late this month, before warmer weather sparks any early cooling demand. Weekly data from the U.S. Energy Information Administration is expected to show a build of about 34 billion cubic feet when it is released at 10:30 a.m. EDT (1430 GMT), a Reuters poll of industry analysts showed. Stocks rose an adjusted 21 bcf during the same week last year, and on average over the past five years have gained 39 bcf that week. As of 9:11 a.m. EDT (1311 GMT), front-month May natural gas futures on the New York Mercantile Exchange were at $4.216 per million British thermal units, up 0.2 cent, after trading between $4.175 and $4.231. The contract rose to $4.29 on Monday, the highest level for a nearby contact since late July 2011. The National Weather Service's latest six-to-10-day forecast, issued on Wednesday, again called for below-normal temperatures for about the eastern half of the nation and mostly above-normal readings in the West. Nuclear outages totaled 28,500 megawatts, or 28 percent of U.S. capacity, up from 26,800 MW out on Wednesday, 25,700 MW out a year ago, and a five-year average outage rate of 25,500 MW. INVENTORIES END WINTER BELOW AVERAGE Last week's EIA gas storage report showed domestic inventories fell in the prior week by 14 bcf, below Reuters poll estimates for a 21 bcf draw but above the year-ago gain of 11 bcf and the five-year average build of 15 bcf for that week. Domestic gas inventories of 1.673 trillion cubic feet are nearly 33 percent below last year's record high and nearly 4 percent below the five-year average. Inventories started the heating season at record highs, but two weeks ago, stocks slid below the five-year norm for the first time since September 2011. Last week's inventory decline should be the last of the heating season, however, with estimates for this week's report all looking for a modest build. Total gas pulled from storage this winter was about 2.25 tcf - roughly 770 bcf, or 52 percent, more than last year and about 15 percent more than the normal heating-season draw. Baker Hughes data last week showed the gas-directed drilling rig count rose 2 from the prior week's 14-year low, to 377.