Natural-gas futures surged to their highest point in a week on unexpectedly strong winter demand. The front-month April contract settled up 7.2 cents, or 2.6%, at $2.841 a million British thermal units on the New York Mercantile Exchange. It was the third-straight session of gains and the highest closing price since Feb. 25. The lingering arctic chill led to the largest ever draw from stockpiles for the second half of February, the U.S. Energy Information Administration said. Storage levels fell by 228 billion cubic feet in the week ended Feb. 27. That is 3 bcf more than the 225-bcf consensus average of 15 forecasters surveyed by The Wall Street Journal. Half of U.S. homes use natural gas for heating fuel, so single-digit temperatures like those lingering this week are big drivers for demand. February was the coldest in 30 years, according to Commodity Weather Group LLC. […]