U.S. natural gas prices extended a slide that started earlier this month in forecasts of warmer weather on the horizon. In morning trade in Asia today, the futures contract for March shed 7.4% from Friday, to just above $3 per million British thermal units, the lowest price level seen since mid-October last year. Earlier in the year, natural gas prices soared to the highest in years amid freezing winter weather that gripped most of the United States, driving demand for heating much higher, with wind and solar largely unable to respond to this demand…