* More winter weather expected for large parts of U.S.
* End-of-winter storage seen below 1 trillion cubic feet
(Updates prices) NEW YORK, Feb 19 (Reuters) - U.S. natural gas futures jumped nearly 10 percent on Wednesday to the highest in more than four years, boosted by forecasts for frigid cold weather across the United States that will further boost heating demand and deplete natural gas supplies. Traders bought futures contracts to cover short positions as prices rose, advancing the rally, brokers said. Natural gas futures for March delivery gained as much as 53.3 cents by late morning, or 9.6 percent, to reach a high of $6.085 per mmBtu, the highest since Jan. 7, 2010, when prices were at $6.108. Weather forecasters expect frigid temperatures to continue after record-cold weather in January led to steep draws of natural gas to meet heating demand, leaving less gas to meet summer electric power demand. The 11-15 day forecast points to "ongoing colder than normal conditions" over much of North America, said meteorologists at MDA Weather Services in Gaithersburg, Maryland. Temperatures in Chicago will reach sub-zero (Fahrenheit/below minus 18 degrees Celsius) at the end of next week while New York temperatures will reach into the teens, according to the MDA forecast. March gas futures on the New York Mercantile Exchange were last trading 50.9 cents higher at $6.06 per mmBtu at 11:30 a.m. EST (1630 GMT). The March contract gained as much as $1.19 over April, widening the spread between the two by some 92 cents in one week. "The rally is confined to March, but as time goes by the seriously depleted storage level is going to catch on," said Gene McGillian, analyst with Tradition Energy in Stamford, Connecticut. "The back of the board has some catching up to do."
Storage levels are expected to drop to a low of 890 billion cubic feet (bcf) at the end of March, and "we do not see a full recovery over the summer," said Thomson Reuters natural gas analyst Jan Schulte. Analysts at Thomson Reuters Point Carbon are expecting the U.S. Energy Information Administration (EIA) to report a draw of 263 bcf in Thursday's weekly inventory report. Analysts polled In the cash market, gas at the Henry Hub <GT-HH-IDX>, the benchmark supply point in Louisiana, rose 23 cents to $5.97 per mmBtu on average, a 1-cent discount to the NYMEX. Gas prices for Thursday delivery on the Transco Zone 6 pipeline <E-TSCO6NY-IDX> in New York traded 8 cents higher at $6.13 per mmBtu on average. Nuclear plant outages, which create demand for natural gas as a substitute fuel, were at 9,655 megawatts, up from 9,570 MW on Tuesday. That compares with 16,100 MW a year ago and a five-year average outage rate of 10,300 MW.
(Editing by Marguerita Choy and Bernadette Baum)