UPDATE 1-New front-month May U.S. natgas futures at 18-month high

* Front month at highest mark since mid-September 2011

* Nuclear outages still running above normal

* Cold weather remains on tap in long-term forecasts

(Adds cash prices, updates futures prices)

By Eileen Houlihan

NEW YORK, March 27 (Reuters) - U.S. natural gas futures rose more than 1 percent early on Wednesday, with the new front-month May contract reaching its highest mark in more than 18 months amid lingering cold weather in consuming regions of the nation.

Cold weather has put a huge dent in inventories and helped drive gas futures up 25 percent since mid-February.

Above-normal nuclear power plant outages have also increased demand for gas-fired replacement power and underpinned price gains.

But some traders said gas was due for a pullback, with winter-like weather winding down and with the nearby contract failing to close above $4 per million British thermal units after poking through that level last week.

As of 9:51 a.m. EDT (1351 GMT), May natural gas futures on the New York Mercantile Exchange

were at $4.04 per mmBtu, up 4.9 cents, or about 1 percent, after rising as high as $4.078 in electronic trade, the highest mark for a spot contract since mid-September 2011.

In the cash market, gas for Thursday delivery at the NYMEX benchmark Henry Hub

in Louisiana was heard early up 9 cents at $4.08, tying its nearly 19-month high hit on Monday. Volume was light at 344 million cubic feet.

Early deals were done at 5 cents over the May contract, compared with deals done late Tuesday at 11 cents over the April contract.

Gas on the Transco pipeline at the New York citygate

, however, was heard down 4 cents early at $4.24 on volume near 114 mmcf.

Forecaster MDA Weather Services, in its one to five-day outlook, called for normal or below-normal temperatures for a little more than the eastern half of the country, with above-normal readings in the West.

The National Weather Service's latest six to 10-day forecast, issued on Tuesday, also called for below-normal readings in the East and above-normal readings in the West.

Nuclear outages totaled 21,800 megawatts, or 22 percent of U.S. capacity, down from 21,900 MW out on Tuesday and 22,100 MW out a year ago, but up from a five-year average outage rate of 19,400 MW.

INVENTORY DRAW FALLS SHORT OF EXPECTATIONS

Last week's data from the U.S. Energy Information Administration showed total domestic gas inventories fell in the prior week by 62 billion cubic feet, below Reuters poll estimates for a 70 bcf draw.

It was the first time in five weeks that the weekly draw fell short of expectations.

Domestic gas inventories are now at 1.876 trillion cubic feet, more than 21 percent below last year's record high for this time of year but about 10 percent above the five-year average.

(Storage graphic: )

Stocks seem on track to end the heating season below 1.8 tcf, or just 3 percent above average. A Reuters poll in mid-January showed most analysts expected stocks to finish the winter at about 2 tcf.

Early withdrawal estimates for this week's inventory report range from 59 bcf to 103 bcf versus, compared with a 45-bcf build during the same week last year and a five-year average increase for the week of 6 bcf.

Baker Hughes

data last week showed the gas-directed drilling rig count fell by 13 to 418, hovering just above the recent 14-year low of 407 posted three weeks ago.

While the EIA recently lowered its growth forecast for 2013, it still expects marketed gas production to hit a record high for the third straight year.

(Editing by John Wallace)

(([e-mail], Twitter @eileenreuters)([phone])(Reuters Messaging: [e-mail]))

Keywords: MARKETS NYMEX/NATGAS