* Spain day-ahead 32.87 euros/MWh, up 0.74

* Cal-10 dips 0.50 to 40.15 euros/MWh (OTC)

MADRID, Dec 14  - Near-record supplies of cheap wind power curbed gains by Iberian spot power prices on Monday, which were driven higher by a cold snap that brought snow to much of Spain.

Dealers said the benchmark day-ahead rate was surprisingly low and had traded at 35 euros in the over-the-counter market before it was fixed by the Omel exchange.

Spain's Met Office issued its first storm warning this winter for the northern half of the country and the southeast, which comes after an unusually warm autumn.

Data from national grid operator REE (REE.MC) showed that Spain's wind parks, the world's third-most powerful, were generating 11,000 megawatts or 26.5 percent of the country's electricity.

That compares with a record of 11,620 MW produced momentarily on Nov. 8.

Looking ahead, wind power is seen falling substantially on Tuesday, which normally ramps up spot prices. Demand, however, is expected to ease as daytime temperatures rise to 9 degrees by Wednesday in Madrid, the Peninsula's biggest city, from 3 on Monday.

Spain's grid is still short of 2,000 MW of nuclear power because the Almaraz I plant is refuelling and not due back until next week, and the Asco I reactor is offline for maintenance and not expected back until later this week, at the earliest.

The remaining six nuclear plants were producing 5,350 MW, or 13.1 percent of the generating mix, according to data from the national grid operator REE (REE.MC).

Renewed falls by benchmark crude prices LCOc1 further removed support for baseload forward contracts, which have been sluggish for the past two months due to low prices for essential fuels like gas. Benchmark calendar-year 2010 was heard changing hands at reported settling at 40.15 euros/MWh in over-the-counter dealing, down 0.50 on the day. On the Omip exchange, which accounts for 30 percent of forwards volume, the cal eased 0.07 to 40.23 euros/MWh.

Spain's power stations were emitting an unusually low 8,461 tonnes per hour of carbon dioxide. (Reporting by Martin Roberts, editing by Anthony Barker)