Houston (Platts)--21Oct2009/502 pm EDT/2102 GMT

Several nuclear power plant outages and a rallying November NYMEX natural gas futures contract combined to lift Northeast spot gas prices as much as 25 cents higher Wednesday.

The stronger prompt-month contract gave cash prices support as did maintenance outages at four nuclear plants, which contributed to some stout power prices in the region.

"There were a lot of power guys out there today," one trader said. "You saw a lot of buying. Power prices were up with that combination of the outages and some cool weather."

Temperatures in New England and the Mid-Atlantic were forecast to be largely on the high side of seasonal levels, but overnight lows are expected to be in the lower 40s on Thursday.

According to the US Nuclear Regulatory Commission, the four units--Beaver Valley-2 in Pennsylvania, Millstone-1 in Connecticut, Salem-2 in New Jersey and Seabrook-1 in New Hampshire--were offline.

Algonquin Gas Transmission city-gate prices jumped almost 25 cents to hit the mid-$5.30s/MMBtu on the IntercontinentalExchange.

The jump in prices in the northern parts of the region made transportation more profitable, as spreads to Canada widened, the trader said.

"It's the first time in a long time I can say that it makes sense to flow gas in from Canada. The spreads there were good," the trader added.

However, he warned that the increases in cash prices and volatility of late may soon come to an end. "I think we've seen the top of the market" on intra-regional basis trades, he added.

In addition, a chillier start to the weekend could provide for some heating demand and provide some boost for prices at week's end, sources said.

Daytime highs in New York City are forecast to fall from the mid-70s on Thursday to the upper 50s on Friday and a few degrees lower by October 25.

--Adam Bennett, adam_bennett@platts.com