* Rough, Langeled gas flows turn down
* Traders watching for diverted LNG tankers
* Hartlepool 2 nuclear reactor shuts for unplanned work
LONDON, Oct 21 (Reuters) - British gas prices firmed on Thursday after Rough storage withdrawals turned down and Norwegian flows via Langeled edged lower, effectively lifting the whole curve on a tighter system, traders said.
Gas for Friday traded at 47.85 pence per therm at 1133 GMT, up 0.40 pence from the previous session day-ahead close, while November was up 0.25 pence at 47.35 pence ($7.48 per mmbtu) and December increased 0.45 pence 48.90 pence.
“Storage flows are down. Langeled’s flowing 57 mcm (million cubic metres) instead of 65 or 70, so just tightening the system and the curve is going with it,” one gas trader said.
National Grid data showed Rough flows fell 14 mcm to 6 mcm early in the session before resuming withdrawals, while Langeled dropped around 6 mcm. Supplies were tight, with Thursday UK gas demand forecast to be 45 mcm above seasonal norms at 337 mcm, National Grid website showed.
Traders were also watching for diverted liquefied natural gas (LNG) tankers, with French strikes obstructing vessels from offloading cargo at the Montoir and Fos terminals.
Two vessels that were in Montoir port on Tuesday were no longer there on Wednesday but had not shown up on UK port schedules on Thursday. [ID:nLDE69J0TI]
In the British power market, prices were near flat, with baseload power for Friday trading at 43.20 pounds per megawatt-hour (MWh) compared with day-ahead prices of 43.50 pounds on Wednesday, with the N2EX power exchange settling the price at 43.33 pounds.
The market shrugged off an unplanned outage at Hartlepool 2 nuclear reactor, with supply margins still comfortable. [ID:nWLA5955] (Reporting by Kwok W. Wan; editing by Sue Thomas)