UK GAS-Prices down on warm weather and strong wind forecasts

Nov 17 (Reuters) - British wholesale gas prices fell on Friday, driven by forecasts for warmer weather and strong wind, as below seasonal-average demand and high Norwegian flows created an oversupplied system, said traders. * Day-ahead gas was down 0.58 pence to 51.80 pence per therm at 0949 GMT. * Within-day gas fell by 0.15 pence at 51.90 pence per therm. * "Quite a weather change all in all and windier weather will definitely have its impact, from bit below normal/low wind to above normal with normal winds", said a British gas trader, explaining the price slip. * Peak wind power generation is forecast at 7.7 gigawatts (GW) on Friday but expected to rise to 8.3 GW on Saturday (Shenzhen: 002291.SZ - news) , Elexon data showed. * Higher wind output typically results in lower demand from gas-to-power plants. * Average temperatures on Friday could reach 9 degrees Celsius in southern Britain and are expected to rise to 12 degrees on Monday, data from Britain's Met Office showed. * Britain's gas system was oversupplied by 4.5 million cubic metres (mcm), with demand forecast at 264.7 mcm and supply at 269.2 mcm/day, National Grid (LSE: NG.L - news) data showed. * Gas supply from Norway to Britain on Friday reached 121 mcm/day, remaining at high levels even though 5 mcm/day lower from Thursday. * Britain's gas demand on Friday was 13.3 mcm lower than the seasonal normal demand, National Grid data showed. * The December contract was down by 0.65 pence at 52.20 pence/therm. * In the Dutch gas market, the day-ahead gas price at the TTF hub fell by 0.22 euro to 18.95 euros per megawatt hour (MWh). * The benchmark Dec (Shanghai: 600875.SS - news) -17 EU carbon contract fell by 0.03 euro to 7.47 euros a tonne. * Thomson Reuters (Dusseldorf: TOC.DU - news) analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas (Reporting by Lefteris Karagiannopoulos in Oslo; Editing by Jon Boyle)