UK GAS-Within-day price up on high demand, day-ahead down on warmer weather

Nov 2 (Reuters) - Prompt British wholesale gas prices were mixed on Thursday. High flows from Norway, nearly at maximum capacity, and expectations for warmer weather drove the day-ahead lower, while weak wind output and high demand raised the within-day price, traders said.

* The within-day gas price was up 0.05 pence at 47.85 pence per therm by 0937 GMT. * Day-ahead gas fell by 0.35 pence to 48.00 pence per therm. * The high Norwegian gas flows and expectations for higher temperatures caused the day-ahead contract's price to fall, said a British gas trader. * A second trader attributed the within-day price hike to Thursday's high demand and weak renewable energy output. * Britain's gas system was oversupplied by 9.4 million cubic metres (mcm), with demand forecast at 263.9 mcm and supply at 273.3 mcm/day, National Grid (LSE: NG.L - news) data showed. * Britain's gas demand on Thursday was 4.2 mcm higher than the seasonal normal demand, National Grid data showed. * Gas supply from Norway to Britain on Thursday reached almost the pipelines' maximum capacity at 137 mcm/day, up 22 mcm/day from Wednesday. * Average temperatures on Thursday could reach 12 degrees Celsius in southern Britain and are expected to rise to 14 degrees on Friday, data from Britain's Met Office showed. * Peak wind power generation is forecast at 3.5 gigawatts (GW) on Thursday but expected to fall to 2.4 GW on Friday, Elexon data showed. * Lower wind output typically results in higher demand for gas from power plants. * In the Dutch gas market, the day-ahead gas price at the TTF hub fell by 0.18 euro to 18.20 euros per megawatt hour (MWh). * The benchmark Dec (Shanghai: 600875.SS - news) -17 EU carbon contract rose by 0.04 euro to 7.55 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 Mark Potter)