UK GAS-Prompt prices mostly buoyant amid cold spell forecast

LONDON, Jan 2 (Reuters) - British wholesale prompt gas prices mostly rose on Tuesday in anticipation of colder temperatures lifting demand later in the week. * Day-ahead gas price up 0.65 pence at 53.65 p/therm by 1159 GMT. * Working days next week gas rose 0.80 pence to 56 p/therm. * With (Other OTC: WWTH - news) a cold spell due to start from the weekend, the forecast for residential and commercial demand was lifted 60 million cubic metres/day (mcm/day) to 258 mcm/day, analysts at Thomson Reuters said. * That compares with residential and commercial demand at 229 mcm/day on Tuesday. * A trader said the colder forecast was also helping lift prompt contracts such as day-ahead. * Weekend temperatures were revised 5.1 degrees Celsius lower to 1.9 degrees in the latest 45-day forecast. Average temperatures for working days next week were revised 3.2 degrees lower to 2.4 degrees, according to Thomson Reuters (Dusseldorf: TOC.DU - news) weather data. * However, an oversupplied network on Tuesday put downward pressure on spot gas prices, which fell 0.15 p to 53 p/therm. * Milder temperatures and higher flows from Norway on Tuesday made the system oversupplied by 15.3 mcm/day, National Grid (LSE: NG.L - news) data showed. * Demand was estimated at 314.1 mcm/day with daily supply estimated at 329.4 mcm/day. * Norwegian flows to Britain rose 9 mcm/day to 135 mcm/day. * February contract down 0.40p at 56.25p/therm * Day-ahead gas price at the Dutch TTF hub up 0.03 euro at 19.58 euros per megawatt-hour. * Benchmark Dec-18 EU carbon contract down 0.13 euro at 8.05 euros per tonne. * Thomson Reuters analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas (Reporting by Oleg Vukmanovic, Editing by Mark Potter)