UK GAS-Prompt prices rise due to undersupply, lower wind output

LONDON, Jan 4 (Reuters) - Prompt British wholesale gas prices rose on Thursday morning due to undersupply and higher gas-for-power demand because of reduced wind output. * Within-day gas was 0.60 pence higher at 51.85 pence per therm at 0835 GMT, while day-ahead gas was up 0.30 pence at 52.40 p/therm. * The system is undersupplied by around 7 million cubic metres (mcm), with demand forecast at almost 322 mcm and flows at 329 mcm/day, National Grid (LSE: NG.L - news) data shows. * Gas-for-power consumption has risen due to reduced wind output while imports from Europe through the InterconnectorUK pipeline have declined. * "Colder weather is also expected which is a bullish factor," a UK gas trader said. * Although temperatures are above normal currently, they are forecast to drop to below-average levels from Friday to Jan. 17 which should lift heating demand. * From Jan. 6-14, temperatures are expected to be 1.5-2 degrees Celsius below normal, said Thomson Reuters (Dusseldorf: TOC.DU - news) gas analyst Oliver Sanderson. * However, further along the curve, prices declined. The February contract was down 0.90 pence at 54.00 p/therm and the Summer 2018 contract was 0.20 pence lower at 44.90 p/therm. * The day-ahead gas price at the Dutch TTF hub declined by 0.05 euro to 19.00 euros per megawatt-hour due to strong Norwegian and Russian flows. * Benchmark Dec-18 EU carbon contract inched up by 0.03 euro to 7.86 euros per tonne. * Thomson Reuters analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas (Reporting by Nina Chestney)