UK GAS-Prices mixed on strong wind and colder forecast

Sept 18 (Reuters) - British within-day gas price fell on Tuesday as strong wind power production reduced demand, but colder forecasts helped lift the day ahead contract.

* Day-ahead gas rose by 0.47 pence to 72.00 pence per therm by 0825 GMT

* Within-day gas price down 0.40 pence at 72.10 pence per therm

* Strong wind on Tuesday and warm weather reduced gas demand, and the within-day price as a result, as the system was left oversupplied, a British gas trader said

* Colder weather expected from Wednesday caused the rise in the day-ahead, he said

* Average daily temperatures in Britain are seen around 17.7 degrees Celsius on Tuesday and are forecast to fall to 16.2 C on Wednesday

* During the weekend temperatures are forecast to drop to 12 C, Thomson Reuters Eikon data shows

* Peak wind generation was forecast to be strong on Tuesday and Wednesday at over 9 gigawatts (GW) of the 12 GW of installed capacity

* The market is oversupplied, with demand forecast at 150.1 million cubic metres (mcm) and flows at 155.3 mcm/day, National Grid data shows

* Gas supply from Norway to Britain was low, at 49 mcm per day, largely stable for the previous day as flows through the Langeled and Vesterled pipelines remained below 50 percent of their maximum capacity

* October contract down 0.15 pence at 72.00 p/therm

* In the Dutch gas market, the day-ahead price at the TTF hub was down 0.02 euro at 27.53 euros per megawatt hour

* The benchmark Dec (Shanghai: 600875.SS - news) -18 EU carbon contract rose by 0.10 euro to 21.03 euros a tonne (Reporting by Lefteris Karagiannopoulos in Oslo; editing by Jason Neely)