* Spot gas up 0.50 pence to 34.00 pence per therm
* Mid-range storage sites swing from withdrawal to injection
Sept 28 (Reuters) - British wholesale prompt gas prices rose in thin trade on Wednesday as storage sites ceased pumping out supply and as analysts forecast stronger day-ahead demand.
Gas for instant delivery rose by 0.50 pence to 34 pence per therm by 0940 GMT due to sharp drop in output from storage facilities.
Gas storage sites cancelled planned withdrawals of close to 20 mcm/day on Wednesday and will now be injecting minor volumes instead, helping to tighten the system.
Britain’s gas market, however, remains 5.4 million cubic metres/day (mcm/day) long with demand estimated at 177.2 mcm/day and supply at 182.6 mcm/day, according to National Grid data.
The day-ahead gas contract gained 0.90 pence to 33.90 pence per therm, possibly responding to stronger than expected local distribution zone (LDZ) demand forecasts.
Thomson Reuters analysts pegged LDZ demand for Thursday at 6 mcm/day above previous estimates.
Britain is also not set to receive any liquefied natural gas (LNG) tankers over the next two weeks given sailing times from Qatar, Britain’s biggest supplier.
Extended and ongoing outages at the Dimlington and Barrow import terminals, respectively, also weighed on supply.
Norwegian flows through the Langeled pipeline rose to 15 mcm/day from 12 mcm/day on Tuesday.
Gas prices on the curve also rose, supported by firming oil prices.
The Winter ‘16 contract rose by 0.75 pence to 41.50 pence per therm and the Summer ‘17 contract was up by 0.46 p to 37.90 pence per therm.
In the Netherlands, the day-ahead gas price at the TTF hub was up 0.22 euros at 13.07 euros per megawatt-hour (MWh).
In the European carbon market, the benchmark Dec. 16 contract rose by 0.18 euros to 4.61 euros a tonne. (Reporting By Oleg Vukmanovic, editing by Nina Chestney)