* Downward revised weather forecast helps buoy prices
* UKCS maintenance, lower Dutch imports lend support
March 8 (Reuters) - British spot gas prices rose on Tuesday morning as supplies tightened due to maintenance limiting domestic output, a slightly colder weather outlook and lower imports from the Netherlands.
Gas for instant delivery rose 0.43 pence per therm to 30.33 p/therm by 0954 GMT, while the weekend contract traded at 28.50 p/therm, up 0.60 p/therm.
Only gas for Wednesday delivery bucked the upward trend, trading 0.10 p/therm lower at 30 p/therm.
Britain also resumed exporting small amounts of gas to Belgium, further tightening supply.
Temperatures forecasts for this week were revised overnight to slightly colder than previously expected, traders said, which was helping to support gains on the prompt.
"There is a two degree (Celsius) drop in temperature forecasts for the weekend, now expected at 5-6 degrees Celsius, and also European forecasts are slightly cooler than expected," one trader said, adding that there is still a warming trend overall.
Generally, forecasters predict gradually milder temperatures this week, while Thomson Reuters (Dusseldorf: TOC.DU - news) analysts expect this to erode local distribution zone demand - for heating - to 180 mcm/day next week from around 230 mcm/day this week.
"Some further wet and windy weather (is forecast) for the next few days but gradually turning more settled and also milder by the end of the week," Britain's Met Office said in a statement.
Meanwhile, maintenance at Britain's Bacton Seal terminal has cut flows to 5 mcm/day compared with typical rates of 15 mcm/day. Flows from the Netherlands through the BBL pipeline dropped to 25 mcm/day from 32.5 mcm/day on Monday.
Send-out from the South Hook liquefied natural gas (LNG) terminal also declined to around 30 mcm/day, versus above 40 mcm/day in the previous trading session.
Further along the curve, the UK summer 2016 gas contract was 0.15 penny higher at 27.15 p/therm, supported by a recent rise in oil prices above $40 a barrel, which may also be helping fuel gains on the prompt, a trader said.
In the Dutch gas market, day-ahead prices at the TTF hub inched down by 0.05 euro to 12.43 euros per megawatt-hour.
Brent crude futures managed to defend $40 per barrel, standing at $40.43 at 0742 GMT, down 41 cents from its last settlement.
In the European carbon market, front-year allowances edged down by 0.09 euro to 5.01 euros a tonne. (Reporting by Oleg Vukmanovic)