* April temperatures below-average, May-July seen warmer
* Qatargas outages cast doubt over May LNG supply
* Shell’s Bacton maintenance to tighten supply
LONDON, April 23 (Reuters) - British prompt gas prices rose on Monday morning as supply lagged demand amid colder-than-average temperatures forecast until the end of the month, while curve gas slumped with weakening oil prices.
However, average summer temperatures across Europe will be higher-than-normal between May and July, with the exception of southeastern parts of the continent, forecaster Weather Services International (WSI) said.
May gas prices rose slightly despite warm weather forecasts on the back of ongoing uncertainty over liquefied natural gas (LNG) supplies and bullish momentum feeding in from the prompt market.
UK day-ahead gas rose 0.35 pence to 60.45 pence per therm, while gas for immediate delivery gained half a penny to 60.75 pence.
May gas edged 0.15 pence higher to 58.55 pence.
The market was undersupplied by 10 million cubic meters/day, due to a sharp cut in storage withdrawals compared with last week levels. Withdrawals dropped to zero by 1030 GMT versus 23 mcm/day on Friday.
Higher imports from Norway and the Netherlands somewhat narrowed the supply-demand imbalance.
Offshore gas output is currently 120 mcm/day, slightly up from Friday’s average of 118 mcm/day. That rate should drop on Sunday as Shell’s Bacton terminal starts its scheduled one-day maintenance, resulting in a forecast supply loss of 11 mcm.
The current LNG send out rate is 57 mcm/d, roughly in line with Friday’s average of 62 mcm/d and also over the weekend.
Despite five gas tankers expected in Britain between now and early May, planned maintenance at three Qatargas production plants at the end of April could trigger a slowdown in arrivals.
“This results in a loss of production capacity of 3.2 million tones per annum per train. As a result, UK terminal operators could be more careful with their send out rates,” analysts at Point Carbon said.
Qatar provides the majority of Britain’s LNG supply, leaving it exposed to supply disruptions.
In France, striking workers at GDF Suez LNG terminals on Friday opted to extend their strike until today, while workers at the Montoir LNG port resume work last week.
Further out, benchmark front-season prices slumped as softer oil prices led bearish trading activity on the forward curve.
Winter 2012 gas prices traded down 0.65 pence at 69.35 pence per therm.
Spot baseload power fell 1.75 pounds to 43.60 pounds per megawatt-hour (MWh). (Reporting by Oleg Vukmanovic; Editing by Mark Potter)