* Demand around 90 mcm above seasonal norm
* Within-day up over 5 pct at 32.80 p/therm
LONDON, April 26 (Reuters) - British wholesale gas prices rose on Tuesday as demand surged and some supplies were disrupted.
Gas for within-day delivery jumped 1.60 pence, or 5.13 percent, to 32.80 pence per therm by 0807 GMT from the last settlement, while gas for day-ahead delivery was up 1.25 pence at 32.90 p/therm.
The latest weather models point to temperatures remaining significantly colder than normal until at least May 3, with some showing colder weather to last until May 8, said analysts at UK-based consultancy Energy Aspects.
"As such, we expect heating demand in the region to continue to be higher year-on-year by around 60 percent (2.2 billion cubic metres) over the next two weeks, driven by higher year-on-year demand from all the western European countries," they added.
The gas system was around 19.7 mcm undersupplied on Tuesday due to lower flows from the UK Continental Shelf as an outage at Easington terminal continued.
Outages in the Norwegian Continental Shelf have also disrupted supplies through the Langeled pipeline.
In the Netherlands' gas market, the day-ahead price at the TTF hub inched up by 0.27 euros to 13.52 euros per megawatt-hour. In Europe's carbon market, the front-year EU allowance price was 0.23 euro higher at 6.13 euros a tonne. (Reporting by Nina Chestney; Editing by Susan Fenton)