Prompt gas prices on the UK's NBP were lower Monday morning as the system opened long on gas.
At 11:00 am in the UK, the within-day contract was valued at 47.20 pence/therm, down by 1.80 p/th from Friday's close, while the day-ahead contract fell by 0.85 p/th to 47.45 p/th.
The system was long on gas, despite Norway having a heavy maintenance day offshore Monday.
UK system operator National Grid forecast daily demand at 156 million cubic meters in its 10:00 am figures, but estimated supplies for the day at 164 million cu m, making the system 8 million cu m long.
Demand is back below the seasonal norm. The weather is relatively mild and the UK-Belgium Interconnector pipeline is only carrying 8 million cu m/day out of the UK to Belgium.
Norwegian exporter Gassco dropped the day's aggregate impact from its offshore maintenance work down to 92 million cu m from a previously expected 109 million cu m. The impact falls back to 46 million cu m Tuesday then picks up to 59 million cu m/d until September 23.
Gassco announced during the morning a reduction in the scope of planned maintenance on the Karsto plant on Tuesday by 17 million cu m/d to 46 million cu m/d.
It is due to enter maintenance between 06:00 CEST (0400 GMT) September 9 for 24 hours for a "yearly ESD test."
Norwegian maintenance affects production for both the UK and the Continent.
Norway's Langeled line was in fact flowing fairly high rates to the UK overnight, with the pipe hitting 35 million cu m/d, before dipping to 25 million cu m/d Monday morning. The line can carry up to 70 million cu m/d at full.
UK storage is 96% full, according to Gas Storage Europe, requiring little injection.
The country's main storage facility, Rough, in any case began maintenance on Saturday, which means no injections are possible. Rough is out, also closed for withdrawals, until early September 25.
Sendout from the UK's South Hook LNG terminal remains subdued at 18 million cu m/d Monday, down from averages over 40 million cu m/d from May to August.
Tanker deliveries have slowed recently, although one Qatari vessel, the AL Mafyar, is now expected on September 12.
Gas for October delivery was seen trading at 50.30 p/th during the morning and Winter 14 at 59.85 p/th. The two contracts closed Friday's session at 50.70 p/th and 59.90 p/th, respectively.