Following a review of Non Storage Supplies so far this winter, the assumptions in the GBA Trigger level calculation have been reviewed. This has resulted in an increase in the assumed level from non storage supplies of 20 mcm.

In addition, another storage site has reached a level where it has less than 2 days withdrawal remaining at max deliverability rates and has therefore been removed from the GBA Trigger calculation.

The GBA Trigger level now stands at 461mcm. All aspects of this remain under review.

As a result of the change of assumptions in non storage supplies, the safety monitor figures have been reviewed. The new Safety Monitors can be viewed in the Daily GBA and Storage Monitor Position Report published within the Operational Data/Gas Balancing Alerts section of the National Grid Website (http://www.nationalgrid.com/uk/Gas/Data/GBA/)