The working gas in storage estimates on lower and upper bounds are seasonally adjusted figures. The reference point for the deviations is the mid point of the lower and upper bounds.
Storage serves as a buffer supply that operators rely on to satisfy demands at peak.
Deviations in storage volumes from the mid point generally relate inversely to corresponding price movements. The lessened supplies available to the market throughout the heating season resulted in a price surge, which only diminished as weather warmed. The limited demand due to warm El Nin temperatures and the ample supplies in storage led to prices that declined through most of the heating season. The relative gas abundance signaled by the low prices led to low reliance on storage volumes, and so stock levels ended well above normal by March 1998.