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Weather Storage Shock Index

A classification of whether weather is pushing US gas storage away from normal.


The Weather Storage Shock Index (WSSI-US) measures population-weighted heating and cooling demand against normal and relates it to the weekly EIA storage change. It answers: will weather cause a storage surprise?

Overview​

WSSI-US focuses on weather-driven demand anomalies and how much of a storage week's move is attributable to weather. It is not a forecast of the EIA print or of prices.


It addresses questions such as:


  • Is forecast weather demand above or below normal for the coming EIA week?
  • How much of a storage week's move is attributable to weather (storage_attribution)?
  • Are the forecasts stable enough to rely on?

WSSI-US classifies weather-driven storage pressure; it does not predict prices.

Interpretation Guide​

WSSI-US is designed to highlight weather-driven shocks relative to expectations or norms. It should be interpreted alongside forecasts, realised outcomes, and prevailing market positioning.

Reading elevated shocks​

Elevated readings indicate forecast weather demand that differs meaningfully from normal. Colder than normal implies a larger withdrawal, so the demand anomaly is inversely related to the signed storage surprise.

This does not imply sustained trends or a price direction.

Reading low shock conditions​

Lower readings indicate weather demand broadly in line with normal. Off-season, the link between weather and storage is close to zero.

Changes through time​

The clustering or persistence of shocks can be informative, particularly when repeated deviations occur in the same direction. Isolated shocks, by contrast, may dissipate quickly.

Relationship to events​

WSSI-US Events provide discrete markers around notable demand anomalies and forecast changes.

Use within a broader framework​

WSSI-US is most effective when used alongside balance indicators and storage data.

Explore WSSI-US further​

To explore WSSI-US in more detail: