Verification of Space Weather Forecasts issued by the Met Office Space Weather Operations Centre

TL;DR

This study evaluates the accuracy of space weather forecasts issued by the UK Met Office, revealing that while they have some skill, they tend to over-forecast space weather events over a 19-month period.

Contribution

It provides a detailed verification of the Met Office's space weather forecasts using satellite and planetary data, highlighting their strengths and weaknesses.

Findings

Forecasts have some discriminatory skill.

Forecasts tend to over-forecast events.

Performance over 19 months shows limited improvement over reference.

Abstract

The Met Office Space Weather Operations Centre was founded in 2014 and part of its remit is a daily Space Weather Technical Forecast to help the UK build resilience to space weather impacts; guidance includes four day geo-magnetic storm forecasts (GMSF) and X-ray flare forecasts (XRFF). It is crucial for forecasters, users, modelers and stakeholders to understand the strengths and weaknesses of these forecasts; therefore, it is important to verify against the most reliable truth data source available. The present study contains verification results for XRFFs using GOES-15 satellite data and GMSF using planetary K-index (Kp) values from the GFZ Helmholtz Centre. To assess the value of the verification results it is helpful to compare them against a reference forecast and the frequency of occurrence during a rolling prediction period is used for this purpose. Analysis of the rolling 12-month performance over a 19-month period suggests that both the XRFF and GMSF struggle to provide a better prediction than the reference. However, a relative operating characteristic and reliability analysis of the full 19-month period reveals that although the GMSF and XRFF possess discriminatory skill, events tend to be over-forecast.