NOAA / Space Weather Prediction Center

X-class Flare Forecast Verification

Verification Quick Links
Verification Home, Max K and GPRA, G1 (K5) Warnings, G2 (K6) Warnings,
Estimated Ap, Fredericksburg A, Geomagnetic Activity Category,
M-class Flares, X-class Flares, F10.7 Solar Flux, S1 Proton Events, S1 Event Warnings,
Glossary, Bibliography

X Flare forecasts are daily probabilistic forecasts, ranging from 1% (0.01) to 99% (0.99), of the likelihood of an X class X-ray flare occurring within the specified 24-hour day. The X1 X-ray flare threshold is 10-4 Watts / m2 X-ray flux in the 0.1 to 0.8 nm passband as measured by the NOAA GOES spacecraft. Forecast lead times range from one to three days. Verification results are provided on forecasts from July 1986 (the beginning of solar cycle 22) through December 2013.


Stats Table Thumbnail Statistics Summary Tables

Observations Thumbnail Forecast Reliability Plot

Stack Plot Forecast Mean Error, RMS Error, and Linear Association Plot

Skill Plot Mean Forecast (event), Mean Forecast (no event), and Skill Plot

Forecast Skill vs Lead Time Forecast Skill vs Lead Time