NOAA / Space Weather Prediction Center

S1 Proton Event Forecast Verification

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S1 Proton Event forecasts are daily probabilistic forecasts, ranging from 1% (0.01) to 99% (0.99), of the likelihood of a S1 Proton Event occurring within the specified 24-hour day. The event threshold proton flux is 10 pfu (particle flux units = particles / cm2-s-sr) at greater than 10 MeV 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.

The proton event forecast was fundamentally changed in Jan 2000. Prior to this date the forecast was for the likelihood (probability) of the >10 MeV proton flux passing the 10 pfu event threshold (event onset). Events already in progress were not counted as events on subsequent days. In Jan 2000 the forecast was changed to be the likelihood that the >10 MeV proton flux would be above the 10 pfu event threshold on a given day. Thus events lasting several days after Jan 2000 constitute proton events on each of the days the event threshold is exceeded, not just on the day of event onset as before Jan 2000.


Stats Table Thumbnail Statistics Summary Tables

Observations Thumbnail Forecast Reliability Plot

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

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

Forecast Skill vs Lead Time Plot Forecast Skill vs Lead Time