Geomagnetic Activity Forecasts
Background information on the GPRA metrics can be found in the PDF document SWPC GPRA Metric Description and the metric formula can be found in the Forecast Verification Glossary.
NOAA Scales mini
R1 (Minor) Radio Blackout Impacts
HF Radio: Weak or minor degradation of HF radio communication on sunlit side, occasional loss of radio contact.
Navigation: Low-frequency navigation signals degraded for brief intervals.
More about the NOAA Space Weather Scales
Navigation: Low-frequency navigation signals degraded for brief intervals.
