S1 (Minor) Solar Radiation Storms are in progress but beginning to show signs of recovery. The greater than 10 MeV threshold of 10 pfu was reached at 0550 UTC (1:50 am ET) on 29 October 2015. Additionally, a warning was issued for the 100 MeV proton flux at or above 1 pfu and was valid from 29/0445 UTC until 29/1400 UTC. The alert threshold of 1 pfu was reached at 29/0435 UTC but 100 MeV levels have since dropped below 1 pfu and the warning has expired. This activity is a result of a coronal mass ejection (CME) that occurred from just beyond the SW limb of the Sun at around 29/0219 UTC; as noted by radio signatures known as Type II and Type IV sweeps. 10 MeV Proton levels are expected to fall below threshold shortly and, outside of another back-sided event, return to background conditions over the next 24 hours. Stay tuned for updates!
NOAA Scales mini
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.
UPDATE: S1 Solar Radiation Storm In Progress But Trending Down
UPDATE: S1 Solar Radiation Storm In Progress But Trending Down