NOAA Logo

NWS Logo

Organizations

Space Weather Prediction Center

National Oceanic and Atmospheric Administration

Wednesday, July 30, 2025 05:50:12 UTC

Main menu

NOAA Scales mini

R1 (Minor) Radio Blackout Impacts
close
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

G1-Minor Geomagnetic Storms Observed

G1-Minor Geomagnetic Storms Observed
published: Wednesday, July 20, 2016 20:54 UTC

An interplanetary shock was observed at the ACE spacecraft at approximately 19/2310 UTC (07:10 PM Eastern). A geomagnetic sudden impulse was subsequently recorded at magnetometer sites around the globe at 19/2355 UTC (07:55 PM Eastern). G1-Minor geomagnetic storm conditions have been observed and G2-Moderate conditions are expected as a result of this CME arrival.