Long-duration M8.1 solar flare produces strong Earth-directed CME, impact expected on June 1

This was a significant solar flare, associated with a Type II Radio Emission with an estimated velocity of 1 938 km/s, suggesting a coronal mass ejection (CME) was produced, and a 10cm Radio Burst (TenFlare) lasting 102 minutes and with peak flux of 1 100 sfu.

A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers, including radar, GPS, and satellite communications.

Additionally, a Type IV Radio Emission lasting nearly 5 hours was detected from 00:15 UTC to 05:08 UTC. Type IV emissions occur in association with major eruptions on the Sun and are typically associated with strong CMEs and solar radiation storms.

Model forecasts indicate an impact on Earth on June 1.

Radio emissions were forecast to be most degraded over the Pacific Ocean at the time of the flare.

“A slower storm ahead might cause a slight traffic delay, but G4 – Severe [geomagnetic storm] levels are possible by June 2,” space weather physicist Dr. Tamitha Skov said.

“This means aurora may be visible deep into mid-latitudes. Considering we expect big flares to continue on Earth’s dayside over the next few days, this means both the dayside and nightside radio bands will remain noisy, with periodic disruptions. Amateur radio operators, GPS/GNSS users like precision farmers, and aircraft/UAV pilots should plan accordingly.”

Update, 20:31 UTC on May 31

SWPC forecasters predict that geomagnetic storm conditions are likely to reach G4 – Severe levels on both June 1 and June 2, with a decrease to G2 – Moderate levels expected on June 3.