Coronal Mass Ejections (CMEs) from June 18, 19 and 21 have significantly increased chances for G3-Strong geomagnetic storms on June 22, 2015.
Two of the three CMEs were produced by Region 2371, one of the biggest regions of the current solar cycle, which is currently directly facing Earth. This region has 'beta-gamma-delta' magnetic configuration and is capable of producing more strong to major eruptions on Sun. Due to its location, CMEs this region could produce over the coming days would most likely be Earth-directed.
Full-halo CME produced by a long duration M3.0 solar flare which erupted at 17:35 UTC on June 18 hit our planet at 16:50 UTC on June 21. It was a glancing blow followed by the arrival of partial-halo CME (produced by filament eruption in the SSE quadrant early June 19) at 05:45 UTC on June 22.
Direct hit by full-halo CME produced early June 21 is expected around noon on June 22.
This CME is expected to catch up with the two observed on June 18 and 19 bringing them all to Earth in close succession by the UTC day of June 22.
A G3-Strong Geomagnetic Storm Watch has been issued for June 22 as well as a G2-Moderate Watch for June 23 as the CMEs make their way past Earth.
Area of impact is primarily poleward of 50 degrees Geomagnetic Latitude.
Under G3 conditions power system voltage irregularities are possible, false alarms may be triggered on some protection devices. Spacecraft systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur. Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur. HF (high frequency) radio may be intermittent.
Aurora may be seen as low as Pennsylvania to Iowa to Oregon.
WSA-Enlil CME model run at 15:23 UTC on June 21, 2015. Annotation: TW.
Space Weather Message Code: WATA50
Serial Number: 53
Issue Time: 2015 Jun 21 1714 UTC
WATCH: Geomagnetic Storm Category G3 Predicted
Highest Storm Level Predicted by Day:
Jun 22: G3 (Strong) Jun 23: G2 (Moderate) Jun 24: None (Below G1)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.
Solar radiation storm in progress
The greater than 2 MeV electron flux was at moderate to high levels with a peak flux of 1,880 pfu at 16:40 UTC on June 21. The greater than 10 MeV proton flux became enhanced in reaction to the M1 flare produced at 18:20 UTC on June 21 from Region 2367 and exceeded the S1 (Minor) threshold at 21:35 UTC.
S2 (Moderate) radiation storm threshold was reached at 03:50 UTC on June 22. According to NOAA, there are about 25 such events per one solar cycle (11 years).
Space Weather Message Code: ALTPX2
Serial Number: 58
Issue Time: 2015 Jun 22 0417 UTC
ALERT: Proton Event 10MeV Integral Flux exceeded 100pfu
Begin Time: 2015 Jun 22 0350 UTC
NOAA Scale: S2 - Moderate
Potential Impacts: Radiation - Passengers and crew in high latitude, high altitude flights may experience small, increased radiation exposures.
Spacecraft - Infrequent single-event upsets to satellites are possible.
Radio - Small effects on polar HF (high frequency) propagation resulting in fades at lower frequencies.
At 00:30 UTC today, SWPC said the greater than 2 MeV electron flux is expected to decrease to normal to moderate levels with the arrival of multiple CMEs on June 22 and remain at those levels over the next three days.
The greater than 10 MeV proton flux is expected to be above S1-Minor levels on June 22 and 23 due to effects from the M1 event from Region 2367.
Further enhancement is expected with the arrival of a combination of CMEs and flux will likely remain elevated into June 24 due to this activity.
Solar wind parameters are expected to remain slightly disturbed early on June 22 and then are expected to show further enhancement by midday and into June 23, reflecting the arrival of the combination of the 18, 19, and 21 Jun CMEs. Solar wind parameters are expected to show some recovery from CME activity on June 24.
G1-Minor to G3-Strong geomagnetic storm conditions are expected during the latter half of the day, followed by G1-Minor to G2-Moderate geomagnetic storm conditions on June 23 as the CMEs make their way past Earth. Unsettled to active conditions are expected on June 24 as CME effects subside.
Solar activity is expected to be at moderate levels (R1-R2, Minor-Moderate) throughout June 22 - 24 with a slight chance for an isolated X-class (R3-Strong) event.
Sunspots on June 22, 2015. Image credit: NASA SDO/HMI.
Featured image: WSA-Enlil CME model run June 21, 2015. Image credit: NOAA/SWPC. Annotation: TW.