As expected, an interplanetary shock wave associated with the "double CME" of June 13-14 hit Earth's magnetic field today around 09:57 UTC.
ACE Spacecraft detected an incoming shock passage around 09:00 UTC this morning and a Geomagnetic Sudden Impulse was recorded by the Boulder, Colorado magnetometer at 09:57 UTC. The solar wind speed in the wake of the CME barely upticked to 400 km/s, and the impact did not trigger a geomagnetic storm.
Right now geomagnetic activity is moderate, reaching G2 geomagnetic storming level (Kp=6) and we have S1 solar radiation level.
G2 level means that high-latitude power systems may experience voltage alarms, long-duration storms may cause transformer damage. Corrective actions to orientation may be required by ground control and changes in drag affect orbit predictions are possible. HF radio propagation can fade at higher latitudes. S1 level of solar radiation means that minor impacts on HF radio in the polar regions are possible.
Range 1 (minor) to 5 (extreme)
|Geomagnetic Storms *|
|Solar Radiation Storms|
S5 - Extreme
S4 - Severe
S3 - Strong
S2 - Moderate
S1 - Minor
The initial 18:00 UTC predicted time of the CME arrival has passed and the Solar Wind remains near 400 km/s. The weak incoming shock from early Saturday morning is most likely the one generated by the M1.9 event on June 14.
Sunspot AR1504 has developed a 'beta-gamma-delta' magnetic field that harbors energy for strong solar flares--and the huge sunspot is directly facing Earth. NOAA forecasters estimate a 65% chance of M-flares and a 5% chance of X-flares from AR1504 during the next 24 hours. There are no large coronal holes on the Earthside of the sun.
Sunspot 1506 in the northern hemisphere looks to be fading away and 1507-1508 remains stable. Elsewhere, new region 1509 was numbered on Friday and is a small alpha sunspot located in the southern hemisphere.