Moderate solar activity has been observed during the past 24 hours. M2.3 solar flare was triggered by an Active Region behind the eastern limb around 11:17 UTC. Three C flares occurred during the day producing two CMEs, observed by LASCO C2/C3 coming off the east limb early in the day, however neither are expected to be geoeffective.
Geomagnetic storming reaching the G2 (Moderate) level was observed overnight with the arrival of expected October 5 CME. At G2 level 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, HF radio propagation can fade at higher latitudes and changes are possible in drag affect orbit predictions.
The geomagnetic field began the period at unsettled levels before the arrival of the CME from 05 October around 04:45 UTC. At that time, a transient passage was observed at ACE and was then followed by a subsequent sudden impulse (21nT) to Earths magnetic field at 05:15 UTC. ACE observed a shock in the solar wind around 4:30 UT on October 8. The solar wind speed jumped from about 320 km/s to about 380 km/s, while the IMF jumped from 8 to 16 nT according to latest SIDC report. This shock signature is probably related to the CME from October 5.
Conditions increased to active levels before Minor geomagnetic storm (Kp = 6) level were registered. The geomagnetic field is forecast to be at minor storm levels (G1) on October 9 as the effect of CME continue. Quiet to active geomagnetic levels are possible on October 10, due to the possible influence of a recurring coronal hole that is expected to move into a potentially geoeffective position.
This event sparked wonderful aurora display for skywatchers as far south as Kansas, Utah and Colorado. Aurora watchers stay on alert for more bright auroras.
speed: 370.7 km/sec
density: 0.2 protons/cm3
The Radio Sun
10.7 cm flux: 98 sfu
Now: Kp= 4 unsettled
24-hr max: Kp= 6 storm
Interplanetary Mag. Field
Btotal: 16.3 nT
Bz: 13.9 nT south