Geomagnetic storm in progress, subsiding solar radiation storm (May 24, 2013)
The geomagnetic storm associated with the May 22, 2013 solar flare (M5.0) and corresponding Coronal Mass Ejection (CME) is ongoing. G1 (Minor) geomagnetic storm conditions have occurred as a result. According to NOAA/SWPC, continued, low-level geomagnetic storming is expected over the next 24-36 hours as Earth remains under the influence of this disturbance.
The ACE Spacecraft first detected the shock passage at 17:35 UTC, followed by a geomagnetic sudden impulse measuring 18 nT at 18:12 UTC on May 24, 2013.
SUMMARY: Geomagnetic Sudden Impulse
Observed: 2013 May 24 1812 UTC
Deviation: 18 nT
ALERT: Geomagnetic K-index of 5
Threshold Reached: 2013 May 24 1853 UTC
Synoptic Period: 1800-2100 UTC
Active Warning: Yes
NOAA Scale: G1 - Minor
Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.
OVATION prime model Aurora forecast (Credit: NOAA/SWPC)
A solar radiation storm is still in progress around Earth, but is slowly subsiding. It currently ranks S1(minor) on NOAA storm scales, which means that minor impacts on HF radio in the polar regions could be possible. On May 23, 2013 Solar radiation storm reached S3 (Strong) levels at approximately 03:00 UTC. Proton levels continue to slowly decline. High-latitude sky watchers should be alert for bright auroras.
NOAA/SWPC satellite environmental plot with Global-D absortion map (Credit: NOAA/SWPC)
There are currently 5 numbered sunspots on visible solar disk. Sunspots 1755 and 1756 remain the largest visible sunspots with developed beta-gama magnetic configuration. Any eruption from these sunspots would be geoeffective. NOAA/SWPC forecasters estimate 45% chances of M-class and 15% chances of X-class events.
CURRENT CONDITIONS (May 24, 2013 - 21:06 UTC)
speed: 582.8 km/sec
density: 14.6 protons/cm3
The Radio Sun
10.7 cm flux: 135 sfu
Now: Kp= 5 storm
24-hr max: Kp= 5 storm
Interplanetary Mag. Field
Btotal: 13.4 nT
Bz: 10.1 nT north
LE and HE protons, Planetary Kp index, Global D Absorbtion levels and OVATION aurora forecast plots on May 24, 2013 around 19:00 UTC, just prior to CME shock passage. (Credit: NOAA/SWPC)
Featured image credit: OVATION Aurora forecast map North (Credit: NOAA/SWPC/OVATION)