Saturday, February 16, 2013

SOLAR WATCH: Sudden Geomagnetic Impulse Results In Interplanetary Shock Wave - Arctic Alert For Auroras During The Disturbance!

February 16, 2013 - THE SUN - According to NOAA/Space Weather Prediction Center, although the Sun has been quiet for weeks, a sudden geomagnetic impulse is expected for February 16th, 2013.

Space Weather Message Code: WARSUD
Serial Number: 125
Issue Time: 2013 Feb 16 1145 UTC

WARNING: Geomagnetic Sudden Impulse expected
Valid From: 2013 Feb 16 1145 UTC
Valid To: 2013 Feb 16 1215 UTC
IP Shock Passage Observed: 2013 Feb 16 1058 UTC

Space Weather Message Code: SUMSUD
Serial Number: 167
Issue Time: 2013 Feb 16 1217 UTC

SUMMARY: Geomagnetic Sudden Impulse
Observed: 2013 Feb 16 1210 UTC
Deviation: 10 nT
Station: Boulder

NOAA Space Weather Scale descriptions can be found at - NOAA/SWPC.

INTERPLANETARY SHOCK WAVE: A shock wave moving through the solar wind hit Earth's magnetic field on Feb. 16th at approximately 11:30 UT. The impact did not spark a geomagnetic storm. Nevertheless, sky watchers around the Arctic should be alert for auroras as Earth passes through the wake of the disturbance. - Space Weather.

WEAK SHOCK DETECTED: The ACE Spacecraft detected a weak interplanetary shock at 10:58 UTC this morning. The solar wind increased to around 400km/s. A sudden geomagnetic impulse was detected by the Boulder, Colorado magnetometer at 12:10 UTC and measured 10nT. This signaled the passage of the weak shock past our planet. This particular event is not expected to bring widespread geomagnetic disturbances.

UPDATE: The Kp index is currently at 4, which falls just below minor geomagnetic storm levels. The solar wind remains near 400 km/s with Bz fluctuations from -11 nT to +7 nT. Visible aurora will be likely at very high latitudes.

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2013 Feb 16 1730 UTC
Synoptic Period: 1500-1800 UTC
Active Warning: Yes
Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

SUMMARY: Geomagnetic Sudden Impulse
Observed: 2013 Feb 16 1210 UTC
Deviation: 10 nT
Deviation: 10 nT
Station: Boulde - Solar Ham.

Updated image of the visible solar disk on Saturday morning. Sunspot 1671 and new Sunspot 1673 remain fairly stable. A small new sunspot is forming in the northeast quadrant, but is not yet a threat for strong solar flares. Elsewhere, another sunspot trailing region 1673 is now beginning to rotate onto the southeast limb. There will be a chance for isolated C-Class flares.

There are currently 5 numbered sunspot regions on the disk:

None of these sunspots is actively flaring. Credit: SDO/HMI.
Solar wind flowing from this sinuous coronal hole could reach Earth starting on Feb. 20th. Credit: SDO/AIA.

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