Space Weather Message Code: WARK04
Serial Number: 2157
Issue Time: 2013 Aug 21 1236 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 2156
Valid From: 2013 Aug 21 0215 UTC
Now Valid Until: 2013 Aug 21 1600 UTC
Warning Condition: Persistence
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.
[link to www.swpc.noaa.gov]

SOHO Shock-plot for CME arrival:

[link to umtof.umd.edu]

Geomagnetic K- Indices:

[link to www.swpc.noaa.gov]

ACE MAG-SWEPAM:

[link to www.swpc.noaa.gov]