NOAA Issues Geomagnetic Storm Warning - Scale G3 or Greater

Posted on August 5, 2011

NOAA has issued a Geomagnetic storm warning for a Geomagnetic K-index of 7 or greater expected. Reuters reports that U.S. power companies are preparing for possible distruptions. The warnings were triggered following a powerful solar flare, classified as an M9-class flare.

The warning messages from NOAA can be found here. Here is the latest warning message.

Space Weather Message Code: WARK07
Serial Number: 32
Issue Time: 2011 Aug 05 2146 UTC
WARNING: Geomagnetic K-index of 7 or greater expected
Valid From: 2011 Aug 05 2200 UTC
Valid To: 2011 Aug 06 0300 UTC
Warning Condition: Onset
NOAA Scale: G3 or greater - Strong to Extreme

The G3 level is listed as "strong" on the NOAA Space Weather Scale. The impact of a G3 level geomagnetic storm on power systems is described as: "voltage corrections may be required, false alarms triggered on some protection devices." You can see a chart showing the NOAA Space Weather Scale here.

SPACE