Sunspot #1302 CME Sept 26, 2011.

Courtesy Of NOAA NWS SWPC.

Here's an animation of the model SWPC used to accurately forecast the Coronal Mass Ejection's (CME) arrival. The model, known as WSA-Enlil shows a view from above the north poles of the Sun and Earth, with the Sun shown as a yellow circle and the Earth as a green circle. The animation shows where density is high (as in the CME) in the colors of red, white and black, and where density is low (as in the background solar wind) in colors of blue and green. The CME is the curved, high density structure that transits from the Sun to the Earth. From the animation, it is clear we missed the center of the CME.

2011-09-26 19:00   

The fast Coronal Mass Ejection (CME) that erupted from NOAA Active Region 1302 arrived this morning at 1237Z (8:37am Eastern Time).  It has kicked off moderate (G2) geomagnetic storms for low latitudes, but high latitudes are seeing severe (G4) levels of activity.  Aurora watchers in Asia and Europe are most favorably positioned for this event, though it may persist long enough for viewers in North America.  The bulk of the CME missed the Earth, meaning the storm intensity and duration are less than what they would have been in the case of a direct hit.  We are posting frequent updates on the SWPC Facebook page, which you can follow (here).

2011-09-27 17:33   Update on the September 26/27 Geomagnetic Storm

The Geomagnetic Storm that began yesterday is quieting down, though we aren’t quite back to quiet conditions yet.  High speed solar wind is coming in behind the Coronal Mass Ejection and these winds are keeping things slightly active on the space weather front.  The region on the Sun that produced this activity is in a favorable position to cause further problems, but it is starting to weaken.  It remains a threat, though diminishing.  Yesterday, there would have been problems with high accuracy GPS and there was a noted issue with the FAA’s Wide Area Augmentation System (WAAS), where the Vertical Error Limit was exceeded.  WAAS is used to provide high accuracy GPS in the areas around airports.  Much more information about this storm is available on the SWPC Facebook page.

The Truth Is Stranger Than Fiction!