Geomagnetic storm possible 2011/Feb/17 - further major flares possible from 1115

[Ulrich Rieth]

Hi all!

Actice region 11158 unleashed a major X2.2-solar flare with a 1300sfu Tenflare and a fast full halo CME earlier today.
It also had some major flaring yesterday with some halo CME as well.
Todays CME might impact earth magnetosphere tomorrow and trigger a major geomagnetic storm, if the solar wind parameters are good for such a scenario.
More infos from the profesional analysts shoul flow in later today.
Keep an eye on the sky during the coming night, because some of the earlier CMEs might produce auroral displays as well.
This could become the first major auroral storm in solar cycle 24 and you can be part of it.
Clear skies!

 Ulrich

[Ulrich Rieth]

Hi all!

The CME from tuesdays X-class solar flare has not yet impacted earth magnetosphere.
But it can only be a couple of hours away.
At this time we can expect still solar wind velocities of 500 to 600 km/s after impact.
Together with a good particle density this could be enough for a nice auroral display.
But only if the interplanetary magnetic fields (IMF) are oriented in a favorable southward way.
This will be known only after the impact.
So check back to the forum for an impact alert.
Clear skies!

 Ulrich

[Ulrich Rieth]

A CME related shockfront from the latest high solar activity in active region 11158 has impacted ACE satellite at arround 00:40 UTC on Feb 18th.
With initally strong northward tilted interplanetary magnetic fields, the geomagnetic effects are currently mild.
As this is a head on impact, earth might pass through the magnetic cloud of the CME.
During this passage the IMF orientation should slowly rotate towards a southward direction, thus increasing the geomagnetic effects.
Major to possibly severe geomagnetic and auroral storming seems to be possible today, Feb 18th.
As active region 11158 produced a couple of energetic flares and corellated coronal mass ejections during this week, further shock fronts in the solar wind maybe enroute towards earth.
If other shocks hit, even further intensification of the geomagnetic storm is possible.
Stay tuned for updates.

[Ulrich Rieth]

As the IMF strength is going down (below 10nT already), mid latitude auroral activity seems no longer possible.
High latitudes should still see some nice substorms due to the high solar wind speed.
Anyway, keep an eye on the solar wind data for some more hours.
Clear skies!

 Ulrich