Earth-directed CME

[Rick]

"Among space weather forecasters, confidence is building that Earth's magnetic field will receive a double-blow from a pair of CMEs on Sept. 12th. The two storm clouds were propelled in our direction by explosions in the magnetic canopy of sunspot AR2158 on Sept. 9th and 10th, respectively. Strong geomagnetic storms are possible on Sept. 12th and 13th as a result of the consecutive impacts. Sky watchers, even those at mid-latitudes, should be alert for auroras in the nights ahead."

From http://spaceweather.com/

[Canadian Roger]

So...will we see aurora tonight?

To get the answer, we need to know two things:
1) Your geomagnetic latitude.  This is your latitude based not on the rotational pole of the earth, but of the magnetic pole.  London, for instance is at geographic 52 degrees north and geomagnetic 47 degrees, while Toronto is at 44 degrees and 54 degrees, respectively.

So, for the southern UK to see aurora, we'll need a severe to extreme geomagnetic storm.  This is a Kp index of 8-9,  whereas I need a 6-7. 

However, your mileage may vary.  Aurora are very dependant on light pollution.  If it's going to be clear tonight, then you may want to head for dark skies...preferably one without a light dome to the north.

For lots of good information: http://www.swpc.noaa.gov/Aurora/

Good luck!

[Rick]

Yep, we do very occasionally get aurorae this far geomagnetically south, but this event is unlikely to produce anything. Having London to our north doesn't help.

[Mike]

Petra and I are on the northern tip of the Isle of Skye on holiday. We are hoping to see something tonight but it's patchy clouds and there is a super bright moon so its not ideal. Fingers crossed.

[Carole]

Good luck Mike, nothing like being in the right place at the right time. 

Carole

[Mike]

Getting a faint green aurora here on Skye in the north. Showing up clearly on 10 second exposures but it's nothing exciting.

[Mike]

This was exciting as it got unfortunately. A faint green glow in the North.

[Rick]

The story still got Radio 4 interested enough to do a short report on Saturday afternoon. Wonder whether folks over the ocean saw anything more exciting?

[Carole]

That's a shame Mike.

Carole

[Rick]

Here'a an APOD taken last Friday night from North America.

[Carole]

Stunning.

Carole

[MarkS]

Good effort Mike - at least you caught something!

Mark