Thank Dog it's Friday

[altivo]

Not that the weekend looks relaxing as I'd like, but at least it's not work. Sorta.

Gary had a farmers' market gig to play today. Yesterday the weather forecast said 30% chance of rain, which he considered acceptable. This morning it said 80% chance of thundershowers. Of course, both were wrong. There was not a drop of rain in either Marengo or Harvard today. They were still saying 80% chance tomorrow as well, up to mid-afternoon. Now no rain for tomorrow (when he has another farmers' market.) How much do we want to bet he gets rained on? ;p

Auroras are flaring in northern EU tonight, so if you have clear skies in North America and especially if you live north of 47 latitude or so, it's worth checking out around your midnight local time.

The local apple orchards open this weekend. Guess where I'm planning to go. And no, not for the doughnuts.

Comments

[hrrunka]

Weather here's being a mite unpredictable, too. The forecast says it'll stay dry til the evening, but I think the humidity's a bit high for that. The cloud went from horizon to horizon yesterday evening, so no views of aurora here, even if it did get this far south.

[altivo]

We had clouds, but no rain. May clear for tonight. There are some great photos of last night's display at spaceweather.com.

[hrrunka]

Very bright displays up near Tromso. I expect Scotland may get to see something if the skies clear, but doesn't look as if i'll stretch this far south.

[altivo]

Last night's aurora was reported visible as far down as Michigan and Minnesota over North America. It was cloudy here, alas. One and possibly two more CME impacts are expected, though, and that would reinforce and possibly amplify the storm effect. Don't give it up yet.

[hrrunka]

I suspect the eight-eights cloud will do for my chances. My geomagnetic latitude is around 48 degrees, though, so very few aurora get this far.

[altivo]

Good point, I forgot that magnetic latitudes run lower on that side of the Atlantic. We have some advantage here in that respect.

[hrrunka]

Indeed you do. ;)

Compare http://www.swpc.noaa.gov/Aurora/globeNW.html with http://www.swpc.noaa.gov/Aurora/globeNE.html

[altivo]

Thanks. Those are useful maps and I tend to forget they exist. It looks as if you'd need an 8+ on the planetary K index while a 7 should be sufficient here. (Provided of course that the sky is clear, it is actually night time, and the moon isn't in the way.)

At this moment spaceweather.com reports the index at 4 with a peak of 5 in the last 24 hours. Not good enough, Mother Nature. Give us another little push, OK?

[avon_deer]

Should I be able to see them from where I am? I am 53 N

[altivo]

Judging by the chart at spaceweather.com, there may have been a chance there last night. There are photos now showing that the display was exceptionally brilliant farther north.

You may have issues with light pollution where you live, though. And you need to get to a clear view of the northern horizon. Also the moon is close to full, which could interfere.

They predict the display will continue for another day or more.

[avon_deer]

I was out last night, but sadly did not see a thing. I think perhaps you were right about the light pollution thing. I live in the middle of the West Yorkshire urban area. Luckily one does not have to drive far before the blackness of the Dales helps out.

[altivo]

Check the links hrrunka gives above. Click the map at your location to get your geomagnetic latitude. Unfortunately, in England the geomagnetic latitude is lower than the geographic one. Where I am the geomagnetic is higher, making the odds of aurora visibility better here than they are in Europe at the same geographic latitude. My estimate from the maps is that you'd want a planetary K index of 8 or more to give good odds of visible aurora at Wakefield.

Where I am, a 7 is probably good enough. Yesterday's peak value was only 5, though. As I write this, a value of 4 is reported. At least two more CME impacts are expected in the next day or two, and that could still push the index quite a bit higher.

Alas, it was clear most of the day here but clouds are rolling in again now.

[avon_deer]

Unfortunate.

[altivo]

Here's an easier predictor.

Use that link to see a three day planetary K index forecast. When the value hits 8 or higher, that's when to look for aurora in your area I think.

Here we can start looking at 7, but that peak came in the middle of the afternoon yesterday. Boo. The spectacular photos at spaceweather.com keep me hoping, though.

I have seen aurora before, both here and when I lived in Michigan. This far south it is usually pink rather than green and you do need a good clear and dark sky to see it.