Is AR2891 active?

[Marcel de Bont]

52 minuten geleden, Tomasz Mielec zei:

Its look nice 

I think that model is way too optimistic, the SIDC expects an arrival late on 4 November and I agree with that. Perhaps even early 5 November. A G2 watch seems very likely, but lets see maybe NOAA goes with G3 again.

More info https://www.spaceweatherlive.com/en/news/view/449/20211102-m1-7-solar-flare-with-earth-directed-cme.html

[Drax Spacex]

4 hours ago, Jesterface23 said:

I'm thinking the end of the 4th as well. The shape of the CME isn't tricking me this time. It looks like another side impact or in between, so close to being a direct hit.

This is not an easy analysis.  I'd like to see some model based on photogrammetry that combines the images from LASCO and Stereo A coronographs identifying and tracking features, and provides as output a 3D point cloud animation of the CME.

Even with a halo or partial halo eruption, the CME pattern is not like a uniform spherical sector coming at us.  The pattern is complex with peaks, dips, and nulls.   We can't be sure exactly what the intensity of the CME will be in our tiny little sector of that halo.  The angular diameter of the Earth as viewed from the sun is only 0.0054°.

The data upon which these prediction models are based are high resolution imagery at the source (the Sun), but when considered at the destination (the Earth), it is actually very low resolution data.  While the models may be making best use of available information, given the coarseness of that data by the time it arrives at his destination, model uncertainty should always be expected.

[MinYoongi]

1 hour ago, Marcel de Bont said:

I think that model is way too optimistic, the SIDC expects an arrival late on 4 November and I agree with that. Perhaps even early 5 November. A G2 watch seems very likely, but lets see maybe NOAA goes with G3 again.

More info https://www.spaceweatherlive.com/en/news/view/449/20211102-m1-7-solar-flare-with-earth-directed-cme.html

 Do you think this run is plausible? Wouldnt this be very early?

[Tillson]

1 minute ago, MinYoongi said:

 Do you think this run is plausible? Wouldnt this be very early?

Oh wow, also how fast is ~1150km/h or ~1350km/h compared to "normal" storms? Would that make them more violent even if it's "just" a M1.7?

[MinYoongi]

1 minute ago, Tillson said:

Oh wow, also how fast is ~1150km/h or ~1350km/h compared to "normal" storms? Would that make them more violent even if it's "just" a M1.7?

Also very interested in this.

[Vancanneyt Sander]

51 minuten geleden, Tillson zei:

Oh wow, also how fast is ~1150km/h or ~1350km/h compared to "normal" storms? Would that make them more violent even if it's "just" a M1.7?

A takeoff speed of of thousand kilometres per second (NOT per hour) is pretty common. We even had CME’s with a speed of 2000km/sec but those are rare. See our help article about “how to know if a CME is headed towards Earth and when it will arrive”. We have a table there with the speeds and estimated arrival time.

And again, this event is a school example that strong solar flares doesn’t necessarily mean that those result in the strongest storms. As we’ve seen today a very long duration event can be enough to produce a strong storm. But very fast CME’s do have a bigger impact (with an impact speed of +700km/sec at arrival), less strong flares (M) don’t tend to have very fast CME’s

SIDC is in for a late arrival, other forecasters are more optimistic with a faster arrival like the one in that tweet. So yet again it will be a waiting game to see who’s had the best forecast. So don’t pin yourself on an arrival time!

[MinYoongi]

1 minute ago, Vancanneyt Sander said:

A takeoff speed of of thousand kilometres per second (NOT per hour) is pretty common. We even had CME’s with a speed of 2000km/sec but those are rare. See our help article about “how to know if a CME is headed towards Earth and when it will arrive”. We have a table there with the speeds and estimated arrival time.

And again, this event is a school example that strong solar flares doesn’t necessarily mean that those result in the strongest storms. As we’ve seen today a very long duration event can be enough to produce a strong storm. 

SIDC is in for a late arrival, other forecasters are more optimistic with a faster arrival like the one in that tweet. So yet again it will be a waiting game to see who’s had the best forecast. So don’t pin yourself on an arrival time!

Amen!  

 

It also slows down a little bit on the way, i guess.

[Tomasz Mielec]

Yup always slows on the way, i remember on 2014 a CME have speed 3400km/s on erupt and when he come to Earth have 900km/s

[Vancanneyt Sander]

1 minuut geleden, MinYoongi zei:

Amen!  

 

It also slows down a little bit on the way, i guess.

CME’s always slow down, which is normal. But the higher the liftoff speed the higher the solar wind speed at Earth on impact. This one should have a leftover speed of about 550km/sec.

[Tomasz Mielec]

SWPC Predicted around 650km/s

[Sam Warfel]

16 minutes ago, Vancanneyt Sander said:

CME’s always slow down, which is normal. But the higher the liftoff speed the higher the solar wind speed at Earth on impact. This one should have a leftover speed of about 550km/sec.

Is 550 enough to spark G2 storms? It seems awfully slow to me.

(I know it depends on other factors like the density and IMF strength and direction ofc)

[Marcel de Bont]

I didn't take into account the possible glancing blow of yesterday's M class solar flare and perhaps with the coronal hole solar wind stream now the solar wind ahead of the CME is fairly fast so perhaps not that much to slow this M1.7 CME down. But on NOAA's model it seems today's CME will eat up yesterday's CME that will be interesting. I used the speed the SIDC came up with (650km/s) in the news article but perhaps NOAA came to a different conclusion with STEREO A imagery which wasn't available when the SIDC released their rapport. They might adjust their forecast but my feeling after all these years is that the SIDC has a better track record than NOAA has. I still think an impact on 3 November (tomorrow) is really unlikely.

14 minuten geleden, Orneno zei:

Is 550 enough to spark G2 storms? It seems awfully slow to me.

(I know it depends on other factors like the density and IMF strength and direction ofc)

It could if the Bz goes to like -20nT which is not impossible at all but would need to be for a prolonged period. The north-south direction of the IMF (Bz) is however always the surprise factor so lets see. But I have high hopes for this CME, it had a beautiful full halo outline.

[Sam Warfel]

1 hour ago, Marcel de Bont said:

It could if the Bz goes to like -20nT which is not impossible at all but would need to be for a prolonged period. The north-south direction of the IMF (Bz) is however always the surprise factor so lets see. But I have high hopes for this CME, it had a beautiful full halo outline.

Thanks! ❤️

 

Do strong flares (X-class, especially stronger X-class ones) have a higher chance of launching CMEs than the little ones? I.e. if we see an X2 class flare, can we say it is very likely to have a CME before we see LASCO? Or is still uncertain with larger flares like it is with M-class?

Edited November 2, 2021 by Orneno

[Tomasz Mielec]

16 minutes ago, Orneno said:

Thanks! ❤️

 

Do strong flares (X-class, especially stronger X-class ones) have a higher chance of launching CMEs than the little ones? I.e. if we see an X2 class flare, can we say it is very likely to have a CME before we see LASCO? Or is still uncertain with larger flares like it is with M-class?

It always depends of eruptive events its or not and when flare takes more time we have more chances for CME. Even a strong X flare can not created CME.

Edited November 2, 2021 by Tomasz Mielec

[MinYoongi]

1 hour ago, Orneno said:

Thanks! ❤️

 

Do strong flares (X-class, especially stronger X-class ones) have a higher chance of launching CMEs than the little ones? I.e. if we see an X2 class flare, can we say it is very likely to have a CME before we see LASCO? Or is still uncertain with larger flares like it is with M-class?

Yeah the chances of  denser/stronger/faster Ejecta is higher with big solar flares. But the longer, the more certain an event is eruptive  

[Jesterface23]

In the rush of the morning I mixed days doing different calculations. I had a travel time of 56.33 hours putting it at L1 at around 2021/11/04 10:10Z. Just for the correction post I had an estimated error -16/+6 Hours on it.

Edited November 2, 2021 by Jesterface23

[Sam Warfel]

Sad, SWPC just released storm watches for the coming CMEs, but only G1, even for the full-halo one... 😥

3 hours ago, MinYoongi said:

Yeah the chances of  denser/stronger/faster Ejecta is higher with big solar flares. But the longer, the more certain an event is eruptive  

Thanks!

[Dominic Cantin]

Hello , I'm new here but not on aurora chase ! Heres a site I find useful for impact prediction. An impact at 00H00 on november 4th would be perfect for me in Québec city . Canada  ( p.s: sory for my english , I usualy speak french )

https://kauai.ccmc.gsfc.nasa.gov/CMEscoreboard/ 

[Space pro]

Are there any chances if G3 geomagnetic storm could happen when the CMEs hit the Earth?

[Sirvegs]

I was wondering about all the activity on the coronagraph c3. Are any of those earth directed? Does this mean an active spot is about to rotate onto the disk?

[Marcel de Bont]

37 minuten geleden, Sirvegs zei:

I was wondering about all the activity on the coronagraph c3. Are any of those earth directed? Does this mean an active spot is about to rotate onto the disk?

Dont want to go off topic too much, you could make a new topic for this question but there are indeed some slow CMEs to be seen. Could be filament eruptions or something along those lines. Does not look earth-directed. There might be a region on the south-east limb. You can see the coronal loops.

1 uur geleden, Space pro zei:

Are there any chances if G3 geomagnetic storm could happen when the CMEs hit the Earth?

I would not say it is impossible but also not very likely. It is not the fastest CME ever so to speak and the north-south direction of the IMF (Bz) would be negative for a good while in order to get such storm conditions. Lets wait and see, NOAA issued a G2 watch now.

11 uren geleden, Dominic Cantin zei:

Hello , I'm new here but not on aurora chase ! Heres a site I find useful for impact prediction. An impact at 00H00 on november 4th would be perfect for me in Québec city . Canada  ( p.s: sory for my english , I usualy speak french )

https://kauai.ccmc.gsfc.nasa.gov/CMEscoreboard/ 

Welcome Dominic. I recognize you from Facebook or Twitter? I have seen your name somewhere haha. Yes, that is indeed a good source where people leave their predictions!

[Sam Warfel]

1 hour ago, Space pro said:

Are there any chances if G3 geomagnetic storm could happen when the CMEs hit the Earth?

There's a new ENIL model that shows the halo CME will sweep up the other two on its way.  This combination can enhance the effects, and could cause G2 storms when it arrives in the last hours of Nov 3, with the storms beginning in the first hours of Nov 4th (all in UTC).  G3 however seems unlikely.

check https://spaceweather.com for the details.

Edited November 3, 2021 by Orneno

[Archmonoth]

3 hours ago, Orneno said:

There's a new ENIL model that shows the halo CME will sweep up the other two on its way.  This combination can enhance the effects, and could cause G2 storms when it arrives in the last hours of Nov 3, with the storms beginning in the first hours of Nov 4th (all in UTC).  G3 however seems unlikely.

check https://spaceweather.com for the details.

Hopefully we get some of those pretty lights in the lower longitudes. 

[Tomasz Mielec]

 

Something is coming

[Sam Warfel]

14 minutes ago, Tomasz Mielec said:

 

Something is coming

Did a CME just hit DSCOVR??

I’m seeing big spike in several graphs 

Edited November 3, 2021 by Orneno