What to expect during the geomagnetic storm from the X2.8 solar flare?

[Carrington45X]

How far down in the United States could the resulting Auroras (if any) of this X2.8 flare go? 

[Marcel de Bont]

10 minuten geleden, Carrington45X zei:

How far down in the United States could the resulting Auroras (if any) of this X2.8 flare go? 

Minor G1 to at most moderate G2 storm conditions are expected so the northern most United States during local night time.

https://www.spaceweatherlive.com/en/help/the-kp-index.html

[fly]

13 hours ago, Marcel de Bont said:

Minor G1 to at most moderate G2 storm conditions are expected so the northern most United States during local night time.

https://www.spaceweatherlive.com/en/help/the-kp-index.html

 

are you basin this to historical data or recent data?

[Marcel de Bont]

5 minuten geleden, fly zei:

are you basin this to historical data or recent data?

Based on previous experience with coronal mass ejections like this including factoring in this coronal mass ejection it's speed and trajectory. Keep in mind this CME is heading mostly towards the west (partial halo) so we do expect only a glancing blow. Maybe G2 is even stretching it.

The NOAA SWPC came with a post a little later stating they also expect G2 at most:
 

Highest Storm Level Predicted by Day:
Dec 16:  G2 (Moderate)   Dec 17:  G2 (Moderate) 

[fly]

was the ones seen in greece and texas also predicted to be at G2?

sorry for asking but i find its really hard to dig into old data in this site, really cant find anything 

[Marcel de Bont]

3 minuten geleden, fly zei:

was the ones seen in greece and texas also predicted to be at G2?

sorry for asking but i find its really hard to dig into old data in this site, really cant find anything 

Yeah I think that was also expected to be G2 at most but that storm turned out to be stronger than expected

[tniickck]

the storm, if hits like modeled on enlil is gonna be a strong G4, but due to flare's too west position it is hard to exactly prognose the storm level

[M42Sparks]

So when is the predicted impact timing of arrival?

[Philalethes]

4 minutes ago, M42Sparks said:

So when is the predicted impact timing of arrival?

Around 17Z according to Enlil, probably +/- a few hours of uncertainty.

[Snogers]

1 hour ago, Philalethes said:

Around 17Z according to Enlil, probably +/- a few hours of uncertainty.

17Z what time zone?

[tniickck]

11 minutes ago, Snogers said:

17Z what time zone?

UTC

 

[Philalethes]

12 minutes ago, Snogers said:

17Z what time zone?

The "Z" refers to "Zulu time", which is the same as UTC; it's just shorthand notation.

[MinYoongi]

4 hours ago, tniickck said:

the storm, if hits like modeled on enlil is gonna be a strong G4, but due to flare's too west position it is hard to exactly prognose the storm level

i found g4 nowhere, what are you basing this on? not even enlil/nasa enlil suggested G4 and no scientist on DONKI did. there was one model where the shock was modelled and the model gave out a kp5-8  but the scientist clarified how its to be interpret (linked in the other thread by me) 

[tniickck]

4 minutes ago, MinYoongi said:

i found g4 nowhere, what are you basing this on? not even enlil/nasa enlil suggested G4 and no scientist on DONKI did. there was one model where the shock was modelled and the model gave out a kp5-8  but the scientist clarified how its to be interpret (linked in the other thread by me) 

i am basing on density and speed. if bz stays south most of the time ofc, if it will be north we aint gonna hit even g1

[MinYoongi]

Just now, tniickck said:

i am basing on density and speed. if bz stays south most of the time ofc, if it will be north we aint gonna hit even g1

yeah but where are you getting the G4 from? 

and true about the northward component, thats something many people forget

[arjemma]

This will be a glancing blow. As @Marcel de Bont says most of the plasma is going west of earth. Media is painting it like it's a direct hit which it is not.

I would say that we can reach G3 if the bz field is predominantly southward but not otherwise. This isn't as big as many news outlet makes it sound like. 

[MinYoongi]

1 minute ago, arjemma said:

This will be a glancing blow. As @Marcel de Bont says most of the plasma is going west of earth. Media is painting it like it's a direct hit which it is not.

I would say that we can reach G3 if the bz field is predominantly southward but not otherwise. This isn't as big as many news outlet makes it sound like. 

i agree. i just found the quote by @tniickck in another topic as follows:

Quote

"If everything goes according to model, it will be a pretty strong Kp8. however there is not enough confidence cuz the flare was pretty far from central meridian and it can happen as Kp4 or as Kp8+ or even Kp9-"

and im sorry but i have to disagree, to me thats a bit utopian and i still wonder what data thats based on because i saw no one talk about G4 or even G5

Met space weather from the UK Gov: 

"The second CME arrival is likely to give G1-G2 Minor to Moderate storms (Kp5-6) early Day 2, with a slight chance of isolated G3/Strong storm intervals (Kp7)" seems on par with noaa and nasa here.

[arjemma]

6 minutes ago, MinYoongi said:

i agree. i just found the quote by @tniickck in another topic as follows:

and im sorry but i have to disagree, to me thats a bit utopian and i still wonder what data thats based on because i saw no one talk about G4 or even G5

Met space weather from the UK Gov: 

"The second CME arrival is likely to give G1-G2 Minor to Moderate storms (Kp5-6) early Day 2, with a slight chance of isolated G3/Strong storm intervals (Kp7)" seems on par with noaa and nasa here.

I totally agree with you. Sure it can reach high levels if the bz is very strongly southern but this is just blown out of proportions. I have seen several wather agencies predictions and I haven't seen kp 8 anywhere.

[tniickck]

38 minutes ago, MinYoongi said:

i agree. i just found the quote by @tniickck in another topic as follows:

and im sorry but i have to disagree, to me thats a bit utopian and i still wonder what data thats based on because i saw no one talk about G4 or even G5

Kp9- is not G5, if i remember correctly. 

and I don't really care what do agencies and NOAA say, just saying my own expectations. the humanity still doesnt have enough satellites and knowledge to predict everything very accurate, so we are left to "guess on the coffee grounds" 

[Vancanneyt Sander]

5 minuten geleden, tniickck zei:

Kp9- is not G5, if i remember correctly

True, still G4

Of all predictions a Kp of 3+ to 6- is expected. Many seem to forget that the strength of a solar flare isn’t in correlation with a storm strength, yes it was an X-class event but the CME was not as good as the previous storms we’ve had. 
we’ll know when it arrives, and as long as it hasn’t arrived it’s just speculations.

[Jesterface23]

It the CME arrives this afternoon UTC G3 would seem possible. Though if it manages to go through to tomorrow afternoon without an arrival, the expectations will probably gradually decline down to G1.

If only the region could of been just 30 degrees closer when the CME launched.

[MinYoongi]

Just now, Jesterface23 said:

It the CME arrives this afternoon UTC G3 would seem possible. Though if it manages to go through to tomorrow afternoon without an arrival, the expectations will probably gradually decline down to G1.

If only the region could of been just 30 degrees closer when the CME launched.

whats afternoon UTC for you? its already evening UTC  hehe. i think isaw a forecast for about 19 UTC, ? that would be in ~2h

[Jesterface23]

1 minute ago, MinYoongi said:

whats afternoon UTC for you? its already evening UTC  hehe. i think isaw a forecast for about 19 UTC, ? that would be in ~2h

It is half past 5pm UTC currently, so it is close enough lol. We are almost into the different forecasted times, but there hasn't even been a steep incline in SA's proton levels yet.

[Vancanneyt Sander]

EPAM isn’t yet above event level, so it ain’t close…

[Adrian Kobyłecki]

I guess it's already arrived