Tag Archives: G2

Big Halloween Aurora Expected October 30, 2021

Northern Lights Now – A large x-class flare released a CME towards Earth on October 28, 2021. The CME is expected to arrive at Earth Midday Oct 30 GMT. SWPC has issued a G3 storm watch. If the CME arrives with Bz south orientation, it’s likely to bring 24-36 hours of KP=6 and KP=7 storming.

G2 and G3 storming expected over Halloween weekend
G2 and G3 storming expected over Halloween weekend

Here’s a quick video of the flare that launched the CME

As the storm arrives, keep an eye on the Solar Wind data page. When the ICME hits, expect the solar wind speed to jump, and density and total Bt to increase. When the shock front arrives, watch the Bz closely. If it drops deeply negative, there is a very strong likelihood that there will be an aurora display. If the storm starts with a north (positive) orientation, aurora hunters will need to wait for the second phase of the arrival and the maximum potential level decreases to G2.

Happy Hunting!

Solar Storm arrives with ICME impact early on October 12 GMT (live updates)

Northern Lights Now – The expected ICME has arrived. In the first hour since it arrived, solar wind data is indicating that is is oriented favorably to put on an aurora show.

Update: 16:00 GMT Oct 12, 2021:

What an amazing storm! The third phase of the storm arrived around 9:30 and had a strong (-14nT) southward component. With the atmosphere already primed from the first phase of the storm, aurora activity quickly elevated. Aurora sighting reports rolled in from all across northern North America. NLN will be doing storm recap later, but for now, enjoy this timelapse that shows all three phases of the storm from skunkbayweather.com

Update: 08:00 GMT on Oct 12, 2021:

It appears the second part of the CME is arriving, and Bz orientation is variable. It’s likely this means the storm is over for now.

Update: 07:00 GMT on Oct 12, 2021:

This has been a terrific storm. There has been an extended (6 hours now) period of moderate activity. Aurora reports have been coming in on Twitter from Iceland, Canada, New England (as far south as southern New Hampshire), the mid-west US and now Washington State and Alaska. Geomagnetic activity has reached G2, KP=6, levels as predicted by the SWPC.

The show looks like it will continue. Bz just dropped strongly south, so there should be another sub-storm over the next hour or two. We are expecting there will be aurora reports streaming in from hunters in New Zealand and Tasmania next.

After the current sub-storm, expect the core of the CME to arrive at earth. It is still impossible to forecast the orientation of the core of this storm. It is about a 50/50 tossup that it is oriented south and there is another 6-9 hours of activity, or that it is oriented north and the aurora ends. Keep an eye on the data and the orientation should reveal itself soon.

Original Post:

The shock arrived at the DSCOVR satellite around 1:45am GMT on October 12, 2021. At the time of impact, Solar wind speed jumped from 350km/s to almost 500 km/s. Proton density and BT also jumped in synchrony. Bz is always the wildcard. It is hard to know how the B component will be oriented until it arrives. Tonight, it arrived with a strong negative orientation. This is the most favorable setup for producing aurora.

In the image below, the upper chart is a proxy for hemispheric power and can be seen on the DSCOVR solar wind page. The more bars and the longer the bars the higher the likelihood of aurora. As time goes on, if the favorable conditions persist, the bars will continue to grow. In the lower part of the image, you can see when the ICME shock arrived with the big jump in solar wind data.

Favorable conditions for aurora seen early on October 12, 2021
Favorable conditions for aurora seen early on October 12, 2021

Happy hunting

G1-G2 Aurora activity for Late September 2020

Northern Lights Now – Geomagnetic activity reached G2 storm levels on September 27 bringing stunning views of aurora to high latitude regions. The activity is the result of a coronal hole high speed stream and is expected to continue for the next three days.

NLN forecast shows periods of G1 and G2 activity each of the next three days
NLN forecast shows periods of G1 and G2 activity each of the next three days

Update 07:30 UTC 9/29/2020 03:00 EDT

Geomagnetic activity reached G1 levels occasionally this evening as predicted. Conditions have moderated and the aurora is much less active now. At the beginning of the period, solar wind speed were around 625 km/s. They have since decreased to around 575 km/s. The biggest factor in the decrease in activity is the Bz. Look at how variable it has been over the last 12 hours:

Bz has been variable over the last 6 hours.
Bz has been variable over the last 6 hours.

During the period of G2 storming, there was over 4 hours where Bz was sustained south. Any deviation into north (positive on the chart) puts an immediate damper on northern lights activity. The CH HSS is expected to remain geoeffective for the next 24-48 hours, it is very possible we could get another sustained period of south-oriented Bz. Keep an eye on the solar wind data!

Original Post

Solar wind speeds reached 640 km/s, the highest readings Since the beginning of August. The higher activity is associated with a Northern Hemisphere coronal hole. The coronal hole has a wide longitudinal opening – meaning that it will influence Earth’s magnetosphere for several consecutive days. In addition, the remains of AR 2773, shown below as a brighter area to the left, are just to the East of the CH and have the potential to inject higher wind speeds and density into the stream.

Late September 2020 coronal hole with the refinements of AR 2773 just to its east
Late September 2020 coronal hole with the refinements of AR 2773 just to its east

To know exact timing of the expected activity, keep and eye on the solar wind. Generally, the more bars there are on the chart, and the taller they are, the more likely there will be higher KP readings.