Tag Archives: CME

Slow moving CME from Filament Eruption may arrive at Earth Jan 18

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On January 14, a filament eruption on the south-center earth-facing disk launched what appears to be a slow moving Coronal Mass Ejection. Estimated velocity of the CME indicate it may take as much as 4 to 4.5 days before it arrives at Earth. When it does, it’s possible there will be elevated KP. Due to the slow speed of the the CME, it is unlikely that it will produce significant aurora, but it could increase the KP to the highest it has been since the January 5th aurora.

Here’s an animated GIF of the solar storm launching. This eruption was so slow, that we had to speed up the images to four times the normal speed we show solar events

Slow moving CME launches from filament in the south-center Solar disk on 1/14
Slow moving CME launches from filament in the south-center Solar disk on 1/14

Happy Hunting

Brief G2 Aurora Storm Expected Tonight – January 3

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Update 22:00UTC January 3, 2016

It appears this #CME missed Earth and we won’t be getting an Aurora show tonight. From the beginning this was low confidence forecast. The CME’s signature was well South and West of the Earth-Sun line. If it was just a bit farther to the South or West, Earth would be untouched by the shock. It seems is what has happened. There is a slim, outside chance that it may still arrive, but with each passing hour it is less likely. Here is the output from the SWPC ENLIL model (How to read the ENLIL model) showing the predicted location of the CME:

ENLIL model shows the CME mostly South and West of Earth
ENLIL model shows the CME mostly South and West of Earth

Original Post: 03:00UTC January 3, 2016

Northern Lights Now – SWPC has issued a G2 geomagnetic storm watch for Sunday, January 3rd. Space weather forecasters are expecting a brief but strong storm as the Coronal Mass Ejection (CME) from a long duration solar flare passes Earth. It is expected to be a glancing blow as the plasma in the CME will pass mostly to the West and South of Earth. The predicted time of arrival of this fast moving CME:

Auroracast from NLN show the SWPC forecast of G2 storming from 4am to 10AM EST
Auroracast from NLN show the SWPC forecast of G2 storming from 4am to 10AM EST

What to expect:
As the edge of the plasma cloud passes Earth, proton levels will continue to rise as displayed on the EPAM. When the shock hits, they will jump then fall. About an hour later, magnetometers on Earth will register the passage of the shock. At that time, if the Bz component is south, there may be a short period of strong aurora. This CME is predicted to be mostly South and West of Earth, and could easily be too far away from Earth to make an impact as it passes, so this is a lower-than-normal confidence forecast.

This is the flare that produced the CME:

Animated GIF of the flare that cause the CME approaching Earth
Animated GIF of the flare that cause the CME approaching Earth

If you are planning on going out hunting tonight, remember to dress warmly. When you are standing still outside at night, you should dress for weather at least 20 degree colder than what is on the thermometer. Here’s a handy last minute guide to hunting aurora.

Stay tuned next week as coronal hole #44 may prompt SWPC to issue a new geomagnetic storm watch for January 5th and/or 6th.

Coronal hole rotating into the Earth Strike zone may prompt a new geomagnetic storm watch later this week
Coronal hole rotating into the Earth Strike zone may prompt a new geomagnetic storm watch later this week

Happy Hunting.

New Year’s 2016 Aurora Predicted – G3 Storming

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UPDATE: 20:00UTC December 31

The New Year’s Aurora of 2016 is playing out as expected in the “slower CME, longer storm” forecast scenario. There have been a few periods of G1-G2 storming. Wing-KP was overestimating the Kp and calling for 7+ earlier in the day. About 2 hours ago, Bz shifted strongly to the south and it has been in the -15nT to -17nT range since. It’s likely that the Wing-Kp model is now underestimating the actual extend of the aurora. The next 1-4 hours could produce some very good aurora. It even look likes there may be some clearing around sunset for downeast Maine, if the storm lasts another 6 hours, the upper Midwest may see northern lights around sunset as well

Some areas of clearing around sunset on the East Coast - might be able to see Aurora
Some areas of clearing around sunset on the East Coast – might be able to see Aurora

UPDATE: 04:00UTC December 31

The CME arrived! It arrived shortly after the previous update. so far Solar wind speed have been in the 425-475 km/s range, which is fairly low for a CME. The Bz component of the magnetic field has switched a couple times between negative and positive. There was a 45 minute period of sustained south orientation that pushed the KP to 5, but it has since subsided. It’s likely there will be more periods of high KP over the coming hours. Here’s is what the ACE data looked at at the moment the CME first arrived:

Bt Measured at the ACE satellite when the interplanetary shock hit.
Bt Measured at the ACE satellite when the interplanetary shock hit.

There are a lot of articles being posted about the ongoing storm. NLN has started a live updated post that contains links to those articles.

UPDATE: 00:00UTC December 31
8 hours after the official forecasted arrival of the CME, it hasn’t arrived yet. Not to worry, it is still on it’s way.

As noted in the original post, this means that it’s more likely the NASA Enlil model is closer to correct than the SWPC model. That means a wider, slower moving CME. It will bring a slightly weaker storm with slower solar wind speeds, but it also should make for a longer duration storm. This will give aurora hunters on the west coast and in Australia/NewZealand a better chance. If the storm lasts long enough, some new year’s revelers in Europe, Iceland and the East coast of the United states could be ringing in the new year under a dancing sky. Here’s the updated forecast graphic from SWPC:

Updated SWPC forecast shows G3 aurora extended to 12/31 and G1 into the new year
Updated SWPC forecast shows G3 aurora extended to 12/31 and G1 into the new year

UPDATE: 03:00UTC December 30

As the watch period begins, SWPC has updated the storm watch to G3. This means that KP=7+ is expected. There have only been a couple storms of this magnitude during this solar cycle. The timing of the start of the storm has stayed the same, roughly around 3pm UTC (10:00am EST). The duration prediction was extended to 15 hours, which should give north american viewers a better chance of seeing northern lights.

Three-day auroracast featuring day 1 with G3 storming predicted.
Three-day auroracast featuring day 1 with G3 storming predicted.

EPAM will continue to rise as the CME approaches Earth. Once the shock hits, EPAM should spike up, then start to decline. When the CME arrives at the ACE satellite, watch the Bz, if it is negative, this storm could be really good. If the Bz stays positive, this storm could top out at just KP=5, so keep your fingers crossed.

3-day EPAM graph shows a rise in electrons and protons measured at ACE as the CME approaches
3-day EPAM graph shows a rise in electrons and protons measured at ACE as the CME approaches

Also keep an eye on the arrival time of the CME. The later it arrives the weaker the storm will be, but the longer it will last (because the CME was moving slower than expected.

Original Post: 06:00UTC December 29

The Earth-directed Coronal Mass Ejection (CME) from Monday’s long duration solar flare is predicted to arrive on December 20. The Space Weather Prediction Center has issued a G2 geomagnetic storm watch for Wednesday and a G1 watch for Thursday. Aurora hunters with clear skies should get a nice show. For clouded-in skywatchers, keep an eye on the NLN Twitter feed for images of the northern lights.

Monday’s M1.86 originated from active region 2473 (Beta-Delta), the same region that produced a couple M-class flares as it rotated onto the disk about a week ago. The region was beyond the center of the Earth-strike zone during for this eruption, but was close enough for a nice CME signature on LASCO. In the CACTus image below, see the partial halo ejection:

Animated GIF from CACTus shows the partial halo CME signature from the 12/28 solar flare
Animated GIF from CACTus shows the partial halo CME signature from the 12/28 solar flare

The two main models that are used to predict the timelines of the storm are in disagreement. The official forecast model shows a stronger faster moving storm arriving around noon eastern time and lasting 6-12 hours. The NASA model shows a slower moving storm, that would be weaker, arrive later and last longer. It will be exciting to see which model proves correct. Here is the current predicted timeline for the KP according to the SWPC models.

Days Two and Three of the official max KP forecast from SWPC
Days Two and Three of the official max KP forecast from SWPC

NLN will continue to post updates on the twitter feed as this storm progresses.

Happy Hunting!