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:
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:
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:
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.
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
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:
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:
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.
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.
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:
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.
NLN will continue to post updates on the twitter feed as this storm progresses.
An amazing night of Aurora! It’s possible the two storms mentioned detailed in this post have merged together, producing a prolonged geomagnetic event. Storm levels have been at or above G1 (KP=5) for 15 hours. Bz has maintained a strong southward component. All signs point to another good night of aurora in northern Europe as far south as the Netherland and Germany. If you are planning to go out tonight, don’t forget the Last Minute Aurora Viewing Preparation Guide
UPDATE: 12/20/2015 1:30 AM EST
The Bz has shifted strongly south. Aurora reports are starting to come in. If the storms maintains it’s southward orientation, this is going to be a good storm.
UPDATE: 12/19/2015 10:40 PM EST
The CME has arrived at Earth. It arrived about 16 hours later than the earliest estimates. Now watch for the Bz orientation of the magnetic fields. If it stays negative, we could be in for an amazing show!
UPDATE: 12/18/2015 4:00 PM EST
EPAM is showing a clear rise in particles, the CME arrival is expected any moment now.
Two eruptions on the Sun have unleashed a coronal mass ejection (CME) towards Earth. When it arrives it is expected to induce a G2 geomagnetic storm with the potential for aurora displays at mid-latitudes. The predicted timing of the arrival is good for Europe and excellent for North America. If it arrives on schedule, space weather predictions often are accurate within 3-6 hours, the northern lights show should start in Europe just before midnight, and it will be active as the Sun sets in the United States and Canada. It should last 6+ hours once it begins.
Imaging satellites in space, both ACE and SOHO, captured wonderful clear images of the eruptions. The explosions are so clear that anyone viewing them can easily identify the location and duration. In the video montage below, each view of the sun is campured through cameras with different lenses. Each sequence is roughly 80 images from SDO stitched together as a timelapse. The first, red, shows the eruptions at the 304 angstrom wavelength, followed by 335 angstroms (blue) and then 211 angstroms (purple). In each sequence the first eruptions is dead center and is from a C6.69 flare. The second is an elongated eruption to the South and East.
When flares like this occur, sometimes they eject hot plasma into space in the form of a CME. The LASCO camera aboard SOHO (Solar and Heliospheric Observatory) satellite is a specialized tool with an arm and disk in front of the lens designed to block the light coming directly from the Sun. This enables the camera to view the CME as light reflects off of it as it travels into space.
Both eruptions in the video above generated CMEs. The video below shows the raw image of the sun through lasco on the left, and then a black and white image of the difference between each set of frames coming from the those frames. The differential image makes the size and shape of the CME apparent. When the CME is mostly in one direction it means the CME is off the Earth sun line, but when the CME appears on all sides of the Sun, as is the case in this video, it indicates the CME is headed straight towards Earth. Space weather scientists can measure the speed of the CME from these images and use that estimate to predict when the CME will arrive at Earth.
What to Expect:
As of writing, the forecast is for aurora activity to begin at 21:00GMT on December 18th (4:00pm EST), and to increase over the following 6-9 hours. The NLN 3-day auroracast clock is updated two times per day, visit it for the most up-to-date forecast.
As the CME approached Earth, the first signs it is approaching will be that the EPAM rises – this happens because the approaching plasma in the CME is radiating electrons and protons. Once it arrives, the solar wind speed, the Bt and proton density, this data is available at spaceweatherlive.com, will show a sudden increase. When that happens, watch the Bz – if it is negative aurora hunters are in for a good show. Also watch the live KP. This is the best metric there is for knowing when aurora may be visible, it offers a 40-70 minute forecast. The higher the KP is the lower latitude the aurora will be visible. Here is the NLN auroracast at the time of this post: