Late September 2016 Aurora Live Blog

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Northern Lights Now – A large coronal hole pointed towards earth means there may be many as 72 hours of G2 storming between September 28 and September 30. It is likely that during that time KP values will occasionally be above 5.67 and the aurora borealis will treat Aurora hunters to a show. Refresh this page often as we’ll be posting live updates as this storm impacts Earth.

Update #8: 47:00 hours in, 2300 UTC 9/29/2016 (07:00pm EST 9/29/2016)

Wrapping up the second full day of G2 storm watch, and the third day of active storming. Today there have been 4 periods of G1 storming recorded. There should be more G1-G2 storming over the next 24 hours with the possibility for some G3 if the Bz cooperates (which it hasn’t been doing much of so far this storm.

Update #7: 36:30 hours in, 1230 UTC 9/29/2016 (08:30am EST 9/29/2016)

Since the last update, there has been nearly consistent G1 storming. Pictures of aurora and proton acrs started rolling in on Twitter. Take a look at the 6 hours chart from NLN’s current KP page showing consistently KP5+

Consistenly KP5+ over the last 5-6 hours
Consistenly KP5+ over the last 5-6 hours

These two twitter post show proton arcs that happened overnight for this storm, one in Montana, the other was visible in the North Caithness coast

Update #6: 29:00 hours in, 0500 UTC 9/29/2016 (01:00am EST 9/29/2016)

Just a quick update. The negative Bz did infact lead to a small substorm. KP is back to G1 levels. Check out that same webcam now, it is showing much more green:

More northern lights visible on Sebec Lake webcam
More northern lights visible on Sebec Lake webcam

Update #6: 28:15 hours in, 0415 UTC 9/29/2016 (12:15am EST 9/29/2016)

On of the great things about the internet is that people hook up webcams and share them with the world. Check out www.sebeclake.net where you can watch aurora live when it’s cloudy where you are. Right now, it’s clear in Eastern Main and the webcam is showing some faint green on the horizon:

Sebec Lake webcam shows some aurora on the horizon
Sebec Lake webcam shows some aurora on the horizon

On that note, after it has been quiet for the last 3-4 hours, the Bz has been oriented negative for over 15 minutes now at a strength of more than -5Bz. This means there could be a small substorm coming in the next 30-60 minutes. Watch that KP!

Update #5: 26:00 hours in, 0200 UTC 9/29/2016 (10:00pm EST 9/28/2016)

About one third of the way through the predicted duration of the late September active period and so far the storm is mostly as expected. There have been 2 periods of G2 storming recorded so far and 7 periods of G1. Solar wind has continued to stay in the range of 600-725km/s.

Two G2 periods and Seven G1 periods over the last 48 hours.
Two G2 periods and Seven G1 periods over the last 48 hours.

Those strong KP readings are all the more impressive because Bz has been variable, rarely staying negative for more than about an hour. That indicates the long duration of strong solare wind as primed the magnetosphere for a big show if there is a period of negative Bz that lasts a couple hours. Here is the 24 hour view of solar wind data, note that Bz is continuously shifting between negative (south) and positive (south) orientation (click to see full size image):

24 hour solar wind data graph from SWPC shows Bz's orientation has been variable
24 hour solar wind data graph from SWPC shows Bz’s orientation has been variable

We have not seen a lot of great pictures from this storm so far. Lots of the traditional Aurora hot spots are clouded in. Hopefully it clears out for some of you over the next 48 hours. Please share your pictures with as at @northLightAlert on Twitter!

Update #4: 20:45 hours in, 2045 UTC 9/28/2016 (5:45pm EST 9/28/2016)

G2 storming is ongoing now!

G2 storming shortly
G2 storming shortly

Update #3: 11:00 hours in, 1100 UTC 9/28/2016 (7:00am EST 9/28/2016)

Activity has decreased a bit over the last 9 hours. One additional period of G1 storming was recorded since the last update, current KP estimates are between 3 and 4 which is not enough for most of our readers to have a chance of seeing a show.

In the lull, let’s take a quick look at NLN’s dynamic inforgraphic of DSCOVR solar wind data. The chart below shows the strength and duration of the wind. Generally, more taller bars mean a better chance of a higher KP. The height of bars indicate how long the solar wind has been favorably exceeded the threshold along the bottom. For example, below: wind speed has been above 400km/s for over 48 hours, above 500km/s for over 18 hours, and above 600 km/s for an hour. One of the most important factors for aurora is Bz, the value on the right of the chart, when it is negative and has been for more than an hour or two, that is some of the best time to go out on the hunt. The chart updates automatically – no need to refresh that page!

Current Snapshot of NLN's dynamic DSCOVR solar wind infographic
Current Snapshot of NLN’s dynamic DSCOVR solar wind infographic

Update #2: 3.5 hours in, 0330 UTC 9/28/2016 (11:30pm EST 9/27/2016)

The official G2 watch period has started. There has been G1 and G2 activity consistently over the previous 24 hours, even before the offical watch period begins. This has happened without Bz making a sustained southward shift. Solar wind exceeded 700km/s for about an hour just after midnight GMT. Any sustained period of south oriented Bz could make for a very strong aurora display.

In the 0030 SWPC aurora forecast discussion, there are a pair of notes that it is possible that storming could reach G3 levels over the next three days. This would mean KP values of 6.67 and above!

SWPC discussion indicates the possibility of G3 storming on Days 2 and 3
SWPC discussion indicates the possibility of G3 storming on Days 2 and 3

Update #2: t-2 hours, 2200 UTC (6:00pm EST) 9/27/2016

The storm is rolling! G2 storming levels we reached in the 6:00pm UTC hour. Solar wind speeds are now over 650km/s and there have been periods of south oriented Bz. Here’s the reported 3-hour KP values from SWPC:

First Period of G2 storming reached in the 6pm UTC reporting period
First Period of G2 storming reached in the 6pm UTC reporting period

Aurora reports are already streaming in! Check out these northern lights that happened just after sunset in Iceland:

Update #1: t-20 hours, 0400 UTC (midnight EST) 9/27/2016

SWPC increases duration of storm watch to 72 hours. Here are the updated timings of this G2 storming. It is important to note that these specific timings are less meaningful in a long duration event like this as it’s likely that the exact timing of KP spikes will depend on when substorms carried by the solar wind arrive at Earth.

AuroraCast for days 2 and 3 (Sept 28 and 29)
AuroraCast for days 2 and 3 (Sept 28 and 29)

SWPC Notifications timeline shows three days of potential G2 storming
SWPC Notifications timeline shows three days of potential G2 storming

G2 Aurora Predicted for Last Week In September

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UPDATE – 9/27/2016 03:30 GMT (11:30 EST on 9/26)

SWPC has issued a continuation of the G2 aurora watch through September 30. There are now 72 hours of potential G2 storming predicted. NLN is starting up what promises to be a long duration live-blog post. As of midnight GMT on 9/27 here’s the 2nd and 3rd day AuroraCast forecast showing expected times for G2 storming, and the updated notifications timeline from SWPC.

AuroraCast for days 2 and 3 (Sept 28 and 29)
AuroraCast for days 2 and 3 (Sept 28 and 29)
SWPC Notifications timeline shows three days of potential G2 storming
SWPC Notifications timeline shows three days of potential G2 storming

Excited for this week!
Happy Hunting

–Original post:

Northern Lights Now – The return of a large coronal hole means the final week of September could be very good for aurora viewers. The Space Weather Prediction Center (SWPC) in Boulder, Colorado has issued a G2 geomagnetic storm watch for Wednesday September 28, when high speed solar wind from the coronal hole is expected to reach Earth. The watch means KP values could reach 5.67 or more. Coronal holes rotate around the Sun every 27-28 days, this is the return of the coronal hole that produced G2 storming from September 1st through 4th. Here is the current SWPC notifications timeline posting the alert:

SWPC notifications timeline shows a G2 storm watch posted for 9/28
SWPC notifications timeline shows a G2 storm watch posted for 9/28

Geomagnetic storm watches are posted for 24 hours periods. The peak aurora conditions could happen at any time within that period. The predicted timing is based on models that esitmate the of solar wind in interplanetary space and around Earth. There is always a level of uncertainty in predicting space weather. However, with returning nature of coronal holes, the forecasts come with more confidence. In fact, based on data from SDO and STEREO-A it was possible to predict that this coronal hole had survived the rotational cycle and that there there may be a watch posted more than a week in advance of the actual storm. Here is a tweet from NLN’s Twitter feed (please consider following us!) from last week

In the image below, see the same SDO wavelength image just three days later. As the CH rotates into view, it’s shape becomes clearer and more defined. This gives the space weather models a better chance of accurately forecasting when the high speed winds will arrive at Earth

Coronal hole in geoeffective position on September 25 could induce aurora September 28
Coronal hole in geoeffective position on September 25 could induce aurora September 28

As of this writing, there are two three hour periods of G1 storming predicted on 9/28 and one period of G2 storming. Given the long duration of this storm during the last rotation, it is very possible this watch will be extended over the next several days. Here is the current NLN AuroraCast graphic for day three:

Day Three AuroraCast shows G2 storming possible on September 28
Day Three AuroraCast shows G2 storming possible on September 28

Happy Hunting

Chance For Aurora Sept 19 & 20, 2016

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Northern Lights Now – SWPC has posted a G1 geomagnetic storm watch for September 20th and 21st. The high speed wind stream from a coronal hole pointed toward Earth on Sept 17th should arrive just before midnight GMT late on Monday. For viewers in Europe and the East Coast of North America, this means there is a chance for Aurora in the hours just after sunset. Here’s an image of the coronal hole as of the 17th:

Coronal hole pointed towards Earth on 9/17 as imaged in 211 wavelength by SDO
Coronal hole pointed towards Earth on 9/17 as imaged in 211 wavelength by SDO

As of Sunday evening, the official forecast from the Space Weather Prediction Center (SWPC) shows two periods of G1 storming between 21:00 GMT on 9/19 and 03:00 GMt on 9/20. The predicted timing is visible on the NLN auroraCast:

NLN AuroraCast shows two periods of G1 storming predicted
NLN AuroraCast shows two periods of G1 storming predicted

Happy Hunting!