Category Archives: Storm Live Blog

Sept 6/7 Aurora G3 Storm 2017 – NLN Live Blog

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Northern Lights Now – A G3 storm watch is in effect for September 6 and 7 thanks to a solar storm launched from an Earth-directed solar eruption at active region 2673. Aurora hunters are expecting a mid-latitude display. Northern Lights Now will keep you up to date on the latest information in this live blog. We’ll be updating regularly, so come back often.

NLN Live Blog Update – Wed, Sept 9, 04:45 UTC (00:45 EST 9/9)
Live blog time: 72h 45m

Whew! What a storm. There were two distinct periods of G4 storming in the last 36 hours. The first was timed well for North American aurora hunters and the second for our Europeans followers. This was a treat, especially for this late in the solar cycle.

Two periods of G4 storming in the last 36 hours. The storm is now settling down.
Two periods of G4 storming in the last 36 hours. The storm is now settling down.

The core of both CMEs has now passed and the magnetosphere should start to settle down. There still may be a couple more G1/G2 substorms in the next 24 hours, but the event is coming to an end. Thank you all for reading along and sharing your photos. Please follow NLN on Twitter and on Facebook and sign up for our email list to learn about the next storm when it comes.

NLN Live Blog Update – Wed, Sept 8, 22:00 UTC (16:00 EST 9/8)
Live blog time: 68h 00m

Bz continues to be south and wingKP is indicating G4 storming is going on again now. IF you have clear dark skies go out aurora hunting!

NLN Live Blog Update – Wed, Sept 8, 15:15 UTC (11:15 EST 9/8)
Live blog time: 63h 15m

In the last update we mentioned that it looks like another CME core is coming through. It is here now and G4 storming is happening again. Tell your friends to go out and look at the sky if it’s dark and clear! Please share this info and help your friends get a chance to see the aurora for themselves.

Second round of G4 aurora is expected to start in about 30 minutes.
Second round of G4 aurora is expected to start in about 30 minutes.

NLN Live Blog Update – Wed, Sept 8, 12:15 UTC (08:15 EST 9/8)
Live blog time: 60h 15m

What a night! There were two periods of G4 storming before the Bz shifted as Earth exited the core of CME. Aurora hunters from Europe to Central North America got a show.

From the Finnish Lapland:

From Edinburgh Scotland

Michigan:

And holy cow look at the color in this panoramic from Scott Rock in Ontario

But wait there’s more! In the last update we mentioned the possibility that there may be another CME core arriving soon. About 45 minutes ago it did as shown in the solar wind data. With Bz this strong south, we are now expecting another round of at least G3 storming over the next 1-4 hours.

Bz shows we should expect another round of aurora coming midday Sept 8 UTC
Bz shows we should expect another round of aurora coming midday Sept 8 UTC

NLN Live Blog Update – Wed, Sept 8, 05:30 UTC (01:30 EST 9/8)
Live blog time: 53h 30m

There are interesting questions about the future geomagnetic activity of this storm. The IP shocks from both the M5.5 and the X9.33 flares have now arrived. In a regular solar storm, the shock arrives and is followed soon after by the core or body of the CME. In this case, the cores of both CMEs have interacted. This is a very complex, and low confidence, forecast. The bottom line is: We might see another round of G3 storming as the body of the X9.33 CME arrives, or the body of the CME may miss Earth and it might be over. Best thing to do is watch the Bz which, by the way, just flopped back to negative. If Bz stays negative, our west coast US followers and Australia/New Zealand followers may get a show tonight.

For more detail, read this thread:

NLN Live Blog Update – Wed, Sept 8, 02:45 UTC (22:45 EST 9/7)
Live blog time: 50h 45m

Epic Aurora going on! G4 storming is logged and continues. Bz shifted back to the south, so it may slow for a bit now. Check out this small sampling of images coming in:

NLN Live Blog Update – Wed, Sept 7, 21:00 UTC (17:00 EST 9/7)
Live blog time: 45h 00m

BOOM! X9 flare CME interplanetary shock has arrived and it is bringing with it a deep negative Bz of -23nT. This is what we’ve been waiting for. Hope it is clear and dark where you are.

Solar Wind Bars show Strong Wind, Bt and neg Bz last 15 minutes.
Solar Wind Bars show Strong Wind, Bt and neg Bz last 15 minutes.
Interplanetary shock prompts major shifts in all wind parameters.
Interplanetary shock prompts major shifts in all wind parameters.

NLN Live Blog Update – Wed, Sept 7, 21:00 UTC (17:00 EST 9/7)
Live blog time: 45h 00m

Such a roller coaster. Bz shifted back south and ground based magnetometers are responding. Aurora could be dancing now.

NLN Live Blog Update – Wed, Sept 7, 20:00 UTC (16:00 EST 9/7)
Live blog time: 44h 00m

Bz switched back north. Any storming that started will end. Back to wait and see mode for the X9.33 flare CME arrival. This is why it is so rewarding when you do actually get to see an Aurora display.

NLN Live Blog Update – Wed, Sept 7, 18:15 UTC (14:15 EST 9/7)
Live blog time: 42h 15m

Bz has stayed negative since the last update. Aurora reports should start coming in from across Northern Europe as sunset arrives. WingKP is currently underestimating – KP is likely already at G1 levels. It isn’t unusual for KP to under-estimate at the beginning of storms due to the fact it is a neural net and the input is only added once every three house. Ovation is a better guide at the moment.

Ovation shows there is likely G1 storming going on now.
Ovation shows there is likely G1 storming going on now.

Full disclosure – the data doesn’t 100% line up. We’d expect ground based magnetometers to be jumping around at this point. There is an outside possibility there is bad data coming from L1 leading us astray. Proof will be in the pudding when aurora images come in.

NLN Live Blog Update – Wed, Sept 7, 15:30 UTC (11:30 EST 9/7)
Live blog time: 39h 30m

Bz just shifted sharply to the south. Time to watch the KP – should reach G1 shortly. It’s likely that Austrailia, NZ will see aurora before WingKP model reacts to this shift.

KP shifts decisively to the south.
KP shifts decisively to the south.

There was also another X class flare just now reaching X1.39

NLN Live Blog Update – Wed, Sept 7, 12:00 UTC (08:00 EST 9/7)
Live blog time: 36h 00m

36 hours into the storm watch period and KP=4 is the highest level of activity recorded so far. This is a good time to remind fellow aurora hunters that there is not yet a way to forecast the orientation of the magnetic fields in a solarstorm until it arrives. Forecasters can estimate the time of arrival and the magnitude of the storm at arrival, but if the orientation is not conducive to aurora, there won’t be a show. The first Phase of this storm was like that, it arrived within 9 hours of prediction and as strong solar wind and disturbed Bt, but Bz did not show any sustained negative orientation.

SWPC Boulder reported geomagnetic activity maxes at KP=4 so far.
SWPC Boulder reported geomagnetic activity maxes at KP=4 so far.

In the next 8-12 hours, watch for a surprise Bz negative period and for EPAM to start rising again in advance of the arrival of the CME from the X9.33 flare.

quick mea culpa: in the last update I posted the EPAM, it was late and the end of an active day of forecasting. It did not actually show EPAM still rising, I didn’t notice that the data had cut off from the chart about 4 hours from before the post until this morning. Sorry about that, and thanks to the eagle eyed readers who pointed it out!

NLN Live Blog Update – Wed, Sept 7, 04:30 UTC (00:30 EST 9/7)
Live blog time: 28h 20m

It’s NLN’s last live blog update for tonight, check back tomorrow. Leaving you with this image from EPAM. The fact that EPAM data are still up and to the right indicates that there is another CME arrival on it’s way. This aligns with the initial post 7:15am ET post yesterday morning – “Third, there may be a second shock and a new phase of Bz as a second, slower, CME arrives.”

EPAM is up and to the right indicating another incoming CME
EPAM is up and to the right indicating another incoming CME

NLN Live Blog Update – Wed, Sept 7, 04:30 UTC (00:30 EST 9/7)
Live blog time: 28h 20m

Quick update, possibly the last this evening. Bz has been mostly north over the last two hours, but it has dipped south again for the last 20 minutes. This may indicate we’re entering the next phase of the storm. If this keeps up, KP could start to climb. Hard to predict, just have to keep an eye on the data:

Ba has dipped south again over the last 20 minutes.
Ba has dipped south again over the last 20 minutes.

If you get nice photos that you are willing to share please post them to Twitter and tag the NLN account and/or post to Facebook and tag our FB page. Also – if you aren’t already, please follow and like those accounts!

NLN Live Blog Update – Wed, Sept 7, 02:00 UTC (22:00 EST 9/6)
Live blog time: 26h 00m

First round of negative Bz is happening. Wing KP responds by predicting KP=5 in 54 minutes. If Bz stays south another 10 or 15 mins, it will be go time for people in G1 range.

Bz now showing negative reading. KP should jump soon.
Bz now showing negative reading. KP should jump soon.

The first reports we’ve seen of Aurora came in from iceland with photos by long time follower and aurora hunter Muhammed Kizilkaya as the IP shock arrived at Earth about 2 and a half hours ago

NLN Live Blog Update – Wed, Sept 7, 00:45 UTC (20:45 EST 9/6)
Live blog time: 24h 45m

The CME arrived about 90 minutes ago. There may have been a first round of aurora with the initial shock, but the Bz has been positive since the arrival. In order for there to be a big show of northern lights the Bz will have to shift to negative. All solar wind metrics are strong at the moment Bt=15.35 nT, Density=15.1 p/cm3, Solar wind around 600km/s.

CME arrives at DSCOVR with a Interplanetary Shock.
CME arrives at DSCOVR with a Interplanetary Shock.

NLN Live Blog Update – Wed, Sept 6, 22:30 UTC (18:30 EST 9/6)
Live blog time: 22h 30m

With the addition of today’s X9.33 flare, the G3 Storm watch has been extended to 96 hours and continues through Sept 9. This should mean pretty almost all viewing areas should have at least some clear skies during the storm period. Also, by Sept 9 the moon is less bright and there’s a longer time between Sunset and Moonrise.

Notification timeline now shows a G3 geomagnetic storm watch extending 4 days.
Notification timeline now shows a G3 geomagnetic storm watch extending 4 days.

There are hints the shock is about to hit – temp decreasing, wind and density more variable. CME could arrive in next 30-180mins.

NLN Live Blog Update – Wed, Sept 6, 19:15 UTC (15:30 EST 9/6)
Live blog time: 19h 30m

Busy day! The active region responsible for the predicted storm produced two X class flares (so far!) today. The bigger flare was measured at X9.33 making it the biggest solar flare of the current solar cycle. The last time there was an X-Class flare was May 5, 2015. Stay tuned for more info on the CME released during this eruption. So far, initial imagery indicates it is likely to the south and west of Earth, but it’s too early to rule out a glancing blow around Sept 8/9.

As it is now getting dark in Europe, the anticipated solar storm has not arrived yet. It is a little late, but it is still well within the bounds of the prediction confidence intervals. Hang tight.

NLN Live Blog Update – Wed, Sept 6, 11:15 UTC (07:15 EST 9/6)
Live blog time: 11h 15m

As of this update, the CME has not arrived at Earth yet. Bz has been south for over an hour, which may prime the magnetosphere to ring when the shock arrives. We expect there will be at least three distinct phases to this solar storm.

Bz is south in advance of the CME shock arrival
Bz is south in advance of the CME shock arrival

First, when the initial shock hits, it will have high density (all the protons that it has swept up as it travels through space), and a big spike in wind speed. This will be measured at DSCOVR about 30-45 minutes before it arrives at Earth. Once it arrives, the aurora may dance, but the wing KP won’t reflect it yet.

Second, we will enter the first phase of the storm. It is impossible to know until it arrives if it will be oriented correctly for aurora. If Bz is negative, we should see a good show. Third, there may be a second shock and a new phase of Bz as a second, slower, CME arrives.

You can watch the Wind Speed in real time on our site (it auto-refreshes). This will be the best tool for predicting when the initial shock arrives at Earth. After that monitor the KP here.

NLN Live Blog Update – Wed, Sept 6, 03:15 UTC (23:15 EST 9/5)
Live blog time: 03h 15m

Know your local viewing conditions. The best viewing conditions are when it is dark and clear. This storm will be tricky because the forecast calls for clouds or smoke in a lot of the typical hot-spots for viewing. It is also a nearly full moon. There will be a window between sunset and moonrise that it should be really dark. You should be able to get good photos even when the moon is out – do long exposures and photograph a part of the sky where the moon isn’t.

NLN Live Blog Update – Wed, Sept 6, 00:00 UTC (20:00 EST 9/5)
Live blog time: 00h 00m

The G3 watch period has started. We aren’t expecting storming conditions to start for at least another 12 hours. In advance of the storm, watch the EPAM rise. We’ll know the initial shock of the storm hits when solar wind jumps and Bt, Bz and density make big shifts. In the meantime, here is the SWPC forecast for max KP expected in each three hour block over the next 24 hours. Expecting 7 blocks of G1 and above, 5 of G2 and above and 2 of G3.

Purple on the NLN auroraCast clock indicates expected G3 storming
Purple on the NLN auroraCast clock indicates expected G3 storming

Mid July Aurora Storm 2017 – NLN Live Blog

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Northern Lights Now – NLN will be live blogging the predicted solar storm this weekend. As of Saturday afternoon at the start of the live blog, SWPC is predicting G2 storming to start midday on July 16 UTC and last at least through July 17. NLN will be posting about this storm as it unfolds.

Thanks for hunting with NLN

BONUS – NLN Live Blog Update – Tuesday July 18, 03:20 UTC (23:20 EST 7/17)
Live blog time: BONUS ROUND

The bonus substorm is over. Time for weary aurora hunters to get some sleep.

BONUS – NLN Live Blog Update – Tuesday July 18, 02:20 UTC (22:20 EST 7/17)
Live blog time: BONUS ROUND

Space weather is still hard to predict. Solar wind data is indicating that there may be another substorm on it’s way in. Watch the Bz on the Solar Wind Page. If it stays negative, it may be worth going out in about 40min to and hour.

Bz and Wind Speed indicate the potential for a bonus sub-storm
Bz and Wind Speed indicate the potential for a bonus sub-storm

NLN Live Blog Update – Monday July 17, 17:15 UTC (12:30 EST 7/17)
Live blog time: 43h 00m

What a terrific storm. Lots of people got to see aurora in person but the big winners seemed to be in the Pacific Northwest, central and western Canada and New Zealand. The timing of the storm wasn’t great for Europe and the Northeast (except for the few diehards who persevered despite the Moon at 3am!). Overall, the storm was pretty close to the predictions – it arrived a little early but well within the standard margin of error. The predicted intensity was also close, although a little aggresive, with predictions calling for 4 periods of G2 (there were 2) and 4 periods of G1 (there were 3).

Bz has shifted North and wind speeds and density have already started declining. There’s a slight chance for another substorm as the magnetosphere is still sensitive, but this storm is basically over. Thanks for all your reports! Stay tuned for a full recap later this week.

Here are the recorded KP values from this storm (as always subject to revision, but probably won’t change):

Recap of Mid-July recorded KP values as reported by SWPC in Boulder CO
Recap of Mid-July recorded KP values as reported by SWPC in Boulder CO

NLN Live Blog Update – Monday July 17, 13:15 UTC (08:15 EST 7/17)
Live blog time: 38h 45m

Since the last update, there was one more good aurora substorm. Aurora hunters from Detroit and further west were rewarded with some really nice views early this morning. There were northern lights reports coming in from Montana, British Columbia, Mt Adam’s in Washington, and Alberta early this morning. Watch this timelapse from Detroit!

And this Beauty from Alberta

The NLN site seems to be holding up now. We made some emergency changes last nigth – and will be looking into what we can do to sure it up for the next storm. Thank you for sticking with us!

NLN Live Blog Update – Monday July 17, 05:15 UTC (00:15 EST 7/17)
Live blog time: 30h 45m

The aurora seems to be subsiding. Bz levels have been between -5 and -1 nT for the last several hours. While still negative this limits the Aurora potential to around G1 storming. There should still be plenty of opportunity to see aurora for hunters in Canada and across the northern states.

Sites down: The wing KP predictions from SWPC are still unavailable and there is no clear timeline for them being back up. SWPC is continuing to produce three-hour reports of recorded KP. Over the last three hours KP has been recorded at KP=5.00 (G1 storming). In adddition to the WingKP data being unavailable. NLN has had intermittent availability over the last several hours. High traffic has made it difficult for our servers to handle all incoming requests. Please be patient and try again soon if you are having difficulty reaching our site. Today has been our single busiest day in history – thank you for sticking with us!

NLN Live Blog Update – Sunday July 16, 20:00 UTC (16:00 EST)
Live blog time: 22h 30m

As darkness arrives in Europe the aurora is still going strong. Bz has been south, but there were a couple brief moments where it switched to a northward orientation. The variability decreases the intensity of the northern lights display. This down grades the expectations for the next 2-4 hours from G2/G3 to G1 storming with KP in the 5-6 range. That should be good enough for aurora in northern Europe once it is dark.

The SWPC wing-KP model is currently down. This is where NLN and most other aurora sites and apps get their short term KP predictions. We’re hoping SWPC gets it up and running again soon. In the meantime, you can use the ovation model found on the Short Term Prediction down? Use This! Page

Ovation model shows some decrease in aurora activity from earlier today
Ovation model shows some decrease in aurora activity from earlier today

NLN Live Blog Update – Sunday July 16, 13:15 UTC (11:15 EST)
Live blog time: 19h 30m

NLN is trying something new: join our Facebook aurora hunting event. Share with us there what you’d like to see/hear. What questions would you like NLN to answer?

NLN Live Blog Update – Sunday July 16, 13:15 UTC (09:15 EST)
Live blog time: 17h 45m

Speaking of the southern hemisphere getting a show – here’s an image of Ian Griffin in an auroraselfie this morning in New Zealand

NLN Live Blog Update – Sunday July 16, 13:00 UTC (09:00 EST)
Live blog time: 17h 30m

The storm continues to get stronger. In 50 minutes or so, the KP is expected to reach G3 levels! This is because the Bz component of the magnetic field continues to be strongly negative (-10nT or more). This is similar to the readings during the active period on May 27. For now, the timing is best for western North America and Australia/New Zealand. There is no indication yet that the activity should slow in the next 3-4 hours. European aurora hunters are left hoping the storm continues for another 8-12 hours. On the east coast, hunters should hope for another 12-16 hours of activity. Here is the current predicted KP – you can monitor the KP live on the Northern Lights Now site:

KP=6.67 predicted in just under an hour shown on the NLN live KP chart
KP=6.67 predicted in just under an hour shown on the NLN live KP chart

NLN Live Blog Update – Sunday July 16, 10:30 UTC (06:30 EST)
Live blog time: 15h 0m

The orientation of the solar storm is just right! As anticipated, the arriving solar storm is strong, but space scientists don’t have data available yet to know if the structure of the plasma cloud is right to produce aurora until it arrives. This storm is structured correctly and as a result KP is climbing and Aurora hunters are reporting success. Here is the first tweet with a northern lights picture we’ve seen tonight:

NLN Live Blog Update – Sunday July 16, 05:45 UTC (01:45 EST)
Live blog time: 8h 15m

The first indications of the arriving CME are now on display on the DSCOVR solar wind data page. The sudden increase in solar wind speed and shift in density and Bt indicate that the shock at the front of the CME has arrived at the DSCOVR satellite. The next several hours of data will be crucial in knowing if there will be a good aurora storm. Watch the Bz – if it shifts south (negative on the charts) and stays that way it means the solar storm is oriented properly to give us a show.

DSCOVR solar wind data indicates the arrival of the anticipated CME
DSCOVR solar wind data indicates the arrival of the anticipated CME

NLN Live Blog Update – Sunday July 16, 05:30 UTC (01:30 EST)
Live blog time: 8h 0m

One of the best indicators of an approaching CME is rising levels as measured by the EPAM (Electron, Proton, and Alpha-particle Monitor) instrument on ACE. Measured levels of protons increase as the CME gets closer. They peak just as the CME hits or passes Earth. When the levels increase like they are in the graph below, it is a strong indicator that the solar storm is likely to hit soon.

Rising Proton counts on the EPAM instrument indicate a CME is approaching
Rising Proton counts on the EPAM instrument indicate a CME is approaching

NLN Live Blog Update – Sunday July 16, 02:30 UTC (22:30 EST)
Live blog time: 5h 0m

The G2 storm watch has begun! While the storming isn’t expected to arrive for another 8-12 hours, forecasts are generally 6-12 hours off in either direction. If the CME is moving faster than the models anticipate, it will arrive early, if it’s slower it may not arrive until midday tomorrow. Keep your eyes on the data as activity could start at any time now. This graph from NOAA shows the storm watch as a green bar

SWPC Notifications timeline shows the G2 storm watch has begun
SWPC Notifications timeline shows the G2 storm watch has begun

NLN Live Blog Update – Sunday July 16, 23:45 UTC (19:45 EST)
Live blog time: 2h 15m

The incoming storm has the potential to bring G2 and G3 storming – but what does that mean? The G levels correspond to how strong the geomagnetic storm is. The strength is measured in Kp, a scale that goes from 0 at no activity to 9 when there is maximum activity. The higher the KP is the strong the aurora will appear and the further south they will be visible in the Northern Hemisphere and the further north they will be visible in the southern hemisphere. G2 is a reading of 5.67 on the KP scale, G3 is a reading of 6.67 on the scale. Here’s a helpful map that shows how the KP corresponds to where the lights might be visible.

Global KP boundaries map shows what KP you need to see Aurora
Global KP boundaries map shows what KP you need to see Aurora

Southern Hemisphere KP Maps
Southern Hemisphere KP Maps

NLN Live Blog Update – Sat July 15, 21:30 UTC (17:30 EST)
live blog time: 0h 0m
Here is the initial forecast for when this aurora storm will be strongest:

NLN Aurora clock shows time when Aurora may reach G1 and G2 storming
NLN Aurora clock shows time when Aurora may reach G1 and G2 storming

As always with space weather predictions there is a lot of uncertainty. The watch indicates there is the potential for G2 storming, but if the CME is oriented the wrong way as it arrives there may be minimal aurora. At the same time, if it comes it just right, there could be G3 or G4 storming that is seen as far south at Kentucky and Arizona.

Aurora May 16 through May 20 Live Blog

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Northern Lights Now – There is an extended period of active aurora predicted for the third week of May 2016. NLN is going into live-blog mode to provide updates as the storm unfolds. Please check this page often.

Some helpful links to us to watch the storms unfold:

  • Live KP: use this to see the KP over the next 45 or so minutes to time your trip outside
  • AuroraCast: NLN’s visualization of the current SWPC 3-day forecast
  • DSCOVR Solar Wind: Raw data that feeds the live KP model – be super science and predict earlier than the models!

NLN Live Blog Update – Sat May 20, 11:30 UTC (03:30 EST)

Thanks for following along the live blog! There may be some residual activity as solar wind is still high, but the storm appears to be over. Here’s a nice timelapse from @isaac_diener of last night’s activity.

NLN Live Blog Update – Sat May 20, 03:15 UTC (23:15 EST)

As anticipated, the third part of this storm is producing the most activity. But it hasn’t been much so far with geomagnetic activity just exceeding the KP=4 level. Solar winds are looking good, so there is still a chance for G1 storming in the next 3-5 hours.

Did you notice the short term KP forecast is behind? Occasionally the source data, which comes from a neural network run by the space weather prediction center goes offline. When it does, predictions come back from the model as -1. Clearly, the level of activity is not negative!

Wing KP model output  is offline - returning an estimated KP of -1
Wing KP model output is offline – returning an estimated KP of -1

When this happens, the best bet is to use the ovation aurora model – which you can find on our page title “Short Term Prediction Down? Use This!

Ovation model at the time of this update shows some activity.
Ovation model at the time of this update shows some activity.

NLN Live Blog Update – Fri May 19, 13:30 UTC (09:30 EST)

Earth is now in the coronal hole high speed wind. Wind speeds are approaching 500km/s. Over the last 45 minutes, Bz has dipped south. If this keeps up, the KP should tick back up.

Bz is now south in part three of this week's activity
Bz is now south in part three of this week’s activity

NLN Live Blog Update – Fri May 19, 01:45 UTC (21:45 EST)

With the start of 5/19 UTC, the G2 storm watch is now in effect as part three of this complex set of storms is expected to arrive. Over the last hour proton density has been steadily increasing. This is an indication that the CIR is about to arrive. It will be followed by high speed winds from the coronal hole. It should be clear in the next 3-5 hours if there will be strong aurora from this storm, of if it is another bust like the first two parts of this week’s activity. Aurora hunters world wide remain optimistic!

Proton density readings steadily rise over the last hour
Proton density readings steadily rise over the last hour

NLN Live Blog Update – Thurs May 18, 12:30 UTC (08:30 EST)

Overnight there was a brief period of northern lights between midnight and 1 am EST while the Bz was oriented southward. Since then, KP has been between 3 and 4. This was long enough for some aurora hunters to capture the show. Here are a couple clips from the NLN Twitter feed. Thanks for sharing!

NLN Live Blog Update – Thurs May 18, 04:15 UTC (00:15 EST)

Finally! Wing Kp model is calling for KP=5.00 shortly. Bz has turned south and persisted for over 2 hours, it has been hovering around -5nT for the last 30 minutes. That is strong enough to make the models predict aurora!

First predicted G1 storm period of this active period - shown on NLN's current KP real-time chart
First predicted G1 storm period of this active period – shown on NLN’s current KP real-time chart

NLN Live Blog Update – Thurs May 18, 01:00 UTC (21:00 EST)

Another quiet day. The maximum measured KP was 2.67. It appears the expected CME went to the South of Earth and we won’t be seeing any impact from it. SWPC updated the watches. They have cancelled the G2 watch for the 17th and downgraded the watch on the 18th to a G1 watch. They did maintain the G2 watch for the 19th and extend a new G1 watch to the 20th.

The third part of the expected storm should start to impact Earth late on the 18th (UTC) as Earth crosses a solar sector boundary and a co-rotating interactive boundary in advance of the wind from the next coronal hole. Then activity should pick up on the 19th as Earth enters the high speed wind from the coronal hole. This is illustrated in the WSA-Enlil (How to read Enlil ) below. Earth is the green filled circle on each of the graphs. At the top, see that density is high as Earth is in the SSBC, on the lower portion, see that wind speeds are picking up as Earth enters the wind stream.

Annotated Frame from WSA_Enlil model shows coronal holes, high speed wind arriving and high density from SSBC
Annotated Frame from WSA_Enlil model shows coronal holes, high speed wind arriving and high density from SSBC

It’s worth checking out the fully animated WSA-Enlil output at SWPC

NLN Live Blog Update – Wed May 17, 11:00 UTC (07:00 EST)

Solar wind speeds have been slowly decreasing overnight as the influence from the first coronal hole wanes. Winds speeds have dropped to around 500km/s. Bz has been oriented southward (negative) for over 2 hours now. The combination what is responsible for pushing short-term Kp predictions to between 3 and 4. Even with the strength of the field low, extended periods of Bz like this can lead to aurora. We aren’t expecting any amazing jumps in Kp until other solar wind parameters become more favorable.

The next feature that may become evident in this storm is the arrival or glancing blow from the CME that launched late on May 13. The material from the CME is slow moving and mostly to the south of Earth. SWPC models are indicating some of the material may have been on the Earth-Sun plane. Here is a snapshot of the CME in lasco C2 and C3 imagery. It is faint, but the CME can be seen as a “cloud” emanating from the bottom right of the Sun at starting around the 21:00 timestamp in C2 (orange/red) and the 22:30 timestamp in C3 (blue)

CME launches late on 5/13 as shown in LASCO C2 imagery from SOHO
CME launches late on 5/13 as shown in LASCO C2 imagery from SOHO
The same CME, but imaged in C3 - zoomed out a little.
The same CME, but imaged in C3 – zoomed out a little.

NLN Live Blog Update – Wed May 17, 03:45 UTC (11:45 EST)

As of midnight, a G2 storm watch is now in effect. SWPC extended the watch an additional 24 hours through May 19. The 19th currently looks like it will be the most active day this week. G1 and G2 storming is predicted for all but one 3-hour period during the that day. Here is the NLN AuroraCast showing the predicted KP for each 3-hour time period over the next three days.

3-day AuroraCast shows very active geomagnetic activity the next three days - particularly on May 19
3-day AuroraCast shows very active geomagnetic activity the next three days – particularly on May 19

For the first day of this event, measured KP peaked at 3.00. Storm levels did not reach the G1 threshold.

NLN Live Blog Update – Tue May 16, 21:00 UTC (17:00 EST)

Despite a G1 storm watch posted for today, it doesn’t appear KP levels will reach 4.67 today. Solar wind speed have increased as a result of the coronal hole high speed stream and have been above 500km/s for most of the day. Solar winds reached a peak speed of 678km/s early in the UTC day, but have since declined. It is not unusual that a predicted G1 storm does not live up to expectations, there is plenty of activity predicted for the next 2 days and probably more. Stay tuned.