Northern Lights Now – SWPC has issued a G1 geomagnetic storm watch for potential aurora activity on Monday August 29 and Tuesday August 30, 2016. KP values could exceed 5.0. NLN will be live blogging this storm here. Check back often!
Update 8/30 13:10 UTC (09:30 am EST on 8/30)
It takes a lot of patience to hunt aurora. She was a no-show for most hunters last night. There was never quite the right environment with the Bz shifting or not strong enough and low density and the wind didn’t pick up.
Don’t write this one off yet. The bulk of the high speed wind hasn’t arrived, but it will. Over the last several hours the Bz has been much more consistently south. We could still get a show in the next 6-9 hours.
Update 8/30 06:10 UTC (02:10 am EST on 8/30)
Over the last hour, data has improved for aurora hunters. Bz has been consistently south and wind speed has ticked up above 400 km/s again. There have been a couple reports of aurora North of Toronto. With the current uptick, we expect more reports to start coming in from a little further south. Here’s the current wind data summary:
Update 8/30 05:00 UTC (01:00 am EST on 8/30)
The night is too short for our European hunters – the Sun is now coming up and they won’t see lady aurora tonight. For the East coast followers there are still about 4 hours left – but the data isn’t cooperating. Bz has taken occasional shifts into the negative rotation but none have been sustained long enough to make the lights dance in the mid latitude. For our left coast and down-under fans, there is still plenty of time. The solar wind won’t be as strong as originally predicted, but it will still come. Keep your fingers crossed that when it does arrive it brings a nice deeply southward oriented field.
Update 8/31 03:30 UTC (11:30pm EST on 8/29)
Wind speed data is starting to reflect the expected high speed stream. Readings are just under 400 km/s. Even better news: the Bz component has rotated back to a southward orientation. In the last 15 minutes it has shifted moderately strongly south with readings as low as -7.3. This should be enough that early aurora reports start flowing in from the northernmost outposts in the next 45 minutes to an hour. Please tag @northlightalert on aurora images you capture!
A note on the wing-KP: wing-KP is the model that runs NLN’s current KP real-time charts. The model is a neural net and the primary input is the 3-hour measured KP calculated for the USAF at Boulder. Because that has a three hour delay, wingKP models often underestimate the actual KP at the beginning of a storm and overestimate the values at the end of a storm. If this storm continues, it’s possible that areas that typically need a KP of 5 to see a show will get one even when the wingKP models are only registering a 4.
Update 8/31 01:20 UTC (9:20pm EST on 8/29)
A minor interplanetary shock was detected in DSCOVR data at 0100UTC. The Bz made a sudden shift from -7nT to +7nT, at the same time, density decrease and wind speeds increased slightly. This is a minor shock, but is an indicator of the leading edge of the high speed wind stream from the coronal hole is arriving. With the Bz rotating to a positive orientation, there won’t be aurora for a while. Fingers crossed that the next shock rotates the field back to negative. It is normal for the fields to oscillate a several times during the onset of an active period before settling into one predominatite orientation
Update 8/31 00:00 UTC (8:00pm EST on 8/29)
Ba has turned south and somewhat strongly. In the below snapshot from the NLN DSCOVR solar wind data page, you can see that Bz has been negative for over and hour and has been below -5nT for over 5 minutes. This, combined with the density and strong Bt should be enough to push KP into the 3s. Still waiting on the stronger solar wind. Once it arrives, it’s likely the density will drop.
Update 8/29 21:00 UTC (5:00pm EST on 8/29)
The expected solar wind speed is now late. As of 2100UTC the solar wind speeds have increased slightly to 360 km/s. That is still very slow compared to the expected wind speeds in the next several hours that could be in the 550-600 km/s range. Bz shifted north again about two hours ago. Bt and Density have remained favorable. The initial shock of the faster wind could arrive any time in the next couple hours. We’re in #WaitAndSee mode.
— Northern Lights Now (@NorthLightAlert) August 29, 2016
Update 8/29 16:00 UTC (12:00pm EST on 8/29)
Still waiting for the high speed wind to arrive. Bz made a sudden shift to negative about 4 hours ago around. If that holds, it could be a good sign for aurora hunters
Update 8/29 11:45 UTC (7:45am EST on 8/29)
Now about 6 hours away from when the forecast is calling for the first period of G1 storming. These forecasts generally have an error of +/- 6 hours. If the storming starts right on time it should be picking up just as it starts to get dark in Europe.
As you are watching the data remember that there is a delay between DSCOVR and Earth. It takes about 40-60 minutes between when a solar shock hits the satellite and when it induces aurora on Earth. That is why the real-time KP charts typically show a 60 minute lead time, they are based on the data recorded at the satellite. When the wind speed is stronger, that lead time decreases because it takes less time for the magnetic material to travel that last distance.
Update 8/29 04:00 UTC (12:00am EST on 8/29)
As expected, no sign of increased solar wind speeds yet. If you are interested in monitoring them yourself, you can find live updating charts of data from the DSCOVR satellite on NLN’s DSCOVR solar wind data page.
The weather for aurora looks great for tomorrow evening for the east coast. On this map blue means clear skies. This is for 8PM est, just before the sun sets and in the currently predicted peak of this storm:
Update 8/29 00:30 UTC (8:30pm EST on 8/28)
The G1 watch period has officially started. This storm’s activity isn’t expected to start for several more hours. Solar wind speed as measured at DSCOVR is about 375 km/s. As the storm picks up, this should increase to between 550 and 600 km/s. As it does, watch the Bz component, aurora activity will increase the as it goes negative, and will become stronger the deeper negative it is and the longer it stays there.