Northern Lights Now – The expected high speed solar wind that prompted a G1 geomagnetic watch for February 17 arrived early, but delivered G1 and G2 storming conditions. The wind was faster moving than expected, clocking in around 670 km/s. The fast wind combined with periods of Bz south was enough to excite Earth’s geomagnetic fields. At the time of this blog post, there were 18 hours of continuous G1 and G2 – KP greater than 4.67 and 5.67 respectively – storming recorded, followed by another quick burst. Here is a graph showing the official readings from SWPC Boulder:
While this was a fairly strong aurora storm, there were not many aurora reports. Most of the prime viewing locations were clouded in. An large storm system across Iceland and the British Isles, general overcast across much of Scandinavia, and an East coast ice and snow storm prevented the viewers in the prime locations from experiencing this show. However, aurora hunters in some locations were able to capture the show:
New Zealand was treated to a brief period of lights just before sunrise as the storm started. Both Paul Le Comte and Ian Griffin got out of bed to snap pictures near Dunedin:
Northern Lights Now – A second G1 geomagnetic storm watch for the week is posted for Wednesday offering the possibility of KP=5 or more. The increase in aurora borealis activity is expected as the high speed solar wind arrives from the northern extension of a southern pole coronal hole. Wind speed from the coronal hole approached 600km/s as it passed the STEREO-Ahead satellite, and it appears to have extended slightly northwards since the pass. It is possible wind speeds could reach 660 km/s at Earth by Wednesday. Here’s an image of the coronal hole when it was directed towards Earth:
The current forecast from SWPC calls for a 6 hour period of potential KP=5+ starting around 3:00PM GMT. Here is NLN’s AuroraCast inforgraphic of the expected Max KP’s
As always – these watches have a +/- of about 6 hours, and about a 50% accuracy, so hope for the best and plan for the worst.
Northern Lights Now – The Space Weather Prediction Center (SWCP) has posted a G1 geomagnetic storm watch indicating probable KP>5 for February 14th and 15th 2016. This means aurora borealis may be visible in mid latitudes. The timing indicates that Europe and North America will be best positioned for a show Valentine’s Day Evening. As always with storm watches like this, the actual storming period could arrive up to 6 hours before or after the predicted arrival. Now is the time to start monitoring developments in space weather and cloudcover forecasts to know if the northern lights will be visible to you and planning your night our aurora hunting.
Update: Feb 13: NLN is now posting live updates for this storm.
As of the time the watch was posted, Earth is expected to see KP levels at 5 or above from 21:00GMT on 2/14 through 06:00GMT on 2/15 (4:00m-1:00am EST). There may be up to 12 hours past the arrival of the storm where KP may still be in the KP=4+ range. The forecast may be updated as more data comes in, so keep an eye on the NLN 3-day AuroraCast page for updates over the next couple days. As of this post, here is the current AuroraCast:
This storm is caused by a Coronal Mass Ejection (CME) that erupted from the surface of the Sun during a C8.92 flare on February 11th. You can see that eruption in the northwest (upper left) quadrant of the solar disk in this timelapse captured from the Solar Dynamic Observatory Satellite. SDO is a camera trained on the Sun that takes thousands of high resolution images per day in multiple different wavelengths. As the Flare erupts over the course of almost 90 minutes, you can see a dark area moving up and away from the eruption location. This dark area, several times the size of Earth, is the CME. It appears as dimming because the ejected plasma is cooler than the Sun and located between the Sun and the camera on the SDO sattelite.
Normally, CME’s take 2-3 days to arrive at Earth after an eruption. The eruption is moving much slower and will take 3-4 days to arrive. That could mean that it will arrive with lower solar wind speed, which would dampen chances for a great show. But it also means that as it arrives, it may put on a longer show. Stay tuned for updates!