Northern Lights Now – Several coronal holes, some flare activity and a couple CMEs may cause active aurora conditions over the next five days. Thus far, none of the CMEs appear to be Earth directed, but the sheer number of coronal holes and disturbed areas increases the likelihood that there may be an aurora show. Each of the coronal holes will produce a period of higher wind speed at Earth 2-4 days after it is directed towards Earth. Each of the disturbances that produce a CME has a chance to bring ripples in the solar wind and produce periods of negative Bz and then aurora. Here’s a look at all the current coronal holes:
Even if there is a strong aurora, it will be hard for most Northern Hemisphere viewers to get a chance to see it. Now, around the time of the summer solstice, the days are long and the nights are short. Many northern areas have zero chance of seeing a show because it will be light all day. Even further south, the nights are short, reducing the chances that the timing of an active period will line up with night time. Add to that the moon – it is full but waning over the next several days.
Our Southern hemisphere readers should have a decent shot, as they are in the depth of winter. Keep your fingers crossed for them!
UPDATE 2:00am 6/22 UTC (10PM EST 6/21)
There was indeed one brief substorm this evening that pushed the KP into G1 range! Almost immediately afterward the Bz shifted back to the north, so it is unlikely to continue:
Northern Lights Now – NLN will be live blogging tonight’s expected G2 solar storm, please come back often for updates.
Update 11:00am UTC 6/6/2016 (7:00am EST)
Sure enough! There was another substorm left in this active period. KP reached G2 levels in the 3-6am UTC period, while the short term KP forecast actually briefly reaching G3. Northern lights reports streamed in from western New York through the upper Midwest on Twitter. As of this update, KP is still in the G1 range, but the Bz shifted decisively north, so it may be done for good now. Thanks live tracking this storm with NLN! Here are some of those Twitter posts:
The storm is winding down. Solar winds are still high, but proton density and Bt have decreased. Bz is not making sustained or deep moves in the negative direction. The storm had one brief period where the short term forecast reached G2 levels, but the max three-hour activity was measured at G1. The timing of this storm also did not align well for aurora hunters as there were clouds in most places that would have been visible. New Zealand was the big winner. There still a chance a good substorm could produce Aurora for hunters in the midwest or Central Canada over the next couple hours, but it is becoming less and less likely. Here’s the graph of storm activity from this storm showing 4 periods of G1:
The storm is still stirring! The Wing-KP model is now predicting KP=5.67 in 50 minutes. Solar wind speed are over 600 km/s and Bz is moving in and out of negative. If there is a sustained negative Bz, KP could shoot up into the G3 storming range. Best bet for aurora is Europe south of the “land of the midnight Sun.” Iceland won’t be getting dark enough for a show tonight, and it’s cloudy on the American East coast. If the storm lasts long enough hunters in the western great lakes and into the plains could get lucky.
Update 2:30pm UTC 6/5/2016 (11:30am EST)
Short term predictions now include KP=5.00 or G1 storming! Expect more aurora reports from the southern hemisphere soon!
Update 2:00pm UTC 6/5/2016 (11:00am EST)
Solar wind speeds are now reading above 500 km/s, the storm is arriving. It is arriving about 12 hours later than initially forecast, but it’s here. The timing is such that most of North America missed the first part of this storm. Our Kiwi and Aussie friends should get a good show though. If the storm continues on long enough, European aurora hunters may also get a treat. There have been a couple early Aurora reports from NZ. Here’s a back of cam picture of the beginning of the storm from Ian Griffin:
Bonkersly bright display of aurora Australis going on right now get off your buns Dunedinites and enjoy the show pic.twitter.com/tDeg4X09iE
Not much to report yet. Wind speeds over the lat hour climbed to as high as 390 km/s, but are still well off of the predicted speeds. In a hint of good news, Bz has been negative over the last hour. That negative Bz has helped push the predicted Bz to 4.33, it’s highest level of the storm. This shows that even with weak wind, a strong Bt and proton density plus a favorable Bz can be enough for aurora hunters. Stay tuned, the next 12 hours could be interesting.
Update 2:30am UTC 6/5/2016 (10:30pm EST)
Over the last three hours, the solar wind environment has started to reflect the influence of the coronal hole. Density has increased from around 3-4 parts per cubic centimeter to over 10, with spikes to 40+. The solar wind speed has increased slightly from ~300 km/s to 325-350 km/s. Over the next several hours, we’re expecting solar wind to gradually increase, it could reach as high as 600 km/s. Once the wind speed is higher, watch the Bz. If it shifts south, aurora should follow soon after. Here’s a graphic of the solar wind environment from the SWPC, note the distinct change in density profile and wind speed (labeled radial speed) around 23:00:
Update 9:30pm UTC 6/4/2016 (5:30pm EST)
The first hints that the solar storm may be arriving are showing in the ACE solar wind data. Proton density has slowly increased to 5 p/cm3 over the last 45 minutes, and took a sudden jump to 11 p/cm3 in the last 5 minutes. This was accompanied by an increase in Bt to 5 nT. It will still be several hours before there is any real chance for Aurora, but this is the first hint that activity may be picking up.
Northern Lights Now – The large coronal hole that was responsible for the May 6-8 Mother’s Day G3 aurora storm is pointed toward earth again and has potential to create aurora this weekend. SWPC has posted a G2 storm watch for June 4, with a period of predicted G1 and G2 (KP=5, KP6 respectively) storming late in the UTC day. It is likely this watch will be extended to June 5 tomorrow. This means good aurora conditions are possible on Friday and Saturday evenings – particularly in the southern hemisphere where it is winter and the nights are longer.
The initial estimates for the timing of the arrival of the solar wind are often off by several hours, but the current estimates show two periods of G1 storming starting around 1500 GMT, then a period of G2 storming starting in the 2100 GMT timeperiod. This is good timing for European and North American aurora chasers, but NLN is expecting the storm to last long enough that it will be good for the evening of June 5 in New Zealand and Southern Australia. As of June 1, this is the NLN aurora clock for the day covered in the watch period: