Yesterday’s M7.79 major solar flare produced the third large Earth-directed coronal mass ejection (CME) of the week. As a result, SWPC has posted yet another geomagnetic storm watch for Saturday and Sunday.
The flare emerged from the same active region as the previous CME producing flares this week. The sunspot region is designated beta-gamma-delta based on it’s magnetic structure. BGD is the most complex structural designation for sunspot regions and is the most likely to produce large flares and CMEs. The first CME produced an amazing show on northern lights show of Monday night with G4 (KP=8) storming when the plasma cloud arrived at Earth. The second CME was not oriented the right way to produce widespread aurora, but it did push the KP to 5 – Ian Griffin was able to capture a nice glow in New Zealand and Snoozy (@SussanSays) captured these in Tasmania:
This flare was particularly long duration. The flare just lasted just over an hour, but x-ray flux was continuing to decrease almost 3 hours later. Generally the longer duration the flare the more likely it is to produce a CME, and it produced a big one. Even though the flare happened a little west of the Earth-Sun line, there was still a halo signature and a large portion of the CME is Earth directed. The CME is traveling at around 1500 km/s, and is expected to arrive at Earth on Saturday. As a result SWPC has posted a G2 storm watch Saturday and Sunday:
We’ll be updating the exact timing of the storm’s arrival as we know more, so be sure to follow @northlightalert on Twitter for updates. It’s important to keep an eye on the data because we won’t know until the storm arrives if it is oriented correctly to disrupt the Earth’s magnetosphere and light up the sky. Space weather is an emerging field, so the prediction are still difficult to nail precisely. Aurora hunting takes a lot of patience, but when all the factors come together just right seeing aurora is an experience you will never forget.
Between now and when the storm arrives, read up on our guide with last minute tips on how to see aurora.
What an exciting time to be an Aurora hunter! After the storms from 6/22 we are now expecting a 1-2 punch, with more aurora possible Wednesday evening.
[UPDATE 4PM EST 6/24] The expected CME arrived Early, but weaker than expected and oriented the wrong way for northern lights. SWPC has downgraded the G3 watch to a G1 watch. Keep an eye on the KP, but it is unlikely this will be a big storm [END UPDATE]
Over the last 36 hours we have been treated to the second biggest aurora display of solar cycle 25, with G4 storming and KP reaching 8.67 and reading KP=8 or high for four hours. Aurora were reported as far south as North Carolina, and From from Europe to Vancouver. Aurora australis were reported on twitter from New Zealand:
The solar region that release the CME creating last night’s show released an additional CME associated with an M6.6 solar flare on Monday. This CME produced a full-halo (Earth-directed) signature on LASCO imagery. The CME was estimated to be traveling at a very fast 1047 km/s. As a result SWPC has released another G3 storm watch – the second this week, but only the 4th or 5th in the last several years:
As always with storms like this – it is still very difficult to know the impact of a storm until it arrives. The orientation of the cloud of plasma approaching Earth has to be just right to make northern lights. Yesterday’s storm was oriented with a negative Bz for almost the entire duration. It seems possible that because both CMEs came from the same active region on the sun, they might have the same orientation. Watch the 40-70 minute lead time live-KP to know your chances of seeing Aurora.
The ongoing G4 Aurora storm is living up and exceeding expectations!
Bz has been consistently and strongly South for several hours. Solar wind speeds are high at around 750km/s, and the overall Bt is around 22. For Aurora hunters, spaceweather can’t get much better than this.
Today another strong CME was launched from the Sun that should make more northern lights later this week. As a result of today’s flare, a new G1 storm watch has been issued for Tomorrow and Wednesday. It’s an exciting time to be a storm chaser.