Remembering the great geomagnetic storming around solstice 5 years ago with a look back at pictures, data, and the #solarstorm forecast from @TamithaSkov

After periods of unsettled to active #geomagnetic conditions related to coronal holes and glancing blows of CMEs, we got hit by a small IP shock driven by a CME just before 5utc 2015-06-22

The rise in speed and density of the solar wind, and mostly south Bz component of the interplanetary magnetic field reaching around -10; brought photographable #aurora down to 38N latitude within a few hours. Kp index only reached 4.

About 12 hours after that 1st IP shock, we got hit by a much bigger one, signaling a faster stronger CME!

GOES magnetometer showed a huge deviation

Ground magnetometers reacted globally. Aurora Electrojet indices jumped off the charts!

Kp index jumped from Kp5/G1 to Kp8/G4 on the SWPC scale

We entered the core section of the CME shortly after 00utc 6/23. AE index from the 23rd

Here is a short timelapse of what the #aurora looked like on camera starting around 11:10pm mst 6/22 (5:10utc 6/23) from Paradox Valley Colorado 38N latitude

Here is the IMF and solar wind data from ACE showing a sustained strong Bt/-Bz and fast solar wind speed that led to Kp8/G4 and visible lower midlatitude #aurora as far south as Texas.

It was the peak of the geomagnetic storm. dst reached -204nT, making it the 2nd strongest storm of SC24, just behind 2015-03-17