Coronal mass ejection arrival

Tuesday, 19 January 2016 01:31 UTC

Coronal mass ejection arrival

Yesterday around 20:55 UTC we saw a minor shock in the solar wind which is likely the arrival of the filament coronal mass ejection of 15 January.

More about that eruption can be read here.

The solar wind speed increased from 300 to 370km/s when the shock passed ACE and the IMF slowly turned into a prelonged negative (southward) orination averaging out at about -6nT. At the time of writing, the observed Wing-Kp index hasn't increased beyond -3 but the NOAA SWPC did report that the Kp4 threshold (active geomagnetic conditions) has been reached. Active geomagnetic conditions (Kp4) remains possible in the hours ahead if the direction of the IMF (Bz) continues to be southward. Sky watchers near the US-Canadian border should be alert for auroral displays in the hours ahead.

Any mentioned solar flare in this article has a scaling factor applied by the Space Weather Prediction Center (SWPC), the reported solar flares are 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.

Thank you for reading this article! Did you have any trouble with the technical terms used in this article? Our help section is the place to be where you can find in-depth articles, a FAQ and a list with common abbreviations. Still puzzled? Just post on our forum where we will help you the best we can! Never want to miss out on a space weather event or one of our news articles again? Subscribe to our mailing list, follow us on Twitter and Facebook and download the SpaceWeatherLive app for Android and iOS!

Latest news

Support SpaceWeatherLive.com!

A lot of people come to SpaceWeatherLive to follow the Solar activity or if there is a chance to see the aurora, but with more traffic comes higher costs to keep the servers online. If you like SpaceWeatherLive and want to support the project you can choose a subscription for an ad-free site or consider a donation. With your help we can keep SpaceWeatherLive online!

No Ads on SWL Pro!
No Ads on SWL Pro! Subscriptions
Donations
Support SpaceWeatherLive.com! Donate
Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2026/02/04X4.21
Last M-flare2026/03/18M2.7
Last geomagnetic storm2026/03/20Kp7- (G3)
Spotless days
Last 365 days3 days
20263 days (4%)
Last spotless day2026/02/24
Monthly mean Sunspot Number
February 202678.2 -34.3
March 202677.5 -0.7
Last 30 days63.5 -42.2

This day in history*

Solar flares
12001M2.65
22013M2.32
32000M1.51
42001M1.41
52000M1.26
DstG
11990-136G3
21998-85G2
32001-83
41974-77G3
51989-75
*since 1994

Social networks