Space Weather to Watch October 21-27

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Northern Lights Now – After somewhat quiet space weather since the last round of aurora October 9-13, there are several features to watch again. A coronal hole is pointed towards Earth and has prompted a G1 Geomagnetic Storm watch for October 24. There is a filament to the west of the coronal hole that looks like it could lift off soon and there is an active region rotating on to the east limb that was responsible for a large backsided CME just a couple days ago. Let’s take them one by one

Annotated AIA 211 image from SDO shows coronal hole, filament and new active region.
Annotated AIA 211 image from SDO shows coronal hole, filament and new active region.

Coronal Hole

The large dark area in the center of the imange is a large coronal hole pointed towards Earth right now. It has increased in size since the last rotation and is likely to bring high speed solar wind starting in three days. When it arrives there is a good chance KP values will cross into the G1 storming range. SWPC has posted a geomagnetic storm watch for Tuesday October 24.

SWPC notifications timeline shows G1 storming expected Oct. 24
SWPC notifications timeline shows G1 storming expected Oct. 24

Filament

Just to the north and west of the coronal hole there is a filament that is looking like it may lift off soon. If it does lift off, there is a chance it could produce a CME. This is worth monitoring. It is easiest to see the filament in AIA 304 as in the animated gif here:

AnimatedGIF shows the filament to the north west of the coronal hole in AIA 304
AnimatedGIF shows the filament to the north west of the coronal hole in AIA 304

New Active Region

Potentially the most promising area of interest is the active region rotating into view on the southeast limb. This is the return of AR2674 (Aug-Sept rotation) and AR 2682 (Sept-Oct rotation) after it traversed the backside of the Sun. It should be numbered AR2684 or AR2685 later this evening.

This AR was responsible for CMEs early on Oct 18 and on October 21. The CME yesterday was from an M1.1 flare that happened just over the eastern limb. This region has shown activity over the last several days that hints that it is magnetically unstable. It seems likely that it will continue to producing flaring and possibly more CMEs.

Here is the LASCO imagery showing those two CMEs

Two CMEs appear on LASCO imagery on Oct 18 and Oct 21 as a result of activity from the active region on the eastern limb
Two CMEs appear on LASCO imagery on Oct 18 and Oct 21 as a result of activity from the active region on the eastern limb

Happy Hunting!

2 thoughts on “Space Weather to Watch October 21-27”

  1. Great news! We travel from Chile to Bødo Norway to see the lights, its been awesome already can’t wait till 24th; greetings!

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