A glancing blow CME from the July 20 eruption could bring a chance for G1 – Minor geomagnetic storm condition on July 23, 2021. As a result, a G1 Geomagnetic Storm Watch is in effect.
A ~4-degree solar filament centered at approximately N25E65 erupted from the visible disk from 16:00 to 16:30 UTC on July 20.
The disappearing solar filament (DSF) was associated with a B5-level enhancement at 16:33 UTC. Coronal mass ejection (CME) signatures were evident in available GOES-16 SUVI imagery.
STEREO-A imagery, as it became available, revealed a partial, northern favoring halo.
However, after further analysis and modeling by SWPC, initial results suggest a possible glancing blow later on July 23.
Space Weather Message Code: WATA20
Serial Number: 897
Issue Time: 2021 Jul 21 2029 UTC
WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
Jul 22: None (Below G1) Jul 23: G1 (Minor) Jul 24: None (Below G1)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents – Weak power grid fluctuations can occur.
Spacecraft – Minor impact on satellite operations possible.
Aurora – Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.
Featured image credit: NASA SDO/AIA 171
If you value what we do here, create your ad-free account and support our journalism.
Your support makes a difference
Dear valued reader,
We hope that our website has been a valuable resource for you.
The reality is that it takes a lot of time, effort, and resources to maintain and grow this website. We rely on the support of readers like you to keep providing high-quality content.
If you have found our website to be helpful, please consider making a contribution to help us continue to bring you the information you need. Your support means the world to us and helps us to keep doing what we love.
Support us by choosing your support level – Silver, Gold or Platinum. Other support options include Patreon pledges and sending us a one-off payment using PayPal.
Thank you for your consideration. Your support is greatly appreciated.