Strong (G3) #GeomagneticStorm WATCH Valid for 09 Dec 2025

published: Sunday, December 07, 2025 04:42 UTC

A full-halo coronal mass ejection (#CME), associated with an M8.1 flare from Region 4299 at 20:39 UTC on 06 December, is expected to impact Earth early to midday on 09 December, potentially causing periods of G3 (Strong) geomagnetic storming.

Strong Geomagnetic Storm WATCH Valid for 09 December G3

WHAT: A CME is expected to arrive at Earth on 09 December and lead to increased geomagnetic field activity.

EVENT:

A coronal mass ejection (CME) is an eruption of solar material and magnetic fields. When they arrive at Earth, a geomagnetic storm can result. Watches at this level are infrequent, but not uncommon.

EXPECTATION:

A CME is anticipated to arrive at Earth early to midday on 09 December causing elevated geomagnetic field activity, and dependent upon the orientation of the embedded magnetic field, potential exists for G3-Strong storm levels.

EFFECTS:

Limited, minor effects to some technological infrastructure possible, but usually mitigatable. The aurora may become visible over many of the northern states and some of the lower Midwest to Oregon. The general public should consider monitoring our webpage for the latest information and updates.

https://www.swpc.noaa.gov/news/strong-g3-geomagnetic-storm-watch-valid-09-dec-2025

#CMEs #SpaceWeather #SolarFlares #G3

HT @g7izu

"Transpower has issued a grid emergency notice ahead of a severe geomagnetic storm and removed some South Island electricity transmission lines from service.

The national grid operator says the move won't affect the electricity supply to homes and businesses, but will prevent damage to critical equipment if the storm worsens.

Geomagnetic storms can send unwanted currents through electricity circuits, and have the potential to cause serious damage if they reach substations transformers or large hydroelectric dams.

The storms are caused by space weather, when the Sun ejects plasma and other matter in Earth's direction.

Coronal mass ejections (CME) are rare, and generally aren't noticed on earth thanks to the planet's magnetic field shielding the planet from particles, Transpower said."

https://www.rnz.co.nz/news/national/578677/grid-emergency-notice-sparked-by-solar-storm

#SolarStorm #SpaceWeather #GridEmergency #CMEs

NASA’S Parker Probe is on a mission to “touch the sun.” It’s orbiting, with each trip around a bit closer than the previous.

Parker has a camera system called WISPR that films the sun’s corona. It just recently sent back stunning images of the closest images of its atmosphere.

This is a small clip. Read more and watch the whole video here:

https://science.nasa.gov/science-research/heliophysics/nasas-parker-solar-probe-snaps-closest-ever-images-to-sun/

(Hat tip: Colossal)

#Space #Astronomy #Astrophotography #Sun #MilkyWay #NASA #ParkerProbe #CMEs

Aurora Australis from Royal National Park! This is AMAZING.

The big solar storm that is passing us this week, triggered nu a coronal mass ejection from the Sun has produced a class G4 / G5 geomagnetic storm.

Our magnetosphere deflects most of the particles from Sun away, but near the poles, some spiral down and excite our atmosphere - producing aurora.

This storm was powerful enough to generate aurora sightings as far north as Coonabarabran and the Siding Spring Observatory. That's around 340 km NW of Sydney (closer to the equator, at 31 degrees south!)

While city lights drowned out the view for many, those under darker skies were treated to an extraordinary show. This stunning timelapse footage, captured by my friend Filippo Rivetti from Royal National Park south of Sydney, offers a glimpse of the awe-inspiring beauty and planetary-scale force of this event.

A reminder of the vast, dynamic forces at play: a star lashing out across space, and a planet, our home planet with its protective magnetic shield - hosting the only life we know of so far in the Universe, safely within.

https://www.youtube.com/watch?v=cXP49hxf9ck

#AuroraAustralis #SolarStorm #SpaceWeather #Astrophysics #CMEs #Magnetosphere #Astrodon

New BMJ Tobacco Control paper out this week uses #tobaccoindustry documents!

Historical and political context for Philip Morris International’s continuing medical education courses on harm reduction -
https://doi.org/10.1136/tc-2024-059015

#CMEs #PMI #archives