| No. | Type | Alerts | Warnings | Watches |
|---|---|---|---|---|
| 1 | Kp Alert |
G1:
06:00 (GMT) on Tue 8 Sep 2026 to 09:00 (GMT) on Tue 8 Sep 2026 |
Space Weather
Space weather describes changing environmental conditions in near-Earth space. Magnetic fields, radiation, particles and matter, which have been ejected from the Sun, can interact with the Earth’s upper atmosphere and surrounding magnetic field to produce a variety of effects.
Space weather notifications
Aurora forecasts
Northern Hemisphere
The geomagnetic forecast is complex, with the ongoing fast wind likely to be amplified later Tuesday 08 September by glancing incidence CMEs and a final more obliquely-aimed CME. Together these give a chance of high geomagnetic latitude aurora from the current evening, perhaps northern Scotland and equivalent at first, but possibly more widely across northern UK at peak later Tuesday and early Wednesday (UTC).
Southern Hemisphere
The geomagnetic forecast is complex, with an initial fast wind and perhaps a minor CME expected in the current UTC day likely to be amplified later Tuesday 08 September by glancing incidence CMEs and a final more obliquely-aimed CME. Together these give a chance of high geomagnetic latitude aurora from the current evening, perhaps far southern New Zealand and equivalent at first, but possibly more widely across Tasmania and New Zealand's South Island at peak later Tuesday and early Wednesday (UTC).
Issued at: 01:59 (GMT) on Tue 8 Sep 2026
Forecast overview
Space Weather Forecast Headline: Chance of Moderate Geomagnetic Storm G2 days 1 and 2 (8/9 Sep)
Analysis of Space Weather Activity over past 24 hours
Solar Activity: Activity has been Low, peaking with an isolated Common-class flare observed at 07/0901UTC from a sunspot region just east of the middle of the Sun.
There are currently up to seven sunspot regions. Much of the facing side comprises simple, stable magnetically unipolar groups in visible light.
CME activity in the period was from the far-side, with a large CME visible in imagery from behind the eastern solar horizon. This has a similar longitude to an oncoming active region, which, if not a one-off event, might affect the forecast later this week.
Solar Wind / Geomagnetic Activity: Solar winds showed an initial slow regime, potentially giving way to a precursor to a fast wind after 07/0500UTC. This change accelerated around 07/1200UTC, as a coronal hole fast wind arrived.
The solar wind speed rose from background to become elevated. The number of particles in the solar wind was average at first, but rose to an above average peak. The associated magnetic field saw a similar increase from weak to strong, with the north-south component varying erratically.
The net result of the above solar wind measures was for initially quiet but increasing geomagnetic activity, remaining below Minor Geomagnetic Storm G1 throughout.
Energetic Particles / Solar Radiation: Solar radiation levels showed a continuing decline to resting background following the S1/Minor SEP event on 05 September.
Four-Day Space Weather Forecast Summary
Solar Activity: There is a slight chance of mainly low activity increasing to moderate on day 1 (8 Sep) perhaps rising to a chance thereafter due to the expected return of a far-sided active region. No significant departures are due in the period.
Solar Wind / Geomagnetic Activity: The geomagnetic forecast is complex. Earth has connected with the fast wind from CH91/+, this may result in a peak Chance of G1 in the first 24 hours. Up to three CMEs are then due to connect with Earth from later day 1 (8 Sep) into Day 2 (9 Sep). These CMEs give a broad peak Chance of Moderate geomagnetic storm G2 straddling these days, with the peak risk centred on the midnight dividing them, but perhaps earlier than previous guidance given revised modelling. Confidence lowers later in the forecast period, with the tail of these CMEs' influence fading. Later on day 4 (11 Sep) a fast wind from CH92/+ may also connect with Earth, this is a non-recurrent feature and confidence is low.
Energetic Particles / Solar Radiation: Solar radiation is now near resting background. There is a slightly higher residual risk than is typical for the current cohort of sunspot regions, although the daily risk is still slight.
Issued at: 00:23 (GMT) on Tue 8 Sep 2026
Solar imagery
SDO AIA-193
This channel highlights the outer atmosphere of the Sun - called the corona - as well as hot flare plasma. Hot active regions, solar flares, and coronal mass ejections will appear bright here. The dark areas - called coronal holes - are places where very little radiation is emitted, yet are the main source of solar wind particles.
Issued at:
SDO AIA-304
This channel is especially good at showing areas where cooler dense plumes of plasma (filaments and prominences) are located above the visible surface of the Sun. Many of these features either can't be seen or appear as dark lines in the other channels. The bright areas show places where the plasma has a high density.
Issued at: