| No. | Type | Alerts | Warnings | Watches |
|---|---|---|---|---|
| 1 | Kp Index Warning |
G3:
04:30 (GMT) on Sat 4 Jul 2026 to 12:00 (GMT) on Sat 4 Jul 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 influence of the latest CME arrival is expected to ease through today, with only minor auroral enhancements possible this evening. Any auroral displays are likely to be confined to northern parts of the UK and other locations at similar geomagnetic latitudes. The next increase in activity is anticipated late on 05 July or during the early hours of 06 July (UTC) with the arrival of another CME. This may allow auroral displays to be visible from Scotland, Northern Ireland and much of northern England during the limited hours of darkness.
Southern Hemisphere
The influence of the latest CME arrival is expected to ease through today, with only minor auroral enhancements possible this evening. Any auroral displays are likely to be confined to southern parts of New Zealand and other locations at similar geomagnetic latitudes. The next increase in activity is anticipated late on 05 July or during the early hours of 06 July (UTC) with the arrival of another CME. Any aurora might become visible across much of southern New Zealand and comparable latitudes.
Issued at: 08:22 (GMT) on Sat 4 Jul 2026
Forecast overview
Space Weather Forecast Headline: Moderate solar activity expected. G1/Minor geomagnetic storms likely, chance G2/Moderate storms Days 1-2 (04-05 Jul), activity declining later in the period. Chance of S1/Minor radiation storms.
Analysis of Space Weather Activity over past 24 hours
Solar Activity: Solar activity has been High with 5 Moderate-class flares observed in the last 24 hours, the largest at 03/1811UTC, from the region in the northwest. This is just about the largest spot on the disk, and has been showing development of penumbra within the intermediate portion. There is still thought to be magnetic complexity within this region, although as it approaches the limb this is becoming more difficult to assess. A region in the southwest is just slightly smaller than the first mentioned but has been showing decay within its trailing portion. It does appear to have developed magnetic complexity to the south of the main leader, however. Another region in the southwest appears to have simplified as it approaches the limb, but again its proximity to the limb makes full assessment difficult. The new region in the east is small and simple.
Coronal Mass Ejections (CMEs) associated with the two recent flares from the regions in the west are still undergoing analysis. The bulk of any CME is expected to pass ahead of Earth's orbit, however.
Solar Wind / Geomagnetic Activity: Solar winds showed a CME arrival at 03/1119 UTC, likely followed by a further CME around 03/1900 UTC. Wind speeds were slow, around 380 km/s, increasing after the CME arrivals to become elevated between 530-600 km/s. Total Interplanetary Magnetic Field was weak at first, increasing to moderate and then strong. The north-south component varied weakly at first, but became strongly variable. Geomagnetic activity was Quiet to Active (Kp 0-4).
Energetic Particles / Solar Radiation: The count rate of energetic particles (high energy protons) was at background levels, but with a recent slight increase, although levels remain well below the S1/Minor radiation storm threshold.
Four-Day Space Weather Forecast Summary
Solar Activity: Moderate activity is expected, with occasional Moderate-class flares and a slight chance of an isolated Strong flare. This risk declining slightly during the period.
Solar Wind / Geomagnetic Activity: CME influence continues to affect Earth, with elevated solar wind speeds, this likely to decline Day 1 into Day 2 (04-05 Jul). Further CMEs emitted 01-02 Jul may give additional CME arrivals on Days 2-3 (05-06 Jul), with perhaps the main CME of interest most likely to sweep up any other CMEs and arrive at Earth around 05/1600 UTC, but with some uncertainty in arrival time. Two further flares appear to have produced CMEs but these are awaiting imagery for analysis. The bulk of any CME(s) is expected to pass ahead of Earth's orbit, however. A coronal hole in the south of the disc may give a slight additional enhancement to the solar wind environment alongside the expected CME(s).
Geomagnetic activity is expected to be Unsettled to G1/Minor storm with a chance of G2/Moderate storms to start Day 1. Activity is likely to decrease into Day 2 to become Quiet to Unsettled, before any further CME influence later Day 2 into Day 3 brings the possibility of Unsettled to G1/Minor storm with a chance of G2/Moderate storms once again. Activity is then likely to be mostly Quiet for Day 4 (07 Jul), in the absence of any further CME activity.
Energetic Particles / Solar Radiation: The count rate of energetic particles (high energy protons) is currently slightly enhanced, but well below the S1/Minor radiation storm level. There is a chance of reaching above the S1 level during this period.
Issued at: 00:14 (GMT) on Sat 4 Jul 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: