Space Weather

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.

Image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams

Space weather notifications

No. Type Alerts Warnings Watches
2 Geomagnetic Storm Watch
G4:
08:16 (UTC) on Thu 27 Jun 2024
to 08:17 (UTC) on Sat 27 Jul 2024
G5:
08:17 (UTC) on Thu 27 Jun 2024
to 08:17 (UTC) on Mon 29 Jul 2024
2 Kp Index Warning
G5:
06:00 (UTC) on Thu 27 Jun 2024
to 08:22 (UTC) on Sat 27 Jul 2024
G4:
06:00 (UTC) on Thu 27 Jun 2024
to 08:22 (UTC) on Sat 27 Jul 2024
2 Proton Flux 10MeV Alert
S2:
04:55 (UTC) on Sat 8 Jun 2024
2 Xray Radio Blackout Alert
R3:
02:33 (UTC) on Sun 14 Jul 2024
Last updated 03:35 (UTC) on Tue 16 Jul 2024

Space weather notifications explained

Different aspects of space weather have a variety of impacts on mankind and the technology we use. The Met Office Space Weather Operations Centre (MOSWOC) uses numbered scales developed by the National Oceanic and Atmospheric Administration (NOAA). These scales are similar to those used to describe hurricanes or earthquakes and are used worldwide to classify space weather conditions and communicate the impact on people and systems.

We have developed a UK-specific impact scale to use in forecasts, alerts and warnings based on the 2013 Royal Academy of Engineering report on the impacts of extreme space weather on engineered systems and infrastructures specific to the UK.

You can see the scales below for three different types of space weather:

  • Radio blackouts (R Scale)
  • Geomagnetic storms (G Scale)
  • Solar radiation storms (S Scale)

Radio blackouts

The ionosphere is a dynamic part of the upper atmosphere which acts as a reflector for long-range, high-frequency communications (HF comms). During a solar flare, the increase in radiation from the sun causes the ionosphere to absorb rather than reflect signals, disrupting communications systems on the sunlit side of the Earth. The sun may also emit radio bursts at multiple wavelengths causing various problems for communication and navigation systems.

Even during periods of quiet solar activity, turbulence in the ionosphere can result in a scattering of electromagnetic waves disrupting navigation systems like Global Navigation Satellite Systems (GNSS) or Global Positioning System (GPS) and radio bands up to the GHz frequencies. These are referred to as radio blackouts.

Category UK effect * US & global effect * Physical measure Average frequency (1 cycle - 11 years)
Scale Descriptor GOES X-ray peak brightness by class and by flux No. of events when flux level was met: (no. of storm days)
R5 Extreme HF Radio: Complete HF (high-frequency*) radio blackout on the entire sunlit side of the Earth, lasting for a number of hours. This results in no HF radio contact with mariners and en route aviators in this sector. HF Radio: Complete HF (high-frequency*) radio blackout on the entire number of hours. This results in no HF radio contact with mariners and en route aviators in this sector.

Navigation: Low-frequency navigation signals used by maritime and general aviation systems experience outages on the sunlit side of the Earth for many hours, causing a loss in positioning. Increased satellite navigation errors in positioning for several hours on the sunlit side of the Earth, which may spread into the night side.

X20

(2 x 10-3)

Less than 1 per cycle
R4 Severe HF Radio: HF radio communication blackout on most of the sunlit side of Earth for one to two hours. HF radio contact lost during this time. HF Radio: HF radio communication blackout on most of the sunlit side of Earth for one to two hours. HF radio contact lost during this time.

Navigation: Outages of low-frequency navigation signals cause an increased error in the positioning of satellite navigation possible on the sun side of Earth.

X10

(10-3)

8 per cycle

(8 days per cycle)

R3 Strong HF Radio: Wide area blackout of HF radio communications, loss of radio contact for about an hour on the sunlit side of Earth. HF Radio:Wide area blackout of HF radio communication, loss of radio contact for about an hour on the sunlit side of Earth.

Navigation: Low-frequency navigation signals degraded for about an hour.

X1

(10-4)

175 per cycle

(140 days per cycle)

R2 Moderate HF Radio: Limited blackout of HF radio communication on sunlit side, loss of radio contact for tens of minutes. HF Radio: Wide area blackout of HF radio communication, loss of radio contact for about an hour on the sunlit side of Earth.

Navigation: Low-frequency navigation signals degraded of about an hour.

M5

(5 x 10-5)

350 per cycle

(300 days per cycle)

R1 Minor HF Radio: Weak or minor degradation of HR radio communication on sunlit side, with occasional loss of radio contact. HF Radio: Weak or minor degradation of HF radio communication on the sunlit side, with occasional loss of radio contact.

Navigation: Low-frequency navigation signals degraded for brief intervals.

M1

(10-5)

2000 per cycle

(950 days per cycle)

* Duration of the event will influence the severity of effects
** Other frequencies may be affected by these conditions

Geomagnetic storms

Geomagnetic storms are large disturbances in the Earth's magnetic field caused by changes in the solar wind and interplanetary magnetic field (IMF) structure. These changes in the solar wind arise from disturbances on the sun, such as in powerful coronal mass ejections (CMEs). Their effect can be felt for a number of days. With the right magnetic configuration, and increases in solar wind speed and density, large amounts of energy can be transferred into the Earth's geomagnetic system.

The effect of geomagnetic storms can result in impacts to power systems, spacecraft operations and other communication.


Category UK effect * US & global effect * Physical measure Average frequency (1 cycle - 11 years)
Scale Descriptor Kp values ** No. of storm events when kp level was met; (no. of storm days)
G5 Extreme Power systems: Localised voltage control and protective system problems may occur, leading to the potential for localised loss of power. Transformers may experience damage.

Spacecraft operations: May experience extensive surface charging, drag may increase on low-Earth-orbit satellites, problems with orientation, uplink/downlink and tracking satellites.

Other systems: HF (high-frequency) radio communication may be impossible in many areas for one to two days. GNSS (GPS) satellite navigation may be degraded for days with possible effects on infrastructure reliant on GSS (GPS) for positioning or timing. Low-frequency radio navigation can be out for hours, and aurora may be seen across the whole of the UK.

Power systems: Widespread voltage control and protective system problems can occur. Some grid systems may experience complete collapse or blackouts. Transformers may experience damage.

Spacecraft operations: May experience extensive surface charging, drag may increase on low-Earth-orbit satellites, problems with orientation, uplink/downlink and tracking satellites.

Other systems: Pipeline currents can reach hundreds of amps. HF (high-frequency) radio propagation may be impossible in many areas for one to two days. Satellite navigation may be degraded for days. Low-frequency radio navigation can be out for hours, and aurora has been seen as low as Florida and southern Texas (typically 40-degree geomagnetic lat).***

Kp = 9 4 per cycle

(4 days per cycle)

G4 Severe Power systems: No significant impact on UK power grid likely.

Spacecraft operations: May experience surface charging and tracking problems, drag may increase on low-Earth-orbit satellites, corrections may be needed for orientation problems.

Other systems: HF radio propagation sporadic, GNSS(GPS) satellite navigation degraded for hours, low-frequency radio navigation disrupted, and aurora may be seen across the whole of the UK.

Power systems: possible widespread voltage control problems and some protective systems will mistakenly trip out key assets from the grid.

Spacecraft operations: May experience surface charging and tracking problems, corrections may be needed for orientation problems.

Other systems: Induced pipeline currents affect preventive measures, HF radio propagation sporadic, satellite navigation degraded for hours, low-frequency radio navigation disrupted, and aurora has been seen as low as Alabama and northern California (typically 45-degree geomagnetic lat.)***

Kp = 8, including a 9- 100 per cycle

(60 days per cycle)

G3 Strong Power systems: No significant impact on UK power grid likely.

Spacecraft operations: Surface charging may occur on satellite components, drag may increase on low-Earth-orbit satellites, and corrections may be needed for orientation problems.

Other systems: Intermittent GNSS(GPS) satellite navigation and low-frequency radio navigation problems may occur, HF radio may be intermittent. Aurora may be seen in Scotland and Northern Ireland and as low as Mid-Wales and the Midlands.

Power systems: Voltage corrections may be required, false alarms triggered on some protection devices.

Spacecraft operations: Surface charging may occur on satellite components, drag may increase on low-Earth-orbit satellites, and corrections may be needed for orientation problems.

Other systems: Intermittent satellite navigation and low-frequency radio navigation problems may occur, HF radio may be intermittent, and aurora has been seen as low as Illinois and Oregon (typically 50-degree geomagnetic lat).***

Kp = 7 200 per cycle

(130 days per cycle)

G2 Moderate Power systems: No impact on UK power grid.

Spacecraft operations: Corrective actions to orientation may be required by ground control; possible changes in drag affect orbit predictions.

Other systems: HF radio propagation can fade at higher latitudes, and aurora may be seen across Scotland.

Power systems: High-latitude power systems may experience voltage alarms, long-duration storms may cause transformer damage.

Spacecraft operations: Corrective actions to orientation may be required by ground control; possible changes in drag affect orbit predictions.

Other systems: HF radio propagation can fade at higher latitudes, and aurora has been seen as low as New York and Idaho (typically 55-degree geomagnetic lat).***

Kp = 6 600 per cycle

(360 days per cycle)

G1 Minor Power systems: No impact on UK power grid.

Spacecraft operations: Minor impact on satellite operations possible.

Other systems: Aurora may be seen as low as Northern Scotland.

Power systems: Weak power grid fluctuations can occur.

Spacecraft operations: Minor impact on satellite operations possible.

Other systems: Migratory animals are affected at this and higher levels; aurora is commonly visible at high latitudes (northern Michigan and Maine).***

Kp = 5 1700 per cycle

(900 days per cycle)

* Duration of the event will influence the severity of effects
** The Kp-index used to generate these messages is derived from a real-time network of observatories that report data to SWPC in near real-time. In most cases, the real-time estimate of the Kp-index will be a good approximation to the official Kp indices that are issued twice per month by the German GeoForschungsZentrum (GFZ) (Research Center for Geosciences).
*** For specific locations around the globe, use geomagnetic latitude to determine likely sightings

Solar radiation storms

In association with large solar flares, solar radiation storms may also occur. These storms, consisting of very high energy protons, primarily impact polar regions. This is called polar cap absorption, and their main effect is to degrade HF comms in these regions.

In space, astronauts and satellites can be exposed to increased levels of radiation. While extra-vehicular activity (spacewalks) can be avoided during a solar storm, satellites could be exposed to excessive and damaging radiation levels. For instance, solar panels can be degraded (reducing the life expectancy of the satellite), surface charging can damage the electronics and radiation can result in errors within computer systems.

Although the atmosphere provides a significant level of protection, charging and radiation from space weather events have been shown to impact ground-based systems occasionally. Similarly, aircraft, crews and passengers on high latitude polar routes may, on very rare occasions, be exposed to elevated radiation levels.


Category UK effect * US & global effect * Physical measure Average frequency (1 cycle - 11 years)
Scale Descriptor Flux levels of >= 10 MeV particles (ions) ** No. of storm events when kp level was met; (no. of storm days)
S5 Extreme Biological: Passengers and crew in aircraft on certain routes may be exposed to increased radiation levels. The increase depends on the flight path and the detailed storm characteristics.****

Spacecraft operations: Some satellites may suffer temporary outages due to memory impacts, which can cause loss of control, serious noise in image data or orientation problems and permanent damage to solar panels.

Aircraft operations: Some aircraft electronic systems may experience single events effects (SEE) which can cause upsets or unexpected behaviour. The rate of SEE depends on the flight path and the detailed storm characteristics. ****

Biological: Unavoidable high radiation hazard to astronauts on EVA (extra-vehicular activity); passengers and crew in high-flying aircraft and high latitudes may be exposed to radiation risk. ****

Satellite operations: Satellites may be rendered useless, memory impacts can cause loss of control, may cause serious noise in image data, star-trackers may be unable to locate sources; permanent damage to solar panels possible.

Aircraft operations: Pipeline currents can reach hundreds of amps. HF (high-frequency) radio propagation may be impossible in many areas for one to two days. Satellite navigation may be degraded for days, low-frequency radio navigation can be out for hours, and aurora has been seen as low as Florida and southern Texas (typically 40-degree geomagnetic lat).***

105 Fewer than 1 per cycle
S4 Severe Biological: Passengers and crew in aircraft on certain routes may be exposed to increased radiation levels. The increase depends on flight path and the detailed storm characteristics.****

Satellite operations: Some satellites may suffer temporary outages, due to single event effects on electronics which can cause unexpected behaviours, noise in image data or orientation problems and permanent damage to solar panels.***.

Aircraft operations: Some aircraft electronics systems may experience single event effects (SEE) which can cause upsets or unexpected behaviour. The rate of SEE depends on flight path and the detailed storm characteristics. ****

Biological: Unavoidable radiation hazard to astronauts on EVA; passengers and crew in high flying aircraft at high latitudes may be exposed to radiation risk. ****

Satellite operations: May experience memory device problems and noise on imaging systems; star-tracker problems may cause orientation problems, and solar panel efficiency can be degraded.

Aircraft operations: Blackout of HF radio communications through the polar regions and increased navigation error over several days are likely.***

104 3 per cycle
S3 Strong Biological: Passengers and crew in aircraft on certain routes may be exposed to increased radiation levels. The increase depends on flight path and the detailed storm characteristics.****

Satellite operations: A small number of satellites may experience outages due to single event effects, which can cause unexpected behaviours, noise on imaging systems and orientation problems.

Aircraft operations: Some aircraft electronic systems may experience single event effects (SEE) which can cause upsets or unexpected behaviour. The rate of SEE depends on flight path and the detailed storm characteristics. ****

Biological: Radiation hazard avoidance recommended for astronauts on EVA; passengers and crew in high-flying aircraft at high latitudes may be exposed to radiation risk. ****

Satellite operations: Single-event upsets, noise in imaging systems, and slight reduction of efficiency in solar panel are likely.

Aircraft operations: degraded HF radio propagation through the polar regions and navigation position errors likely.***

103 10 per cycle
S2 Moderate Biological: No additional risk.****

Satellite operations: Infrequent single-event upsets possible.

Aircraft operations: Unlikely to have significant effect. ****

Biological: Passengers and crew in high-flying aircraft at high latitudes may be exposed to elevated radiation risk. ****

Satellite operations: Infrequent single-event upsets possible.

Aircraft operations: Small effects on HF propagation through the polar regions and navigation at polar cap locations possibly affected.***

102 25 per cycle
S1 Minor Biological: None.****

Satellite operations: None.

Aircraft operations: Unlikely to have an effect. ****

Biological: None. ****

Satellite operations: None.

Aircraft operations: Minor impacts on HF radio in the polar region.***

10 50 per cycle
* Duration of the event will influence the severity of effects
** Flux levels are 5-minute averages. Flux in particles.s-1.ster-1.cm-2. Based on this measure, but other physical measures are also considered
*** These events can last more than one day
**** High energy particle measurements (>-400 MeV) are a better indicator of radiation risk to aircraft avionics, passengers and crews. Pregnant women are particularly susceptible.

Types of notifications

The Met Office issues a number of different types of notifications triggered by space weather activity. These notifications fall into the following categories:

  • A watch is a long lead time message for potential increases in geomagnetic activity only.
  • A warning is issued when certain conditions are expected for a period of time.
  • An alert is issued when an event threshold has been crossed.
  • A summary is issued at the end of an event, confirming the start and end time and peak measurement during the event.
  • Cancellation may be issued when either actual or forecast space weather conditions change to such an extent that the forecaster considers a watch or a warning is no longer valid.

Aurora forecasts

Northern Hemisphere

UAT testing 1st May 2024 - Simplified

Southern Hemisphere

UAT TEST 7th FEB

Issued at:

Forecast overview

Space Weather Forecast Headline: Moderate-class X-ray flares likely (R1-R2 radio blackouts).

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Solar activity has been Moderate, with a triple-peak moderate flare at 15/0937 UTC originating from the large region in the southwest, this sunspot accompanies 15 other spots on the disk, but is by far the largest and most complex region. The next largest region is in the southeast, this spot continues to develop in size and complexity. There are two small and unstable spots near centre disk which also pose a threat of flaring. All other regions are considered to be relatively small and simple at present.

Despite the number and scale of solar flares, no Earth-directed coronal mass ejections have been observed.

Solar Wind / Geomagnetic Activity: The solar wind signal comprised variations on a slow regime, with a late enhancement noted. The solar wind speed was at background levels but rose a little to end the period. The interplanetary magnetic field was weak, becoming moderate from 15/2150UTC. The north-south variation was also weak initially, becoming consistently negative and moderate after 15/2200 UTC. The net result of the above solar wind measures was Quiet (Kp 1), until the final period where the provisional result was Unsettled (Kp 3).

Solar Radiation: No solar radiation storms were observed. 

Four-Day Space Weather Forecast Summary

Solar Activity: Further Moderate-class flares are likely, with a slight chance of further Strong-class flares, most likely from the most complex region. This risk abates slightly after midweek with the main sunspot group leaving the facing side of the Sun.

Solar Wind /Geomagnetic Activity: No Earth-directed coronal mass ejections feature in the forecast. A recent minor enhancement has been noted. The only other potential enhancement currently possible is that of a very uncertain coronal hole high speed stream later in the period, otherwise, solar winds should remain background. Geomagnetic activity is expected to be mostly Quiet, with a slight chance of G1/Minor storms early day 1 (16 Jul) due to the ongoing weak enhancement. Quiet conditions should then prevail, with a chance of Unsettled or Active spells and a slight chance of G1/Minor storms days 3 and 4 (18-19 Jul).

Energetic Particles / Solar Radiation: No solar radiation storms are expected, with a slight chance of rising in response to any notable flares, mainly from the large off-going sunspot.

Issued at:

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: