Warning!

Javascript is disabled on this browser.
Javascript must be enabled for this website to display and function correctly.

Geomagnetic storm forecast - 18th March 2026

What Has Happened?

SOHO LASCO coronograph imagery showing the CME on 16th March 2026. Image: NASA/ESA.

GOES X-ray flux data between 16th - 18th March 2026. Image: SWPC/NOAA.

 

We are expecting an increase in geomagnetic activity between 19th and 21st March due to anticipated arrivals of several coronal mass ejections (CMEs).

The first Earth-directed CME was associated with an M-class solar flare observed at 12:15 UT on 16th March originating from a centrally located active region AR4392. The arrival of this CME is expected late on 19th March and is likely to lead to a significant enhancement in geomagnetic activity, with chances of prolonged STORM periods.

Additional CMEs associated with filament eruptions and another M-class flare occurred on 17th March. The impact of those is not expected to be as severe, however, further STORM periods are anticipated throughout 20th and 21st March.

Last but not least, on the morning of 18th March AR4392 released yet another M-class flare with associated CME. Although further imagery and analysis are required, the arrival of this CME will most likely keep geomagnetic conditions at elevated levels. The probability of geomagnetic activity is also heightened due to the time of year being close to spring equinox.

Assuming clear dark skies, there is an increased chance of seeing the aurora between 19th and 21st March. Those in Scotland, northern England and Northern Ireland have the best chance if the weather is favourable.

 

Sign-up to receive Geomagnetic Storm Forecast emails.

 

Follow us on Twitter:

for more occasional aurora alerts.

for daily space weather forecasts.

 

Glossary

BGS
The British Geological Survey is a geoscience research centre that is part of UK Research and Innovation (UKRI) and affiliated to the Natural Environment Research Council (NERC).

CME or Coronal Mass Ejection
The eruption of a portion of the outer atmosphere of the Sun into space, caused by rapid changes in its magnetic field. Often occurs along with a solar flare.

Filament Eruption
An eruption of solar plasma (i.e. ions and electrons) associated with the upward movement of solar magnetic field lines into the corona. Filaments are usually dark against the bright solar disk but can appear bright (as 'erupting prominences') on the limbs of the Sun against the darkness of space. Filaments are often associated with CMEs

Solar Flare
Energy released by the explosive reorganisation of magnetic fields within the Sun's atmosphere.

Sunspot/Active Region
A region of intense magnetic field in the Sun's visible outer atmosphere often associated with flares and CMEs.