A G3-level magnetic storm, which began on March 20 at around 23:00 Moscow time, ended after noon on March 21. This was reported by Mikhail Leus, a leading specialist at the "Fobos" weather center. The storm became the strongest since late January 2026, according to an assessment by the solar astronomy laboratory of the Space Research Institute of the Russian Academy of Sciences and the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences. The geomagnetic field remains in a disturbed state until the first half of Monday, with weak and short-lived intensifications up to the level of a minor storm possible. A full normalization of conditions is expected on Tuesday.
The second plasma cloud has reached Earth: the calm is deceptive
At least one more plasma cloud has reached Earth. The total induction of the interplanetary magnetic field has risen to 40 nanoteslas, while the threshold for extremely high values begins at 25 nT.
Scientists from the Space Research Institute of the Russian Academy of Sciences and the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences warn that the apparent calm on the magnetic storm chart is deceptive. In the next 2-3 hours, a second surge of auroras is possible, potentially stronger than during the night of March 20-21.
Geomagnetic conditions forecast for March 21-24
- Current state: disturbed, the G3 storm ended after noon on March 21
- Through the end of March 21 and on Sunday: weak storms are possible
- First half of Monday: disturbed conditions will persist
- Tuesday: full normalization
- Second plasma cloud: has already reached Earth, a new surge of auroras is possible in the coming hours
- Interplanetary field induction: about 40 nT (the threshold for extreme values is 25 nT)
A G3 storm is the third strongest level out of five possible. Such events affect power systems at high latitudes, create problems for satellite navigation, and disrupt high-frequency radio communications. During G3 storms, auroras are observed at the latitudes of St. Petersburg and northern Siberia. If the second plasma cloud triggers a stronger surge, the visibility zone of the auroras may shift farther south.
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