(YELLOWKNIFE, NORTHWEST TERRITORIES) A G4 (Severe) geomagnetic storm erupted this morning after a gust of solar wind known as a Coronal Mass Ejection slammed into Earth’s magnetic field approximately 15 hours earlier than expected, and with a lot more power than space weather forecasters had predicted.
The impact triggered one the most powerful geomagnetic storms of Solar Cycle 24, an event that peaked at G4 (Severe) near the top of the space weather scales for geomagnetic storms. Similar to hurricanes and tornadoes, geomagnetic storms are classified from G1-G5 by the National Oceanic and Atmospheric Administration.
While it is anticipated the G4 conditions will subside in the coming hours, it is very possible that storm activity will continue Tuesday evening and storm levels may return to G2 or higher overnight. Observers in Yukon, Northwest Territories and Nunavut should be on alert for colourful auroras in the East after sunset, and stay tuned to our Twitter feed as events unfold!