The National Oceanic and Atmospheric Administration (NOAA) Space Weather Prediction Center (SWPC) has issued a G2 geomagnetic storm warning for March 19 due to the possible influence of a coronal mass ejection (CME). Geomagnetic storms are classified using a G scale, which ranks their intensity from G1 (minor) to G5 (extreme).
This is good news for aurora chasers that the predicted G2 level storm could bring northern lights as far south as New York and Idaho, but NOAA’s SWPC says there is a chance G3 levels could be reached, which could lead to auroras being observed deep into mid-latitudes such as Illinois and Oregon.
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Seasonal boost to northern lights
This week’s storm watch comes at a particularly exciting time for northern lights hunters, with many regarding March is one of the best months to see the Northern Lights.
Around the spring and autumn equinoxes, the Earth’s orientation in space makes it easier for the magnetic field to connect to the magnetic field carried by the solar wind and incoming CMEs. This seasonal increase in geomagnetic activity is known as the Russell-McPherron effect, first described by geophysicists Christopher Russell and Robert McPherron in 1973.
During the equinox, the sun shines directly above the Earth’s equator, giving both hemispheres equal day and night. This geometry also helps incoming solar wind interact more effectively with the Earth’s magnetic field.
Most of the year, Earth‘s tilt reduces this interaction, helping to deflect some of the incoming charged particles. But around the equinox, the natural shield becomes more open to the incoming solar wind. As a result, space weather events such as fast solar wind from coronal holes or CMEs can have a stronger impact, increasing the chances of auroras.
Follow along!
Stay up to date with the latest space weather news with our aurora forecast live blog. For real-time forecasts based on your location, consider using a space weather app. A great alternative is “My Aurora Forecast & Alerts” (available for iOS and Android). For a deeper dive into space weather conditions, “Space Weather Live” is another excellent choice (available for iOS and Android)






