2 Solar CMEs May Trigger G1 Storm as Aurora Reaches Northern U.S. on July 23-24
Updated
Updated · Forbes · Jul 23
2 Solar CMEs May Trigger G1 Storm as Aurora Reaches Northern U.S. on July 23-24
1 articles · Updated · Forbes · Jul 23
Summary
NOAA says a G1 geomagnetic storm could begin after dark in North America on July 23-24, giving northern-tier U.S. states a chance to see the aurora.
Two minor coronal mass ejections launched on July 20 and 21 are heading toward Earth; if both interact with the magnetosphere, they could combine into a modest storm, with a 25% chance of G2 strength.
Washington, Montana, North Dakota, Minnesota, Michigan and Maine are among the likeliest viewing areas near the Canadian border, while broader central or southern U.S. visibility is not expected under the base forecast.
Visibility will hinge on cloud cover, light pollution and especially whether the solar wind's Bz magnetic field turns southward; short summer nights and a first-quarter moon may also wash out faint displays.
The UK Met Office issued a similar outlook, saying most ejecta should pass north of Earth but elevated solar wind could still produce a glancing event strong enough for limited aurora sightings.