Space weather forecasters have issued a Severe (G4) Geomagnetic Storm Watch for the evening of Friday, May 10. Additional solar eruptions could cause geomagnetic storm conditions to persist through the weekend. This severe geomagnetic storm includes the potential for aurora to be seen as far south as Northern California.
G4 conditions were observed by SWPC around 9:37 a.m. today and significant to severe geomagnetic storming is likely to continue.
During a press call this morning, experts with NOAA’s Space Weather Prediction Center (SWPC) – a division of the National Weather Service – confirmed the likelihood of the geomagnetic storm. The cause are solar flares and coronal mass ejections (CMEs) began on May 8 from a sunspot cluster that is estimated to be 16 times the diameter of Earth.
Snap a photo of the northern sky
You may not be able to see an aurora with the naked eye tonight, but your phone might! Find a dark area with a good view of the north and take photos of the night sky with your phone camera, “you might get a nice surprise,” one of the experts said.
The timing of the possible aurora is somewhat uncertain. Generally, the best aurora viewing is usually within an hour or two of midnight (between 10 PM and 2 AM local time). These hours of active aurora expand towards evening and morning as the level of geomagnetic activity increases. There may be aurora in the evening and morning but it is usually not as active and therefore, not as visually appealing.
A large sunspot cluster has produced several moderate to strong solar flares since Wednesday at 5:00 am ET. At least seven flares were associated with CMEs that appear to be Earth-directed. SWPC forecasters will monitor NOAA and NASA’s space assets for the onset of a geomagnetic storm.
CMEs are explosions of plasma and magnetic fields from the sun’s corona. They cause geomagnetic storms when they are directed at Earth. Geomagnetic storms can impact infrastructure in near-Earth orbit and on Earth’s surface, potentially disrupting communications, the electric power grid, navigation, radio and satellite operations. SWPC has notified the operators of these systems so they can take protective action. Geomagnetic storms can also trigger spectacular displays of aurora on Earth. A severe geomagnetic storm includes the potential for aurora to be seen as far south as Alabama and Northern California.
GPS and power grids possibly affected
GPS satellites may experience more frequent and longer degradation possible. In other words, do not follow your GPS directions blindly.
In California the Cal ISO is fully aware of the geomagnetic disturbance event (GMD) and is following their Reliability Coordinator Geomagnetic Disturbance (GMD) operating plan. Spokesperson Anne Gonzales replied to our query: “RC West (the grid reliability coordinator across the West) is already following this GMD procedure. We have notified the balancing areas and transmission operators about the GMD warning, and scheduled conference calls to coordinate any actions needed.”
Per PG&E spokesperson Paul Moreno, “Our Electric Systems Operations team, who operate the transmission and distribution electric grids, are fully aware of the National Oceanic and Atmospheric Administration warnings for a Geo-Magnetic Disturbance (GMD) and continuously monitor the system to be ready to respond to any impacts. The potential May 11 GMD will primarily affect areas north of PG&E’s service territory.”