Overview
- A burst of solar activity from sunspot region 4455 produced three strong flares, including an X1.0, and launched multiple coronal mass ejections that are now en route to Earth.
- NOAA’s Space Weather Prediction Center has issued a G2–G3 (strong) watch for June 4–5 with isolated G4 (severe) intervals possible as the multiple CMEs arrive.
- If the forecasted G3–G4 activity occurs, the auroral oval could expand into mid‑latitudes, potentially making northern lights visible across as many as 23 U.S. states and parts of the U.K.
- Short-term timing and intensity remain uncertain because the outcome depends on the interplanetary magnetic field orientation (Bz); DSCOVR’s real‑time solar wind data typically provide only about a 30‑minute practical lead time.
- Agencies warn of tangible hazards for people and systems: geomagnetic storms can disrupt HF radio, GPS navigation, satellite operations, power grids and increase radiation risk for astronauts, and observers should monitor official updates and local weather before heading out.