Overview
- The sun produced a strong M6.9 flare from active region 4513 on Tuesday, which triggered a moderate R2 high‑frequency radio blackout over parts of Africa, Europe and the Arctic.
- NOAA’s Space Weather Prediction Center has issued a G1 geomagnetic storm watch for Aug. 27 and a G2 watch for Aug. 28 because the CMEs from the Aug. 25 eruptions contain Earth‑directed components.
- Early NASA ENLIL model runs show a likely glancing CME encounter around Friday, Aug. 28 at about 6–7 a.m. EDT with an uncertainty window of roughly plus or minus seven hours.
- A positive‑polarity coronal‑hole high‑speed stream is expected to begin affecting Earth around midday Aug. 27 and could push solar wind speeds toward 600 km/s, which may amplify any CME effects.
- Forecasters say the storm’s strength will hinge on the CME’s magnetic‑field orientation — a southward field would increase coupling to Earth’s magnetosphere and could widen aurora visibility while raising risks to HF radio, GNSS signals, satellites and power‑grid operators, so updates should be monitored.