The geomagnetic storm watch for the 6 and 7 September, 2017 UTC-days has been upgraded to G3 (Strong). The G3 Watch is in anticipation of the expected arrival of a coronal mass ejection (CME) that took place in association with an M5 flare (R2-Moderate radio blackout) observed on 4 September at 2033 UTC (1633 ET). Current analysis and forecasts reflect CME arrival late on 6 September, 2017; with CME effects continuing into 7 September. Keep checking our SWPC website for updates to the forecast.