daily · Grid & Utilities

NOAA issues October 11 G2 geomagnetic-storm watch; October 10 G3 warning has ended

The official watch covers two expected coronal mass ejections. NOAA describes possible power-system effects, not confirmed outages or a household electricity-price forecast.

By Greener Numbers Editorial Team · Published October 10, 2026 · Updated 10/10/2026

NOAA's Space Weather Prediction Center issued a G2, or Moderate, geomagnetic-storm watch for October 11, 2026. The October 9 notice says the watch covers the expected arrival of two coronal mass ejections that left the Sun on October 7 and 8. A watch is a forecast of possible conditions, not a report that a utility outage has occurred.

Forecasters said the October 8 ejection was faster and expected it to merge with the slower October 7 ejection on the way to Earth. That is the mechanism described in the dated notice. It does not establish the arrival time or strength at every location.

A separate October 10 notice issued a G3, or Strong, warning through 23:59 UTC that day. That validity window ended at 6:59 p.m. Central Daylight Time on October 10. This brief does not present the expired warning as a current alert. NOAA said the solar-wind environment strengthened after a CME arrived around 14:34 UTC, with G3 conditions beginning at 17:58 UTC.

NOAA's G2 scale says high-latitude power systems may experience voltage alarms and that long-duration storms may cause transformer damage. Its G3 scale says voltage corrections may be required and false alarms may occur on some protection devices. These are possible effects described by the scale, not evidence that a named grid or transformer was affected during this event.

The notices support a dated space-weather forecast and warning history. They do not establish widespread blackouts, actual transformer damage, utility dispatch changes or an increase in household electricity bills. Those claims are not included. Readers should check NOAA's current notices for later updates rather than treating this brief as a live alert feed.

Official source: spaceweather.gov ↗