NOAA issued a G2 (Moderate) Geomagnetic Storm Watch for 09 Oct, and northern lights tonight will depend on how the CME arrives and how far conditions build. The agency said G1 minor to G2 moderate geomagnetic storms are likely on that date.
The watch points sky watchers to the narrow window that matters most: 09 Oct. NOAA tied the forecast to the arrival of a CME associated with an M1.4 flare from Active Region 4549 on 06 Oct.
NOAA Space Weather Prediction Center
The notice came from the NOAA Space Weather Prediction Center and puts the focus on geomagnetic activity rather than a fixed time of day. For readers hoping to see Northern Lights, that means the useful period is the one when the CME’s effects reach Earth and conditions stay elevated long enough for aurora to form.
NOAA’s forecast is not limited to a single storm level. It includes G1 minor and G2 moderate activity, which gives a range instead of one exact outcome, and that range is what observers will be watching as 09 Oct approaches.
Active Region 4549
The flare source matters because Active Region 4549 is not done yet. NOAA said there is a high chance for additional M-class flare activity from Region 4549 in the coming days, adding another layer to the forecast beyond the incoming CME.
For now, the practical takeaway is simple: the date to watch is 09 Oct, the trigger is the CME, and the range runs from G1 to G2. Anyone looking for Northern Lights visibility should focus on the forecasted arrival window rather than the flare time on 06 Oct.
