Massive X1.66 Flare Prompts G3 Geomagnetic Watch from SWPC

Wednesday afternoon Active Solar Region 2158 (Beta-Delta-Gamma) produced the first X-Class flare since June 10. The solar region was near the center-line of the Sun and produced a large fast-moving CME that is Earth-directed. As a result, SWPC has issued a G3 (Strong, KP = 7) geomagnetic watch. This, with the long duration flare from earlier this week is a one-two punch providing aurora hunters terrific opportunities to see northern lights between 9/12 and 9/14. Here’s the current solar info graphic from SWPC (Click to see larger image):

SWPC shows three days of geomagnetic watches for 9/12-9/14
SWPC shows three days of geomagnetic watches for 9/12-9/14

Complicated, but Active, Forecast
You can see a G2 (moderate, KP=6) watch posted for 9/12 UTC that starts around 7:30PM EST on 9/11 as the first green bar at the bottom. This is from the long duration M4.57 flare and CME on Monday. The predicted peak of that activity should be between 3:00am – 6:00am EST on Friday morning. As always, there is a +/- of about 6 hours of the arrival of CMEs, so watch the KP values.

On 9/13 there is a G1 watch for the due to potential activity at the beginning of the UTC day as there may be remnant activity from the 9/8 CME. The G3 (Strong, KP=7) watch posted for 9/13 is from the CME from Wednesday’s X-Class flare. That is expected to peak around mid-day UTC – which would be 8:00am EST.

SPWC is predicting the possibility of remnant activity from the X-Class flare CME on 9/14 with their G1 watch. There may be active aurora conditions at the beginning of the 9/14 UTC day – on Saturday evening 9/13 EST.

It should be an exciting three days for Aurora hunters. As always, it is uncertain when exactly the solarstorms will arrive, so monitor the KP closely. You can see live real-time KP values at you can find more even more detailed space weather data at A good way to predict the KP is to watch the Bz component. When it is lower than -5Bt for an extended period of time, higher KP are likely.

If you are going to go out aurora hunting remember the tips in our last minute aurora viewing preparation guid

Happy Hunting!