Space Weather Message Code: ALTK08
Serial Number: 23
Issue Time: 2017 Sep 07 2350 UTC

ALERT: Geomagnetic K-index of 8
Threshold Reached: 2017 Sep 07 2350 UTC
Synoptic Period: 2100-2400 UTC
Active Warning: Yes
NOAA Scale: G4 - Severe

NOAA Space Weather Scale descriptions can be found at

Potential Impacts: Area of impact primarily poleward of 45 degrees Geomagnetic Latitude.
Induced Currents - Possible widespread voltage control problems and some protective systems may mistakenly trip out key assets from the power grid. Induced pipeline currents intensify.
Spacecraft - Systems may experience surface charging; increased drag on low earth orbit satellites, and tracking and orientation problems may occur.
Navigation - Satellite navigation (GPS) degraded or inoperable for hours.
Radio - HF (high frequency) radio propagation sporadic or blacked out.
Aurora - Aurora may be seen as low as Alabama and northern California.
Recommendations: Disconnect your antenna if your radio is not in use- to error on the side of caution! 

Below is a summary and few resources to help monitor the current Solar Flare.


Early this morning (Sept. 6), the sun released two powerful solar flares — the second was the most powerful in more than a decade.
At 5:10 a.m. EDT (0910 GMT), an X-class solar flare — the most powerful sun-storm category — blasted from a large sunspot on the sun's surface. That flare was the strongest since 2015, at X2.2, but it was dwarfed just 3 hours later, at 8:02 a.m. EDT (1202 GMT), by an X9.3 flare, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC). The last X9 flare occurred in 2006 (coming in at X9.0).

According to SWPC, the flares resulted in radio blackouts: high-frequency radio experienced a "wide area of blackouts, loss of contact for up to an hour over [the] sunlit side of Earth," and low frequency communication, used in navigation, was degraded for an hour. [The Sun's Wrath:  Worst Solar Storms in History] H/T Space.com

Action items:
Monitor the KP index. If the KP index reaches 6, disconnect your antenna (this is not an exact science. These are our best recommendations).  If you are not using your radio, go ahead and disonnect your antenna(s).
If the KP index appears to be approaching a KP index of 8, you can put your radios in Faraday. It is always best to error on the side of caution.

When will the CME ‘hit’?
Rationale: G3 (Strong) geomagnetic storm levels are likely by
mid-to-late day with the arrival of the 04 CME. G3 conditions are again
likely into day two (07 Sep) due to ongoing CME effects. Day three (08
Sep) is expected to be at mostly active levels with a chance for G1
(Minor) storm levels being reached due to the onset of a recurrent,
negative polarity CH HSS, and any residual CME effects. Solarham.net

Resource Links:

NOAA Index Page

If you have additional information or resources, please leave a comment! Thank you, Polly-01