Category Archives: Propagation

Moderate Geomagnetic Storm Watch Issued

The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC) has issued a moderate (G2) geomagnetic storm watch for September 13. A coronal hole high-speed stream, originating from a recurrent, positive polarity coronal hole on the Sun’s surface, prompted the prediction. Minor (G1) geomagnetic storming is possible on September 14.

It’s been a turbulent time on the HF bands over the past several days. On Sunday, September 10, a strong (R3) radio blackout occurred at 1606 UTC. The source, Region 2673, has rotated just around the visible disk. Severe (G4) geomagnetic storm levels were observed at 2350 UTC on September 7, and again at 0151 UTC and 1304 UTC on September 8, due to the effects of a coronal mass ejection (CME).

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Sun Unleashes Monster Solar Flare, Strongest in a Decade

By Sarah Lewin, Space.com Associate Editor


This article was updated at 5:44 p.m. EDT to indicate that a coronal mass ejection was observed coming from the site of the 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).

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