Tools · Propagation

Space Weather

The sun's mood right now — flux, geomagnetic field, flares, and solar wind, translated for HF operators. Plan the day with the Propagation Planner.

  • SFI feeds the ionosphere: under 90 the high bands sleep; over 150 10m is open coast-to-coast.
  • Kp 0–2 quiet · 3–4 unsettled, weak watery signals · 5+ storm — polar paths die first, but auroral VHF gets interesting.
  • X-ray class is flare activity: C-class barely matters, M-class causes short daytime HF blackouts on sunlit paths, X-class wipes the daytime bands for an hour.
  • Bz south (negative) plus fast solar wind is the recipe for a geomagnetic storm 1–3 days later.