Solar Conditions
Use solar and geomagnetic readings to determine if HF conditions are favorable.
Solar conditions
Checking cached and live reports
Solar flux (SFI)
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Reading upper-HF support
Trend: checking recent values
F10.7 cm flux
K index
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Reading geomagnetic stability
Trend: checking recent values
Short-term geomagnetic disturbance
A index
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Reading daily geomagnetic background
Trend: checking recent values
Daily geomagnetic activity guide
Sunspots
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Watching active region support
Summed from current active region data
Flare outlook
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Checking blackout risk context
Today's M and X class flare probabilities
What this may mean
Quick interpretation
- SFI: Higher values generally support upper-HF daytime propagation; 120+ is mixed-to-better support in this model, while 150+ is the stronger case.
- K index: Lower is steadier; below 3 is treated as calm, while 4.5 or higher can reduce reliability.
- A index: Lower is quieter; below 12 is treated as calm, while 25 or higher is more disturbed.
- Upper-HF rule of thumb: SFI 150+ with K below 3 and A below 12 makes 20m, 15m, and 10m worth checking first, but path, time, season, latitude, and local noise still decide the opening.