Radio Blackout
D-Region Absorption Prediction — HF radio propagation conditions
Current level
NoneBelow R1
NOAA R scale, from GOES X-ray fluxX-ray fluxB7.1GOES long channel, 0.1–0.8 nm
What it affectsHF radio (3–30 MHz) on the sunlit side of EarthR1 begins at an M1 flare; R3 and above at X1
Global D-RAP
Areas in red/orange indicate high-frequency (HF) radio absorption. Signals passing through these regions may experience degradation or complete blackout.
Polar D-RAP
Polar cap absorption (PCA) events can disrupt trans-polar HF radio communications for days during solar proton events.
Source: NOAA SWPC D-RAP — images refresh every 5 minutes