Current Shortwave Propagation Conditions

The map below illustrates the current shortwave propagation conditions, using the Maximum Usable Frequency (MUF):

MUF 3000 km Propagation Map, by Andrew, KC2G

The propagation conditions are influenced by several factors, including solar activity, geomagnetic conditions, and atmospheric phenomena.

The solar flux index (SFI) improves high-frequency (HF) propagation³, allowing HF bands⁴ such as the 20-meter and 15-meter to be open for long-distance communication.

Relatively stable geomagnetic conditions are characterized by a low K-index, meaning minimal geomagnetic disturbances. This stability is beneficial for HF propagation, as geomagnetic storms can disrupt radio signals and degrade communication quality. The A-index, which provides a longer-term view of geomagnetic activity, is also low, further indicating favorable conditions for shortwave communication. A K-index higher than 5 may indicate instability in the ionosphere, leading to communication disruptions.

Atmospheric conditions, including ionospheric regions, play a crucial role in HF propagation. The maximum usable frequency (MUF) enables effective communication in higher HF bands ¹ ³ ⁴. However, lower frequencies, such as the 80-meter and 160-meter bands, may experience increased noise levels due to atmospheric disturbances, making them less reliable for long-distance communication.

In general, shortwave propagation conditions favor HF communication, especially on higher frequencies ³. Amateur radio operators and shortwave listeners can expect good signal strength and clarity, particularly during daylight hours when ionospheric conditions are most stable ¹ ².

References:

1. Current Ham Radio Conditions
2. HF Propagation Map.
3. HF Propagation Conditions - Band By Band.
4. HF bands allocated for radio amateurs and their characteristics.