What is the difference between
Global versus Regional HF propgation conditions
Global HF propagation conditions refer to the overall state of high frequency radio propagation across the entire planet. It is used to make broad predictions about the potential for wolrdwide communications.
Solar activity, and space weather influence these conditions.
Figure 1: A banner courtesy of Paul L Herrman, N0NBH
On the other hand, regional HF propagation conditions refer to the state of radio frequency propagation within a specific geographic region. These conditions can vary widely. Regional HF propagation conditions are often more important to individual operators, as they can have a significant impact on the success of communications within a specific area.
An example showing how the regional conditions vary from the globally calculated values shown in Figure 1:
Figure 2: Online T Index Map courtesy of ASWFC; Updates every 15 minutes
Click on Figure 2 to read explanations.
In general, global HF propagation conditions provide a broad overview of the state of the HF bands, while regional HF propagation conditions provide a more detailed picture of the conditions that individual operators are likely to experience. Both types of conditions are important for amateur radio operators and shortwave listeners, as they help to guide frequency selection and other operational decisions.See for example an animated review of regional conditions over the recent 24 hours:
Figure 3: Animated MUF 3000 km propagation map in the last 24 hours courtesy of Roland Gafner, HB9VQQ
shows near-real-time indices and explains what the terms mean.