Maximum Usable Frequencies (MUFs) for 3,000 kilometer radio signal paths Near real time map generated by Proplab-Pro www.spacew.com How to determine the MUF? 1.- For 3,000 kilometer paths: find the midpoint (or half-way point) of the path and read the labelled MUF contour value at that point. All contours are given in MHz. 2.- For 4,000 kilometer paths: follow the previous rule and multiply the given contoured MUF values by 1.1. 3.- For longer path lengths: divide the path into equal 3,000 or 4,000 km segments and compute the MUFs corresponding to the two midpoints that are 1,500 or 2,000 km from each end of the path. Then select the lower of these two MUFs.
                        HF PROPAGATION If your area of the world is highlighted then we could most probably contact on the selected band. Change band and UTC if desired.  Current Sunspots (view from earth) Latest Cycle 24 Sunspots Number Prediction
D-Region Absorption Prediction
D-Region Absorption Prediction Conditions in the D-Region of the Ionosphere have a dramatic effect on High Frequency (HF) communications and specially on its lower bands (160m, 80m, 40m  and 30m bands) where D layers are responsible for the absortion of radiosignals during daytime. The map depicts the D-region at high latitudes where it is driven by particles as well as low latitudes, where photons cause the prompt changes Sunspots are cooler areas on the solar surface. Although sunspots themselves produce only minor effects on solar emissions, the magnetic activity that accompanies the sunspots can produce dramatic changes in the ultraviolet and soft x-ray emission levels. These changes over the solar cycle have important consequences for the Earth's upper atmosphere and the Ionosphere. A solar flare releases energy than can affect HF propagation: 1. ionizing radiation that arrives at earth immediatly; 2. a shockwave riding along the solar wind; 3. dense particles behind the shockwave that arrives two to three days after the flare. Solar flares expose earth to increased ionization radiation, possibly temporarily raising the MUF This chart depicts the progression of the Solar Cycle. The charts and tables are updated by the Space Weather Prediction Center monthly using the latest ISES predictions. Observed values are initially the preliminary values which are replaced with the final values as they become available Are Sunspots forecasts reliable? Well, they used to be quite reliable but with the new Cycle 24 things are changing. Click here to compere how previous Cycle 24 forecast compare.
Solar Flux
Solar Wind and Magnetic Field

EA5DY/4: Propagation Forecast for
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