August 1997 Forecast -- Flux Range 70 - 97

by Roy, AD5Q - Houston, Texas

It is past mid-summer, and the weather is still hot and humid here in south Texas. Equinox time is only six weeks away, and with the low sunspot activity this means an early transition to lowband season.

Conditions on 20 are starting to change. Nighttime paths are beginning their deterioration, with fewer signals on in the evening. The grey line will be aligning itself over the pole. In recent months, we have enjoyed good morning conditions into Asia because the grey line has lead in that direction.

Another summertime phenomenon is the thinning of the ionosphere due to overheating by the sun. This has the beneficial effect of lengthening the DX window to Asia in the morning on 20, but at the peak of the cycle it closes 10 Meters for high latitude DX work and attenuates openings on 15. These are not problems for us now, since 10 & 15 are dead anyway. This overheating effect (and I don't have a proper technical name for it) dissipates during August and September and daytime MUFs begin to rise. 15 Meter operators can look forward to improved conditions in October.

Meanwhile, the morning pipeline to Asia will deteriorate, as will the late afternoon path to Europe. These were greyline paths. The good news is that daytime propagation in these directions is improving. Europeans are workable throughout the day on 20, but most of the signals are from the better equipped stations. Daypath signals are stronger the closer you are to the DX (i.e. the East Coast can work the weaker Europeans and we can't). We still get an EU propagation peak in the late afternoon, but this will shift to the morning when the transition to lowband season is complete. Asian daypath propagation begins in the afternoon after the Japanese sunrise, and continues through the evening. After dark, nightpath propagation remains good to the Pacific and Australia. Africa is good in the afternoon and evening, and the repositioned grey line path over the pole will bring Siberia and Central Asia in nicely both in the morning and early evening.

Evening DX activity is already moving back to 40, which is in excellent shape. Signals from the weaker stations can be heard amidst the static crashes, and the high summer QRN level remains the most serious problem. This is especially true here in Texas, where the end of summer is stormy and also the peak of hurricane season. The 40 Meter opening to Europe lasts through the evening, with good signals from many parts of Russia. Asia comes in throughout the early morning with a peak after sunrise. We can look forward to improved conditions with lower QRN levels, though in winter these DX windows are shorter due to lower nighttime MUFs.

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