Moving into summer, we can expect 10 meter DX to be very sparse, and 20 to be excellent as a nighttime band. This is the time for our seasonal peak on 15 Meters, but due to lower fluxes, conditions probably won't be as good as last year. Last summer we had very high solar fluxes, and 15 took on many of the nighttime properties of 20. The 15 meter season extended itself into July, and August wasn't bad either.
Normally I don't follow the fluxes much, but the quality and duration of our 15 meter season depends on them. Nowadays fluxes in a typical month are ranging from about 120 to 200. When they are at the lower end of this range, the band will close earlier in the night and we will lose, for example, the sunrise sweep across Europe. When the fluxes swing to the high end of this range, we will get phenomenal EU/USSR openings at night and during much of the day. In short, 15 meter propagation will vary, depending on the solar numbers. Our summer season this year will be much like in 1988, and not like '89.
In '88, we still had strong openings to the Far East in late morning with lots of SSB activity from Indonesia in particular. We had long path in the morning, but not every day. Conditions were excellent into June, but didn't last through the summer. Nighttime propagation faded, and we were left with a the low MUFs across the daytime paths. There were, therefore, no good DX bands during the day.
This season we should keep an eye on the flux numbers for 15 meter propagation. Fluxes are plenty high enough to keep 20 open all night, so we will have this band to fall back on when 15 isn't working - but only at night. We will also have the 20 meter morning stuff to the Far East, with the Indian Ocean and southern Africa via long path.