September is a month of dramatic change. High latitude MUFs rise dramatically, bringing the high bands back to life. Nighttime MUF's start to trend lower, bringing improving conditions to the low bands as well. In summer, most of the action is on 20 Meters. Now we will have more options.
Flux levels are too low to expect anything out of 10 Meters this year, but openings on 15 will be common. With solar numbers ranging from the low 70's to around 90, the quality of 15 Meter openings will not be consistent. On some days we may find paths over the pole and to all of Europe. On others, only western Europe (and the QRO guys in East Europe) will be coming thru. The east coast will have better penetration into Russia, and everyone will have limited opportunities over the pole. Seasonally, the polar opportunities will be most common in the early part of the fall DX season. Later this month, the sun will set on the North Pole and high latitude paths will become increasingly difficult as the polar night expands.
DX openings should be more consistent on 17 Meters, since this is a lower frequency. This band will likely serve up the best DX propagation this fall season for day path work. It is a small band, and will easily get crowded when 15 fails to open the European windows. Openings to remote parts of the world (e.g. southern Asia) will be more common on 17 then on 15. A beam on this band would be a real asset over the coming years.
The fall prognosis for 20 Meters is not promising. Nighttime MUF's are falling, and this will close the band in the evening. Night path DX activity will soon shift to the low bands. We may expect deterioration of DX conditions and declining activity through the fall, beginning this month. Watch for the nightly band closing to gradually move to earlier into the evening, shutting down many DX paths we have enjoyed all summer. One opening that should remain reliable is the morning grey line opening to Russia and Europe, with a similar opening to Asia at the end of the day. Paths to the southern hemisphere will also be good, because night paths to the south will be opening up.
The low band season will get off to an early start once evening activity on 20 dries up. 30 Meters will eventually close up at night like 20, but not until later in the season. 40 will become the primary band for night path work, but SSB ops will look for options on 75 because of the special problems of operating 40.