rjr@mgweed.UUCP (Bob Roehrig) (09/24/85)
qst de k9eui hr propagation forecast bulletin nr 38 from arrl headquarters newington ct september 23, 1985 to all radio amateurs bt if the solar flux continues through the balance of september at levels sustained thus far, there will be a new monthly low for this solar cycle, close to 70. even with the best months for the northern hemisphere, the fall season, now at hand, this would mean little dx on 28 mhz, except on north south paths. considerably greater geographical coverage will be available on 21 mhz but only on daylight paths. even 14 mhz will be primarily a daylight band unless we have much higher flux levels. though propagation is improving on our lower frequencies, dx will become easier on the ears as electrical storms die down as cooler weather spreads over the northern hemisphere. our cold nights bring hot propagation on the lower frequencies except when geomagnetic activity is high. as predicted last week, we have had a rough time with high k and a indices since about september 10. no great improvement in this respect is likely until near the end of september. conditions change rapidly as surges of particles from the sun enter the earths atmosphere. contrary to what we might expect, auroral conditions can be quite severe in the low years of the solar cycle. the current trend toward high and erratic wwv k and a indices is bad news, unless you live in the higher latitudes and enjoy auroral dx on the vhf bands. american sunspot numbers for september 12 through 18 were between 12 and 18 with a mean of 9.1 ar