‰ Now 18 WPM transition file follows ‰

With respect to space weather, the past week has been relatively
quiet. Solar activity was very low, the largest flares were several
Class B events, and geomagnetic field activity was quiet to
unsettled, the planetary A index stayed below 10. The Sun did have
some sunspots this week, Regions 884, 885, and 886 dotted the solar
disk, but they werent very active. There are also indications that
old Region 882 may be coming around again. The forecast for the next
several days, Memorial Day weekend, is for continued low solar
activity and quiet to unsettled geomagnetic field conditions. The
probability of major flares or significantly elevated K indices is
low. As a result, there shouldnt be any major propagation surprises.
The 40, 30, 20, and 17 meter bands should provide the bulk of
domestic and DX contacts, but keep an eye out for sporadic E
activity. The format for this contest is everyone works everyone,
with prefixes as multipliers. Although the QSO point structure
favors DX contacts, the fact that prefixes are multipliers means
domestic contacts can play an important role, which in turn means
domestic propagation can play an important role. Being at the end of
May says the probability of sporadic E helping out on 10 meters, and
maybe even on 15, for domestic contacts is quite high. Weve already
had some good sporadic E propagation on 10 and 6 meters in the past
week or two, hopefully it will continue. Look for sporadic E
openings around the late morning hours and then again in the early
evening hours. For true DX contacts, though, 40 and 20 meters will
likely be the bread and butter bands for this contest at solar
minimum. Propagation Tidbit. As we move into summer, well see a
decrease in daytime F2 region MUFs. This is in large part due to a
change in the composition of the atmosphere at F2 region altitudes.
Summer brings decreased ratios of O, atomic oxygen, to O2, molecular
oxygen, and of O to N2, molecular nitrogen. Since the electron
production rate at F2 region altitudes depends on the concentration
of O, whereas the electron loss rate is controlled by O2 and N2, a
decrease in O to O2 and O to N2 ratios leads to lower daytime MUFs
in the summer. Sunspot numbers were 0, 15, 29, 30, 32, 48 and 44
with a mean of 28R3. 10R7 cm flux was 73R3, 75R3, 76R2, 77R5, 83R1,
84R2, and 83R7, with a mean of 79. Estimated planetary A indices
were 16, 8, 7, 7, 8, 7 and 4 with a mean of 8R1. Estimated mid
latitude A indices were 11, 7, 5, 4, 6, 4 and 3, with a mean of 5R7‚

‰ End of 18 WPM transition file ‰