[South Florida DX Association] ARLP021 Propagation de K7RA

[bmarx at bellsouth.net]

> 
> SB PROP ARL ARLP021
> ARLP021 Propagation de K7RA
> 
> Solar flux values and sunspot numbers were higher over the past
> week. Average daily sunspot numbers rose nearly 65 points to 113.6
> from the week earlier. Average solar flux rose over 18 points. The
> sunspot number reached a peak of 148 and 147 on Sunday and Monday,
> May 16-17. This was due to the growth of sunspot 609, which expanded
> dramatically along with a host of other spots.
> 
> A medium sized sunspot group is on the sun's far side, as detected
> by helioseismic holography. There were some unsettled conditions
> last Thursday, May 13, but the rest of the week was quiet with low K
> and A indices.
> 
> We are currently within a weak stream of solar wind from a coronal
> hole, so some resulting geomagnetic activity is possible. The
> predicted planetary A index for May 21-24 is 15, 15, 12 and 10.
> Solar flux should stay around 100 over the next week.
> 
> We are moving into late spring, with the longest day of the year
> just one month away. As the days become longer, we'll notice
> worldwide openings on 15 meters are not as common as they were
> earlier in spring. Worldwide 40-meter openings will come later in
> the evening, as the hour of sunset advances.
> 
> Users of lower frequencies, which depend on darkness for long
> distance communication, may notice shorter duration openings through
> the night because there are less hours of darkness. Seasonal noise
> levels should begin to rise as well.
> 
> Solar numbers aren't holding up too badly, considering where we are
> in the current cycle. Note that the average sunspot number this week
> at 113.6 is higher than the same week a year ago, when it was only
> 83.6. However, two years ago it was 160.3 and a year prior to that
> it was 122.3. There are still good openings in store for us, but the
> frequencies used will be lower, and except for some sporadic-E skip,
> we won't see the exciting 10 meter propagation we did a few years
> back.
> 
> Sunspot numbers for May 13 through 19 were 107, 98, 117, 148, 147,
> 91 and 87 with a mean of 113.6. 10.7 cm flux was 100.8, 109.6,
> 115.3, 118.3, 111.1, 107.8 and 108.8, with a mean of 110.2.
> Estimated planetary A indices were 13, 8, 9, 4, 5, 4 and 6, with a
> mean of 7. Estimated mid-latitude A indices were 17, 4, 7, 4, 3, 4
> and 6, with a mean of 6.4.
> NNNN
> /EX
> 
>