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ARRL Propagation Bulletin ARLP024 (2012)

ARLP024 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 24  ARLP024
From Tad Cook, K7RA
Seattle, WA  June 15, 2012
To all radio amateurs 

ARLP024 Propagation de K7RA

Solar activity was lower this week, although for the past few days
sunspot numbers and solar flux were rising.

Average daily sunspot numbers declined over 14.3 points to 116.1,
and average daily solar flux was off by 14.5 points to 115.9.  There
were five new sunspot groups this week, two each on June 9-10, and
one more on June 13.

The latest prediction has solar flux at 150 on June 15-16, 145 on
June 17-18, 140 on June 19-20, 130 and 120 on June 21-22, 110 on
June 23-26, 105 on June 27-28, followed by a climb back to 120 on
July 1-12.

Predicted planetary A index is 5 on June 15-16, 18 on June 17, 8 on
June 18, and 5 on June 19-25. The next peak of geomagnetic activity
is predicted for June 30 to July 4 with planetary A index at 8, 15,
12, 10 and 8. Following that is a similar peak on July 15-17 of 15,
12 and 8.  Looking further out, planetary A index of 8, 15 and 12 is
predicted for July 27-29.

The geomagnetic forecast from OK1MGW has quiet to unsettled
conditions June 15-17, quiet to active June 18, active June 19-20,
quiet to unsettled June 21, mostly quiet June 22-23, quiet to
unsettled June 24-29, quiet to active June 30, and active conditions
July 1-3.

The most active days over the past week were June 11-12, when the
planetary A index was 14 and 13.  The high latitude college A index
was 22 and 8 on those days, but the mid-latitude A index numbers
from Fredericksburg, Virginia were only 11 and 10.

We often get messages about Cycle 19, the huge solar cycle which
peaked in 1959, but not so often about the peak of Cycle 18.  W7LTQ,
who lives on Fidalgo Island (IOTA NA-065) in the San Juan
Archipelago and signs his messages "Old Chief Lynn" wrote, "Indeed
Cycle 19 was hot, and perhaps even hotter, judging by 10 meter
operations, was Cycle 18! There were a couple of weeks in the spring
of 1948 when the 10 meter phone band was just one howling mess of
heterodynes (AM was king).  During Cycle 19, working the Tucson
local 10 meter 'short skip' net, there were a couple of early
evenings when stations across town in Tucson, AZ, were working short
skip AND long path propagation simultaneously. That was a strange
echo sounding mess. Turning our beams towards a short skip contact
and 180 degrees away confirmed the phenomenon. I think we were
probably on the so-called Grey Line."

Yes, in the days before SSB phone, a pile of AM signals could sound
quite messy.  By the way, 1948 was the year W7LTQ turned 16 years
old. You can have a look at Cycles 18 and 19 and many others on the
WM7D Historical Solar Charts at  Cycles 18 and 19
are the fifth and sixth cycle peaks from the left side of the page
in the chart of "Monthly Sunspot Numbers 1900 to 1999."

Regarding the link in last week's Propagation Forecast Bulletin to
the researcher who believes modern sunspot numbers are inflated, Ken
Grimm, K4XL of Amherst, Virginia wrote, "Regardless of what Prof.
Svalgaard's charts and tables show, those of us who lived through
the late 50s and enjoyed the benefits of something that he thinks
didn't happen, know what we experienced.  Nothing since has come
even close to the conditions on the HF bands during those wonderful
days.  Fifty watts of AM on 10 meters was enough to work the world
with honest 5x9 sigs!  Twenty meters was open 24 hours a day and DX
was commonplace, etc.  Nothing can convince me that the late 50s
weren't unusual!"

An interesting article in the popular press appeared this week,
suggesting that long term prediction of solar cycles is impossible.
Read it at,

Also note toward the end of the article that the student, Bidya
Binay Karak, authored a paper explaining why sunspots disappeared
for a time in 2008-2010.  When I look at his curriculum vitae I see
a paper about the Maunder Minimum, but not about the more recent
quiet Sun. You can check Karak's CV at

Don't miss Carl Luetzelschwab's interesting article in the current
(July 2012) issue of QST, "Our Recent Solar Minimum and Sunspot
Cycle 24 Progress." You'll find it on page 33.

Phil Platt, of the Bad Astronomy blog has a link to a video of an
active sunspot, complete with dramatic music at,

Also check
for a piece on upcoming solar storms.

On June 12, Jeff Hartley, N8II of Shepherdstown, West Virginia
reported, "12 meters has been open to unexpected areas on F2 and
combination Es/F2 paths recently. On the June 9 at 2317 I worked
OM3EY with a S9 CW signal followed by HL2WP S7 at 2321Z. CQs towards
Europe and Asia didn't result in any other contacts. 12 meter
activity is pretty low.

"15 meters has been open all night to the west/NW for EU stations
quite often lately. It was 0041Z (0341 in Latvia) when Alex YL3GAX
answered my CQ, he was S7. Also worked around the same time were
VK5BC on 10 meter SSB, FO8WBB on 12 CW, CT2HTM on 12 SSB, and TA,
JA, DO1, and E70T on 15 SSB. Still the same evening June 10 UTC in
the 0200Z hour on 15, ZL3TE, SU9VB, UR8GZ, EM2012MH, RZ0AF, and
ZL4PW were logged on CW and UA9MA, OE6MDF, SV9ANK, and VK3HF on 15

"Nothing much was happening above 15 meters towards EU on June 10
around 2000Z, but by 2052Z MD0CCE was logged 599 on 12 meter CW
followed by IZ2BHP and G0GKH on 10 CW. Then CQs on 10 SSB resulted
in a run of about 20 EU stations from 2112-2126Z the most distant
being SV2FLM and 9A6JOY. Many Italians and British were logged along
with GM, GW, EI, and F. This was a good Es opening with typical
spotty coverage on the EU end. Quite a few stations were running
100W or less to verticals or low dipoles; they were typically S5 or
less but Q5 with bigger stations mostly S7.

"On June 11 EA7JZ was worked peaking 59 on 10 meter SSB at 2225Z, no
other EU heard or worked. He reported just making 3 LP QSOs with

James French, W8ISS of Lincoln Park, Michigan wrote to ask if there
were any reports of unusual propagation during the recent transit of
Venus event. I did not receive any, nor did I expect them.  But
James got a great response when he set up a public viewing of the
recent transit. He wrote, "had great viewing of the transit here in
Lincoln Park (EN82jg). Helped out at the high school's observatory
with the local astronomy club. Had about 400 turn out as it happened
which was better than I really expected with no publicity that we
were doing it other than a sign out at the road."

Steve Pulley of Stoughton, Wisconsin sent in an SWL report after
copying last week's bulletin from W1AW using BPSK31 over a Radio
Shack DX-392 general coverage shortwave receiver. Looks like perfect
copy, using fldigi, which he read about in an ARRL License Manual.
He was excited, waiting for his ham license in the mail.  I see that
on the same day he wrote, he was issued KC9WDH.

Don't know when we last had a look at this, but note the OVATION
Auroral Forecast at They
display a handy red line indicating the furthest south points where
aurora might be visible after dark.

If you would like to make a comment or have a tip for our readers,
email the author at,

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at For an explanation of the
numbers used in this bulletin, see An archive of past
propagation bulletins is at Find more good
information and tutorials on propagation at

Monthly propagation charts between four USA regions and twelve
overseas locations are at

Instructions for starting or ending email distribution of ARRL
bulletins are at

Sunspot numbers for June 7 through 13 were 98, 90, 107, 127, 114,
132, and 145, with a mean of 116.1. 10.7 cm flux was 128.2, 124.2,
128.3, 128.3, 133.9, 141.3 and 142.8, with a mean of 115.9.
Estimated planetary A indices were 8, 8, 8, 6, 14, 13, and 6, with a
mean of 9. Estimated mid-latitude A indices were 8, 9, 9, 6, 11, 10,
and 7, with a mean of 8.6.


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