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ARRL Propagation Bulletin ARLP050 (2015)

ARLP050 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 50  ARLP050
From Tad Cook, K7RA
Seattle, WA  December 11, 2015
To all radio amateurs 

ARLP050 Propagation de K7RA

Australia's Space Weather Services issued a geomagnetic warning at
0132 UTC on December 9. It said that due to solar wind from a
coronal hole, expect increased geomagnetic activity on November 10.
Both average daily solar flux and average daily sunspot numbers were
higher over the December 3 to 9 period than on the previous week.
Average daily sunspot numbers increased from 41.6 to 48 and average
daily solar flux rose from 97.2 to 102.2.
Geomagnetic indicators rose at well, with planetary A index rising
from 9.9 to 12.6 and mid-latitude A index from 6.6 to 11.1.
Predicted solar flux for the near term is 112 and 115 on December 11
and 12, 120 on December 13 to 15, then 115 on December 16 and 17,
105 on December 18, 100 on December 19 to 26, 98 on December 27, 95
on December 28 and 29, 98 on December 30, 100 on December 31 and 105
on January 1 and 2, 100 on January 3 and 4 and 105 on January 5 to
Predicted planetary A index is 22, 16 and 12 on December 11 to 13,
then 10, 6, 10 and 6 on December 13 to 15, then 10 and 8 on December
16 and 17, 5 on December 18 to 26, then 18, 15 and 10 on December 27
to 29, and 5 on December 30 and 31, then 15, 20, 18 and 10 on
January 1 to 4, then 8, 12 and 10 on January 5 to 7, and 8 on
January 8 to 11.
Today we have an updated geomagnetic forecast from Petr Kolman,
OK1MGW of the Czech Propagation Interest Group. OK1MGW and OK1HH
have made these weekly forecasts since 1978, 37 years!
Petr expects quiet to active geomagnetic conditions on December 11,
quiet to unsettled December 12, mostly quiet December 13, quiet to
active December 14 and 15, quiet to unsettled December 16, quiet
December 17 to 22, mostly quiet December 23, quiet to active
December 24 and 25, quiet to unsettled December 26 and 27, active to
disturbed December 28, quiet to unsettled December 29, mostly quiet
December 30 and 31, quiet to active January 1 to 3, quiet to
unsettled January 4, and quiet to active again on January 5 and 6.
He expects increases in solar wind on December 11, 14 and 15, 24 and
25 and January 1 to 3 and 5 and 6.
So far this year we have an average daily sunspot number of 71.2,
and by December 31 that average will probably not deviate much,
because the 71.2 figure is based on 94 percent of the data we will
have by the end of the day on December 31.
The average daily sunspot numbers for the years 2008-2015 were 4.7,
5.1, 25.5, 80.1, 82.3, 97.1, 121.2 and 71.2, with the last figure
being a preliminary value. Cycle 23 had a peak year in 2001 at
176.7. The two previous years (1999-2000) each had a yearly average
of daily sunspot numbers above 170 (173 and 170.3). So the peak of
the previous cycle had much higher sunspot numbers, plus the peak
was sustained over several years.
We finally received a couple of reports from participants in the CQ
World Wide CW DX Contest a couple of weeks back, from N8II and NK8Q.
First from Mark Schreiner, NK8Q in State College, Pennsylvania
reporting on December 4:
"I only operated for a few hours from mid-afternoon (2000 UTC) on
Sunday until the end of the contest at 2400 UTC. 10m was open okay
at that time and I put quite a few stations in the log, then moved
to 15m to continue doing the same. It was open better than 10m and I
mostly managed to work stations into South America on both bands,
but also the farther reaches of North America as well. I finished
off with 20m for the last 60-90 minutes with most of the contacts
during that time into Japan. It is always fun having a run in the
log to JA-land!
I'm looking forward to the 160m contest this weekend (this was
written on December 4, so the 160 meter contest was actually last
weekend, December 5-6). I did a quick check of the antenna
(Inverted-V, I sure miss my Inverted-L from my old QTH!) at the
clubhouse of Nittany ARC just outside of State College, Pennsylvania
last night to make sure it was still functional (last year was the
first year it was functional since I moved to this area about 5
years ago).
I didn't have time to check the Beverage antenna we deployed last
winter, but may do so on Saturday with some daylight to get its
advantage into EU on Saturday night. I have to work until 2200 UTC
and then have dinner with my XYL, but plan to spend most of the
night at the clubhouse to operate for the evening and at least until
0800 UTC.
Saturday night I can't get on until much later due to a surprise
birthday party but afterward I'll be on the air until at least 0800
UTC again. I'm hoping conditions are favorable for others to hear my
QRP signal as I've done in the past!"
Uh-oh Mark. Now that this bulletin has been read all over the world,
is that birthday party still a surprise? I guess so, since it
actually happened last week.
Now, about 94 miles directly south of NK8Q, a report from occasional
contributor Jeff Hartley, N8II in Shepherdstown, West Virginia:
"Here is a brief summary of CQWW CW from here.
160 M: It was not a good weekend for those short of super station
level, there seemed to be a lack of Caribbean signals as well as
weak EU, but I did manage 9A (Croatia), OZ1IKY (the EU leader it
appears, in Denmark), S5 (Slovenia), DL (Germany), OM (Slovak
Republic), and EI (Ireland) the first night, but the second night
was worse.
80M: Conditions were okay, but EU stations were not loud around 0300
UTC the first night, then quite good by 0430-0530 UTC including
northern EU and Russia. 4X (Israel) and TC0A in Turkey were logged.
JA3YKC was heard but weak around Saturday sunrise.
40M: Plenty of EU activity through the night until I had to QRT both
days, zone 14 weakened around 0300-0400 UTC the first night. It was
surprising that EU did not drop out around 0200- 0400 UTC. Even the
second night, EU activity kept the band crowded with many S9+
signals. I worked 4X, A7 (Qatar) and 7Z1 (Saudi Arabia) in the
Middle East and 3D2 (Swaziland) and JA around Sunday sunrise.
SU90IARU (Egypt) was my only Zone 34 QSO of the contest. I did work
all zones on all bands. Several multi-op stations claimed all zones
on 40 and 20 M as did W3LPL on 15M.
20M did not disappoint at the start with the band open to some
degree in all directions; I made WAC including DP1POL in Antarctica
in the first 17 minutes!
AF (Africa) signals were loud, logging all AF zones except 34 and 39
by 0130 UTC. HS, JT, BV and BY were logged within the same 10
minutes. Signals were loud from EU and Zone 17 (Asiatic Russia)
around sunrise and again from 1800-2000 UTC. The northern EU
stations were loud from 2100 UTC right through 0100 UTC Saturday
evening along with East and some central Asians. I logged 37 Zones
total missing 30, 34, and 39.
15M: Wow the Europeans, worked almost a thousand QSO's total during
my 24 hour total effort!  Both days featured good openings to EU
Russia, but I never logged 17 just beyond the UA4 stations that
called. Northern EU was in Saturday afternoon until at least 22Z via
probable auroral Es and also on 20 M as noted. Saturday evening I
worked YE1K (Indonesia), BY, DS4, 9M6NA and AH0K along with loud
10M: I made only 223 QSO's vs. 915 last year. The band opened to EU
both days, but almost entirely southern and western EU, never
hearing zone 16. All of the AF zones except 34 were present and loud
around 1645Z Sunday working 5R, ZD8, C92, D4, and three ZS stations.
The band never opened well to the northern Caribbean while I was
active due to the declining solar flux. Time spent there was
interesting, but the Pacific and JA were tough.
Overall the low K index and solar flux around 100 provided very
decent conditions except on 10 and 160 meters. The northern EU
stations were treated to a great weekend compared to averages in
73, Jeff N8II"
Thanks, Jeff! Great report.
Don't miss the ARRL 10 Meter Contest this weekend. Although solar
activity isn't high, this contest is scheduled to take advantage of
ionization from meteor trails during the Geminids meteor shower.
This year the peak of the shower should be late in the contest.
Look here for details:
Note all the multipliers in Mexico you can work:
Check this for rules and details:
Back in the November 30 propagation bulletin, ARLP048, we mentioned
Don, W9IXG and problems on 75 meters with his local/regional
network. (
I suggested that solar activity is low enough that it may not always
support regional communications on 75 meters. In other words, the
ionosphere directly overhead is not energized enough to reflect
signals back to stations below.
Ted Leaf, K6HI of Kona, Hawaii suggests switching to 40 meters when
75 meters isn't working.
Ted wrote, "I am on our ARMY MARS net on 40, and it works well
across all the islands. Our antenna heights on 40 are NVIS." In
other words, he uses antennas on 40 meters that are low enough to
support Near Vertical Incidence Skywave propagation.
Note that via links at the bottom of the page you can navigate back
to page 1, or out to page 8 and beyond for more information on NVIS
antennas and propagation.
W9IXG replied:
"Thanks for the recommendation. We will investigate using 40m during
radio blackout conditions on 75m. Our net runs from 1100-1315 UT so
finding an open frequency for that length of time could be a problem
and I'll need to poll our 100+ members to see how many have access
to 40m.
Our NWS weather net has been operating since 1964 on 75m and while
we have seen short periods of time when we've had no propagation,
we've never experienced several continuous months of poor-terrible
conditions. That being said, conditions do seem to be improving as
we move into the winter."
David Moore wrote:
"The sun is supposed to be entering a quiet period, but it's still
showing signs of its 11-year peak of activity it reached in early
Always good for tips on aurora, David also sent this link concerning
widespread observation of Aurora Borealis in both North America and
Europe recently:
David also sent this:
Dennis Markel, N1IMW of Bedford, New Hampshire wrote:
"As you predicted, the ARRL 160 Meter Contest enjoyed very quiet
conditions both nights - noise was at S1 to S2 on my FT1000mp here
in Bedford.
Similar conditions existed for the CQ World Wide on 160 meters as
For more information concerning radio propagation, see the ARRL
Technical Information Service at For an explanation of the
numbers used in this bulletin, see An archive of past
propagation bulletins is at More good
information and tutorials on propagation are at
My own archives of the NOAA/USAF daily 45 day forecast for solar
flux and planetary A index are in downloadable spreadsheet format at and .
Click on "Download this file" to download the archive, and ignore
the security warning about file format. Pop-up blockers may suppress
the download.
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 December 3 through 9 were 47, 25, 41, 38, 50,
58, and 77, with a mean of 48. 10.7 cm flux was 94.5, 97.6, 100.5,
102.2, 100.7, 111.2, and 108.8, with a mean of 102.2.  Estimated
planetary A indices were 4, 5, 16, 24, 20, 11, and 8, with a mean of
9.9. Estimated mid-latitude A indices were 3, 4, 14, 26, 16, 9, and
6, with a mean of 6.6.


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