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ARRL Propagation Bulletin ARLP050 (2016)

ARLP050 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 50  ARLP050
From Tad Cook, K7RA
Seattle, WA  December 9, 2016
To all radio amateurs 

ARLP050 Propagation de K7RA

Average daily sunspot number for the past week (December 1 to 7) was
40.9, up 10 points from the previous seven days at the end of

Average solar flux changed hardly at all, moving from 82.6 to 82.2.

Average daily planetary A index dropped from 13.6 to 4.9, and
average mid-latitude A index from 10.3 to 3.4

The latest prediction from NOAA and the US Air Force shows solar
flux at 75 on December 9 and 10, 70 on December 11 to 15, 78 on
December 16 to 18, 82 on December 19 and 20, 86 on December 21 to
27, 84 on December 28 to 31, 82 on January 1, 80 on January 2 and 3,
78 on January 4 to 8, 80 on January 9, 82 on January 10 to 15 and 84
on January 16 and 17.

Their latest projection for Planetary A Index predicts 20, 18, 12
and 8 on December 9 to 12, 5 on December 13 to 17, then 8, 12, 16
and 22 on December 18 to 21, then 30, 12, 10 and 8 on December 22 to
25, 5 on December 26 to 31, then 8, 5, 12 and 15 on January 1 to 4,
20, 18 and 12 on January 5 to 7, 5 on January 8 to 13 and 8, 12, 16,
22 and 30 on January 14 to 18.

Here is a summary of our recent 3-month moving average of observed
daily sunspot numbers, beginning in January 2016 through the end of
November 2016.  The averages were 55.4, 53.5, 49, 45.3, 43.1, 35.4,
33, 33.5, 40, 39 and 29.6.

Monthly average daily sunspot numbers for November were 22.4.  This
is down from 50.4, 37.4, and 29.1 for August through October.

No matter if we observe smoothed 3-month moving average sunspot
numbers or monthly averages the downward trend in activity is
obvious and undeniable.

F.K. Janda, OK1HH sent us the weekly geomagnetic forecast from the
Czech Propagation Interest Group.

"Geomagnetic activity forecast for the period December 9, 2016 to
January 7, 2017

Geomagnetic field will be:
Quiet on December 14 to 17, 29 to 31, January 1
Mostly quiet on December 13, 18, 27 and 28, January 2
Quiet to unsettled on December 11 and 12, 26
Quiet to active on December 9 and 10, 19, 23 to 25, January 3
Active to disturbed on December 8, 20 to 22, January 4

Amplifications of the solar wind from coronal holes are expected on
December 9 and 10 (11, 14 and 15, 18 to 20), January 2 and 3

Remark: - Parenthesis means lower probability of activity
enhancement.  -- F.K. Janda, OK1HH"

And now, this news from Jeff, N8II of West Virginia:

"It has been an interesting couple of weeks on the bands.  The CQWW
CW contest was tough on the low bands and the high bands, leaving
only 20 meters daytime and early evening as a good option.  At
first, a disturbance caused all bands to be poor to EU.  It was not
until Sunday AM on 20 that things really got rolling into northern
Europe and Russia.  My first QSO's with Norway, Sweden, Denmark,
Estonia, and Latvia took place then along with a good number or
Russians.  I could hear several Zone 33 west Africans on 160 well
Saturday night, but they were still working one EU station after
another.  10 was barely open working only Morocco (barely), Brazil,
Argentina, Uruguay, Chile, Venezuela, and Costa Rica and all 3
continental USA zones.

A week later, the ARRL 160 meter test featured good to excellent
propagation.  With low power and limited time I worked all of the
lower 48 states except WY and MT, and 12 DXCC countries including
Ecuador, Costa Rica, EU Russia, Ukraine, Wales, Portugal, Sweden,
and Germany.

Another disturbance started Wednesday with 15 meters being almost
completely closed after good signals the 2-3 days before from the
UK, Germany, Greece, and countries southwest of there along with a
S9 signal from Per, LA8LLA at 1551Z on December 6.

The low bands are finally opening well with some outstanding
signals!  On December 7, starting 0320Z, I worked S9+ 4O/KC0W in
Montenegro, then stations in Lithuania, Latvia, and Slovenia.

But the big excitement was tonight (December 8).  For most of the
last week 3B9HA on Rodrigues Island at a heading of 71 degrees and a
distance of 9770 miles from here has been spotted on 160, but
nothing heard here.  Tonight they were Q5 copy peaking around S9 and
working quite a few USA stations on 160 meters, but I could not
break the pile up.  Right after giving up on 160, I found them on 80
meter CW peaking S9+ 20 dB!  I made an easy QSO at 0110Z.  In all
of years on the bands, I have never heard an Indian Ocean station so
loud on 80 meters.  SFI is 79 and K has been running at 4 since
about noon.  73, Jeff N8II"

This weekend, don't miss the ARRL Ten Meter Contest.  Predicted
solar flux is 70 to 75, and planetary A index is projected to be 18
and 12 for both days.  Last year, the contest was on December 12 and
13, and the solar flux was 116.7 and 122.5, while planetary A index
was 12 and 8.  On December 13 and 14, 2014 solar flux was 159.8 and
166.34, while planetary A index was 9 and 11.  During the 2013
contest (December 14 and 15) solar flux was 164.2 and 156.2, while
planetary A index was 16 and 7.

See contest details at .

The ARRL encourages participants to try a new Web Log Upload app for
this contest.  See details at .

Solar activity is lower this year, but ten meters still offers many
opportunities, and is especially attractive to the "Little Pistols"
(as opposed to Big Guns) contest operators.  For casual operators,
ten meters is especially attractive because of the short wavelengths
(and antenna lengths) involved.

For a half wave antenna cut to 28.3 MHz, that's only 16 feet, 6 and
7/16 inches.  1/4 wave is only 8 feet, 3 inches.  Thus a modest
portable or temporary 10-meter installation can be used.

Here are some simple 10 meter antenna suggestions, some from an ARRL
Facebook post of several years ago.

Take a look at GREGOR, all about a European space weather observatory.

For more information concerning radio propagation, see the ARRL
Technical Information Service at  For an explanation of
numbers used in this bulletin, see  An archive of
past propagation bulletins is at  More good
information and tutorials on propagation are 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 December 1 through 7 were 49, 59, 62, 37, 37,
24, and 18, with a mean of 40.9. 10.7 cm flux was 84.5, 84.4, 84.7,
82.4, 82.7, 79.8, and 77.2, with a mean of 82.2.  Estimated
planetary A indices were 3, 4, 3, 2, 4, 7, and 11, with a mean of
4.9. Estimated mid-latitude A indices were 3, 2, 1, 1, 2, 6, and 9,
with a mean of 3.4.


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