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ARRL Propagation Bulletin ARLP052 (2016)

ARLP052 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 52  ARLP052
From Tad Cook, K7RA
Seattle, WA  December 23, 2016
To all radio amateurs 

ARLP052 Propagation de K7RA

Over the past reporting week (December 15-21) solar activity was
little changed from the previous seven days, although on two days
(December 16-17) there were no sunspots. Average daily sunspot
numbers declined two points from 13 to 11, and average daily solar
flux bumped up one point to 73.2.

Average planetary A index changed from 13.3 to 7.9, and average
mid-latitude A index from 9 to 5.7.

The outlook for the next month shows daily solar flux in a big
downward adjustment for the next week, compared to the forecast in
yesterday's ARRL Letter. The average predicted solar flux Wednesday
on December 23-28 was 84.2, but in Thursday's forecast it dropped
suddenly to 62.

Predicted solar flux is 73 on December 23-24, 72 on December 25-29,
77 on December 30-31, 79 on January 1-3, 77 on January 4-5, 75 on
January 6-10, 77 on January 11-12, 75 on January 13-14, 73 on
January 15-17, 75 on January 18-23, 77 on January 24-27, 79 on
January 28-30 and 77 on January 31 and February 1.

Predicted planetary A index is 12 on December 23-24, 8 on December
25, 5 on December 26 through January 1, then 8, 10, 20, 22, 16, 14
and 6 on January 2-8, 5 on January 9-13, 10 on January 14, 15 on
January 15-16, 25 and 28 on January 17-18, 12 on January 19-20, 8 on
January 21, and 5 on January 22-28.

From Australia's Space Weather Services:

"Subj: SWS Geomagnetic Disturbance Warning 16/57
Issued At 0002 UTC/22 December 2016
By the Australian Space Forecast Centre.

"The effect of a high speed solar wind stream from a coronal hole is
expected to keep the geomagnetic activity enhanced from 22 to 24
December. Minor storms may be observed throughout this period with
the possibility of some major storm periods on 22 and 23 December.


22 Dec:  Active to minor storm, some major storm periods possible
23 Dec:  Active to minor storm, isolated major storm periods possible
24 Dec:  Unsettled to active, isolated minor storm periods possible"

We also have the weekly geomagnetic prediction for December 23 to
January 18 from F.K. Janda, OK1HH of the Czech Propagation Interest

"Geomagnetic field will be:
Quiet on December 30-31, January 1, 8-11
Mostly quiet on December 27-28, January 2, 12, 15-16
Quiet to unsettled on January 2-3, 14, 29
Quiet to active on December 23-26, January 4, 6-7, 13, 17
Active to disturbed on January 5, 18

"Increases in solar wind from coronal holes are expected on December
23-25, January 3-8, 17-18."

W4KUT's comments on Cycle 19 in last week's Propagation Forecast
Bulletin ARLP051 drew quite a response.

Jon Jones, N0JK wrote:

"Interesting comments from W4KUT regarding Solar Cycle 19.

"I have heard from 6M ops who were active during Cycle 19 of daily
North America coast to coast F2 contacts on 6M with just a few watts
on AM and indoor dipoles during the Fall and Winter months. With the
higher F2 MUF, 6 meter contacts also occurred from the Midwest to
New England and California via F2.

"International DX was limited due to many countries, particularly in
Region 1, not having a 50 MHz allocation. The IGY, however, gave
special permission to a few operations from Region 1, so a number of
stations completed WAC on 50 MHz during Solar Cycle 19.

"This was a comment regarding Cycle 19 in 1957 from the UKSMG
regarding 6 meters from Japan.

"During the peak of Cycle 19, the fall DX season of 1957, North
America was coming in every day to Japan (on 50 MHz). At the same
time, VE (Canada), KL7 (Alaska), and KH6 (Hawaii) signals were also
heard every day. On October 9, 1958 - JA3CE and CT3AE (Madeira
Island) had a QSO establishing the new record via long path for 50
MHz of over 25,000 km."


"Jon, N0JK"

KH6CJJ wrote:

"My novice license was issued in 1957.  As a novice I was limited to
CW with crystal control and had only one or two crystals in the 15
meter novice band.  As I remember, one was around 21.175.  In the
evenings, I would hear VKs and ZLs operating AM around that
frequency with great signals.  I started calling them on CW and
worked many cross mode.  My 60 watt signal was loud enough there to
cause them to see who was calling, even though I was many kilocycles
away and on CW.

"I got my Conditional (General for those who did not have access to
an FCC examination office) license in 1958.  Band conditions were so
good that in the Fall and Spring I would cause big pileups of
Europeans on 15 while running 40 watts AM with my Heathkit DX-35.
Europe is the toughest place to work from Hawaii and I have never
had the same pileups ever since, even running more power on SSB with
a better antenna.

"PS - I enjoy your propagation bulletin every week...keep up the
good work!

"Kent Carlson KH6CJJ Maui Hawaii"

Max White, M0VNG sent this article about activity at the core of the

Here is an article from the Chinese Academy of Sciences regarding
sunspot helicity, which I had not heard of.

Helicity definition:

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
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 15 through 21 were 12, 0, 0, 13, 12,
25, and 15, with a mean of 11. 10.7 cm flux was 72.5, 72.6, 72.1,
72.3, 72.8, 74.9, and 75, with a mean of 73.2. Estimated planetary A
indices were 3, 3, 6, 9, 5, 6, and 23, with a mean of 7.9. Estimated
mid-latitude A indices were 2, 2, 3, 6, 5, 4, and 18, with a mean of


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