Register Account

Login Help

ARRL Propagation Bulletin ARLP045 (2017)

ARLP045 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 45  ARLP045
From Tad Cook, K7RA
Seattle, WA  November 10, 2017
To all radio amateurs 

ARLP045 Propagation de K7RA

No sunspots are visible so far in November, and as of November 9 we
have seen nine days of blank Sun. But the past few days had strong
geomagnetic activity, with planetary A index on November 7-9 at 36,
47 and 20, and so far on early November 10, at 21. 28 is the
predicted planetary A index for November 10.

According to, 24% of 2017 so far (76 days) have
seen 0 sunspots. In all of 2016 there were only 32 days (9%) with no
sunspots. There were no periods in 2015 with any visible sunspot

Average daily sunspot number dropped from 17.7 last week to 0 this
week, November 2-8. Average daily solar flux declined from 75.4 to
70.8. Average daily planetary A index changed from 6.4 to 15.6, and
average mid-latitude A index rose from 4.7 to 12.4.

Predicted solar flux is 66 on November 10-11, 68 on November 12-13,
70 on November 14-17, 75 on November 18-30, 72 on December 1, 71 on
December 2-3, 70 on December 4-10, then 71, 72, 73, 73 and 74 on
December 11-15, and 75 on December 16-24.

Predicted planetary A index is 28, 24, 12, and 8 on November 10-13,
then 5, 16, 12 and 10 on November 14-17, 5 on November 18-19, 20 on
November 20-22, 5 on November 23-28, 10 on November 29-30, 5 on
December 1-2, 10 and 27 on December 3-4, 30 on December 5-6, then
28, 25 and 10 on December 7-9, 5 on December 10-11, 10 on December
12-14, 5 on December 15-16, 20 on December 17-19, and 5 on December

Geomagnetic activity forecast for the period November 10 to December
6, 2017 from F.K. Janda, OK1HH of the Czech Propagation Interest
Group, who has been compiling this geomagnetic activity weekly
forecast since 1978.

"Geomagnetic field will be:

"Quiet on November 13-14, 19, 24-28, December 2-3
Mostly quiet on November 18, December 1
Quiet to unsettled on November 16, 20, 23, 29
Quiet to active on November 12, 15, 17, 30, December 30, December 4, 6
Active to disturbed on November 10-11, 21-22, December 5

"Amplifications of the solar wind from coronal holes are expected on
November 11-15, (16-19,), 20-24, (29-30,) and on December (1-5,)

- Parenthesis means lower probability of activity enhancement.
- Current forecasts remain less reliable."

Also we got this from Tomas Bayer of the Department of Geomagnetism
at Budkov observatory, also in the Czech Republic.

"Geomagnetic activity summary:

"At the Budkov observatory, we observed a minor storm event on
November 7, peaking at 1842 UTC. After this event, the conditions
are between unsettled to active and through November 10 we expect
the same level. Further, we expect at most unsettled conditions till
Sunday, November 12, and also probable unsettled event at the end of
the forecast period, Thursday, November 16.

"Between Monday, November 13, and Tuesday, November 15, we expect at
most quiet conditions only with minor unsettled event."

Hisako Koyama appears in the news again this week. Check out "Ms.
Hisako Koyama: From Amateur Astronomer to Long-Term Solar Observer"
at, .

Check out this article about an unusual solar event:

Bruce Smith, AC4G of Taft, Tennessee wrote:

"In April 2013, I was so excited to hear and make a QSO with VK9CZ,
Cocos-Keeling on 80m CW as reported in the ARRL Propagation Report.
The VK9CZ signal appeared all of a sudden out of nowhere with 579
signals at my sunset 2343z via long path. Other stateside operators
made the QSO including N4II who studied the technical aspects
(science) and wrote a few articles on the path of the VK9CZ signal
at grey line for April 2013.

"Recently, in Nov 2017, 4 years and 7 months later, VK9CZ put on
another DXpedition to Cocos-Keeling. To my surprise, I heard their
signals once again pop out of nowhere on 80 CW at my sunset (from
2235z until 2325z) early-November renewing my excitement. The
signals long path (SE Beverage antenna) were surpassing 599. I could
not pass another chance to say hello this year by giving the op on
that side a 599 signal report. His sigs peaked via long path at 10
dB over S9 at my Taft, TN QTH this year Nov 2017. Perhaps Fall long
path sigs are better than April sigs? There were several stateside
hams who made the 1 Nov logs on 80m. The online log only showed
about 36 QSOs in NA who had made the logs according to the Clublog
statistics that I was monitoring on 1 Nov.

"On 5 Nov, I could barely hear the VK9CZ signals long path via SE
Beverage antenna. Since then, a few other lucky operators logged an
80m QSO via LP with VK9CZ for a total of 71 80m QSOs as late as 6

"November 6 was one of their last operating periods closing out
their operation with another long path opening. The VK9CZ signals
peaked via LP about 539 on this day in Taft, TN. All other days not
described above, there were no apparent signals being received at my
location in southern Tennessee on 80m.

"My observations revealed one great long path opening at my sunset
and one mediocre opening, while the other long path openings were
nil to barely readable. As it was in 2013, both VK9CZ and my QTH
were in sunlight for both QSOs taking advantage of another sunrise

"I also monitored 160m on days no sigs were heard on 80m, but not a
whisper from the VK9CZ 160m signals at my sunset on many days
monitored or when 160m cluster spots indicated VK9CZ operations on

"By the time the readers read this, the DXpedition will have ended.
Hopefully, the next few years may bring other surprises on 80m/160m
for us all renewing the DX Spirit for all low band operators."

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 November 2 through 8, 2017 were 0, 0, 0, 0, 0,
0, and 0, with a mean of 0. 10.7 cm flux was 73.6, 73.2, 72.1, 71.1,
69.4, 68.3, and 67.6, with a mean of 70.8. Estimated planetary A
indices were 8, 9, 4, 3, 2, 36, and 47, with a mean of 15.6.
Estimated mid-latitude A indices were 12, 7, 2, 1, 0, 26, and 39,
with a mean of 12.4.


Instragram     Facebook     Twitter     YouTube     LinkedIn