Register Account

Login Help

ARRL Propagation Bulletin ARLP046 (2017)

ARLP046 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 46  ARLP046
From Tad Cook, K7RA
Seattle, WA  November 17, 2017
To all radio amateurs 

ARLP046 Propagation de K7RA

Thirteen days of zero sunspots ended on Tuesday, with sunspot numbers
of 14, 14, and 15 on Tuesday through Thursday.

In this week's bulletin average daily sunspot numbers increased from
0 to 4, while average daily solar flux decreased slightly from 70.8
to 70.3. Average planetary A index decreased from 15.6 to 12.3, and
average mid-latitude A index declined from 12.4 to 8.6.

Predicted solar flux is 74 on November 17-24, 75 on November 25-27,
then 73, 72 and 71 on November 28-30, 70 on December 1-2, 69 on
December 3-4, 68 on December 5-7, 69 on December 8-9, 70 on December
10, 73 on December 11-16, 75 on December 17-24, then 73, 72 and 71
on December 25-27, 70 on December 28-29, and 69 on December 30-31.

Predicted planetary A index is 14, 10 and 15 on November 17-19, 20
on November 20-21, then 18 and 10 on November 22-23, 5 on November
24-28, then 8 and 10 on November 29-30, 5 on December 1-3, then 35,
40, 28, 20 and 10 on December 4-8, 5 on December 9-10, then 15, 18,
12, 15, 12 and 8 on December 11-16, 20 on December 17-19, 8 on
December 20, 5 on December 21-25, 8 and 10 on December 26-27, 5 on
December 28-30 and on December 31 it jumps to 35, indicating
disturbed conditions.

Geomagnetic activity forecast for the period November 17 to December
13, 2017 from F.K. Janda, OK1HH of the Czech Propagation Interested
Group compiling this geomagnetic activity weekly forecast since

"Geomagnetic field will be:
Quiet on November 24-28, December 2, 9
Mostly quiet on November 19, 23, 29, December 8
Quiet to unsettled on November 18, December 1, 3, 11-12
Quiet to active on November 17, 30, December 4, 7, 12-13
Active to disturbed on November 20-22, December 5-6

"Amplifications of the solar wind from coronal holes are expected on
November (17-19,), 20-24, (29-30,) and on December (1-5,) 5-7, 9-12.

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

ARRL SSB Sweepstakes contest is this weekend. Rules can be found at .

Out of Japan, this study confirms that during sunspot cycle
minimums, solar activity is consistent from cycle to cycle, but not
at solar cycle peaks:

Bruce Smith, AC4G in Taft, Tennessee wrote on November 9:

"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 gray 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 Nov. 6 Nov 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.

"73, Bruce/AC4G/Taft, TN/EM65"

The earlier QSO that Bruce referred to was covered in the April 12,
2013 issue of Propagation Forecast Bulletin ARLP015.


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 9 through 15, 2017 were 0, 0, 0, 0, 0,
14, and 14, with a mean of 4. 10.7 cm flux was 65.8, 68.6, 67.3,
69.4, 72.1, 74.4, and 74.2, with a mean of 70.3. Estimated planetary
A indices were 20, 21, 8, 6, 6, 11, and 14, with a mean of 12.3.
Estimated mid-latitude A indices were 11, 13, 7, 4, 6, 8, and 11,
with a mean of 8.6.


Instragram     Facebook     Twitter     YouTube     LinkedIn