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ARRL Propagation Bulletin ARLP043 (2017)

ARLP043 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 43  ARLP043
From Tad Cook, K7RA
Seattle, WA  October 27, 2017
To all radio amateurs 

ARLP043 Propagation de K7RA

Solar activity increased over the past couple of weeks, with average
daily sunspot numbers at 13.4 on October 19-25, compared to 1.7 over
the previous seven days. Average daily solar flux increased from
70.5 to 76.7 over the same two weeks.

The reason for the radically different averages is because this past
week there were just two days with no sunspots, and the previous
week had no sunspot activity on six of the seven days. Thanks to Don
Wright, AA2F for noticing that the averages shown at the bottom of
last week's Propagation Forecast Bulletin ARLP042 were carried over
from the previous week's Propagation Bulletin, ARLP041.

Average daily planetary A index was 11.6, declining from 21.1 to
11.6, and average daily mid-latitude A index decreased from 16.7 to

Predicted solar flux for the near term is 78 on October 27, 77 on
October 28-30, 76 on October 31 through November 2, 77 on November
3, then 84 and 82 on November 4-5, 80 on November 6-17, 82 on
November 18-19, 84 on November 20, 85 on November 21-30, then 84 and
82 on December 1-2, and 80 on December 3-10.

Predicted planetary A index is 16, 12 and 8 on October 27-29, 5 on
October 30-31, then 8 and 16 on November 1-2, 15 on November 3, 5 on
November 4-6,  then 28, 30, 40, 28, 26 and 8 on November 7-12, 5 on
November 13-14, then 12, 10, 8, 6 and 5 on November 15-19, then 18,
45, 40, 18 and 12 on November 20-24, then 10, 8, 5, 8 and 10 on
November 25-29, then 5 on November 30 through December 3, then 28,
30, 40, 28, 26 and 8 on December 4-9, and 5 on November 10.

David Moore sent this:

F. K. Janda, OK1HH of the Czech Propagation Interested Group
presents his Geomagnetic activity forecast for the period October 27
to November 22, 2017.

Geomagnetic field will be:
Quiet on November 4, 6, 12-13
Mostly quiet on October 29-31, November 1, 3, 5, 15-17, 19
Quiet to unsettled on October 28, November 2, 18, 20
Quiet to active on October 27, November 7, 11, 14, 22
Active to disturbed on November 8-10, (21)

Amplifications of the solar wind from coronal holes are expected on
October (31), November (1-3,) 9-14, 20-21

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

Jeff, N8II of West Virginia on October 26 wrote:

"It has been a very interesting week on the bands with two major
European to East Coast 10M band openings and other days with 10M EU
QSOs here in eastern WV near DC.

"On Friday October 20, my first QSO on 15M SSB was LY3W in
Lithuania, a much farther north opening than usual. I then checked
12M CW and found 3B8DB, Mauritius at 1318z. After a brief break at
1338z, a run of western and southern Europeans answered my 12M SSB
CQs working as far east as Bulgaria.

"I then noticed a cluster spot of DM500RT in Germany on 10M CW who I
had just worked on 12M CW and SSB and he was good copy 559 and
logged him at 1355z.

"Italy and two French stations were logged over the next 15 minutes
followed by Brian, 9J2BO in Zambia all CW. At 1458z Henry, IZ5CML
was found S9 on 10M SSB and that was followed by a nice run of
Europeans on SSB.

"I logged Croatia, 3 Malta calls all from the same station (9H9GSM)
getting ready for the Boy Scout Jamboree, Portugal, Spain, Balearic
Island (EA6/DK5IR), and many Italians including two 5th area mobiles
(IW5EKR/M was S9).

"Last EU was Spain at 1536z. At 1518z S01WS, Western Sahara was
logged on 10 CW. 3C0L, Annobon Island, Africa operated by two very
talented Lithuanians was logged at 1804z on 10 CW. I then had a run
of very loud Brazilians on 10 SSB right after 3C0L. The SFI was
around 73, extremely low for a F2 10M opening to EU, the lowest I
can ever remember.

"The second noteworthy day was Tuesday October 24. At 1501z, YL2BJ,
Latvia was found on 12M CW, first northern EU of season. Then after
a break, I heard an OH8 station on 10M CW calling in a pile up on

"Moments later, I found OF6LW, Finland CQing with a S9 signal and
worked him at 1620z. I then was called by Finns OH3XR and OG2T,
OH0Z, Aland Island, and LA5LJA, Norway.

"Peter, SM2CEW called on 10 CW said he could see bright visible
aurora and the K index indeed rose to 4 here followed by as high as
6 later in the day.

"All of the Scandinavians had polar or auroral flutter, but only
LA5LJA was noticeably degraded copy with a buzz like note. I
experienced a similar opening in early March 2015 during the ARRL DX
contest, but the SFI was high enough that nearly all of EU was
workable. The opening was most likely auroral sporadic-E linked to
F2 on my end.

"Later at 1642z GI4DOH was found on 10 CW. I went on to log Spain,
Ceuta Africa (EA9ABC), Madeira Islands, Gibraltar, and last Canary
Islands at 1852z. SSB activity was high around 1800z with good
backscatter USA signals, but the EU opening did not favor my area.
None of the southern EU stations had any flutter."

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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 October 19 through 25, 2017 were 0, 0, 11, 13,
23, 23, and 24, with a mean of 13.4. 10.7 cm flux was 73.4, 75.7,
76.5, 77.3, 78, 77.5, and 78.8, with a mean of 76.7. Estimated
planetary A indices were 12, 8, 10, 6, 6, 18, and 21, with a mean of
11.6. Estimated mid-latitude A indices were 9, 5, 13, 6, 3, 13, and
15, with a mean of 9.1.


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