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ARRL Propagation Bulletin ARLP042 (2016)

ARLP042 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 42  ARLP042
From Tad Cook, K7RA
Seattle, WA  October 14, 2016
To all radio amateurs 

ARLP042 Propagation de K7RA

At 0356 UTC on October 13, the Australian Space Forecast Centre
issued this geomagnetic warning:

"Increased solar wind speed due to coronal hole effects expected for
14-15 Oct. Active conditions forecast with possible Minor Storm

14 Oct:  Active to Minor Storm
15 Oct:  Active"

Solar flux and sunspot numbers rose over the past week, while
geomagnetic indicators were down.

Average daily sunspot numbers for October 6-12 rose 34.3 points to
55, and average daily solar flux rose 15.2 points to 101.9,
referenced to the previous seven days.

Average planetary A index declined from 21.4 to 6.6, and
mid-latitude A index from 15.1 to 5.

Predicted solar flux is 95 on October 14, 90 on October 15-21, 85 on
October 22-26, 80 on October 27-29, 90 and 95 on October 30-31, 100
on November 1-2, 105 on November 3-7, 110 on November 8-9, 105 and
100 on November 10-11, 95 on November 12-14, 90 on November 15-17,
and 85 on November 18-22

Predicted planetary A index is 60 and 25 on October 14-15, 15 on
October 16-17, 10 on October 18-20, 5 on October 21-22, 20 on
October 23, 35 on October 24-26, 20 on October 27, 15 on October
28-30, 25 on October 31, 12 on November 1, 5 on November 2-6, 8 on
November 7-8, then 5, 12 and 15 on November 9-11, then 12, 20 and 8
on November 12-14, 5 on November 15-18, 20 on November 19 and 30 on
November 20-22.

Here is the weekly geomagnetic forecast from OK1HH.

"Geomagnetic activity forecast for the period October 14 - November
10, 2016

"Geomagnetic field will be:
Quiet on October 20, November 8-9,
Mostly quiet on October 19,
Quiet to unsettled on October 21, November 2-7
Quiet to active on October 14-(16), 18, 22, 26-28, November 10
Active to disturbed on October 17, 23-25, 29-30, November 1

"Amplifications of the solar wind from coronal holes are expected on
October 14-(16), 22-24, November 6-10

"Remark: - Parenthesis means lower probability of activity

Interesting article about interaction between various solar activity
from New Jersey Institute of Technology:

Jon Jones, N0JK wrote early this morning:

"A geomagnetic storm was in progress the evening of Oct. 13 (Oct. 14
UTC). During the storm sporadic-E appeared on 6 meters across the
desert southwest states.

"Here in Kansas -- KS7S DM41 was strong on 50.140 MHz at 0115z Oct
14. N0LL EM09 heard the XE2HWB DL44 beacon loud at same time.
Sporadic-E is rare in October, perhaps related to the geomagnetic

No doubt! The planetary A index yesterday (Thursday, October 13) was
43. Predicted planetary A index for today, October 14 is 60! More
excitement anticipated.

I had an email exchange over the past week with Bil Paul, KD6JUI of
Dixon, California about operating from his kayak, which is described
in his article "A Multi-band Antenna for Kayaks and Boats" in the
November 2016 issue of QST. Here is what Bil wrote.

"I saw the solar flux was predicted to be 99 yesterday (Oct. 6) so
went out in my kayak with the kayak antenna I devised (in Nov. QST)
and had some stateside QSOs (longest distance: Maine) -- but all
those were obtained by answered others' CQs. Then I called a CQ on
my own on 17m SSB running 10 watts and JH1OCC answered. He was
having no trouble copying me but with my very modest antenna I had
trouble copying him. I was sitting in saline river water on the edge
of the Sacramento River but between him and me was only land. So I
was quite surprised to snag him. There were other foreign stations
coming in on 17m but I never try to compete in pileups!"

By the way, even though the predicted solar flux for October 6 was
99, the actual value rose to 101.5 on that day, and the increase
continued over following days til it reached 104.5 on October 9.
Solar flux is expected to rise in a similar manner on November 1-11,
reaching a peak of 110 on November 8-9.

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 the
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 6 through 12 were 55, 50, 62, 58, 64,
56, and 40, with a mean of 55. 10.7 cm flux was 101.5, 104.2, 104.3,
104.5, 102, 99.2, and 97.6, with a mean of 101.9. Estimated
planetary A indices were 6, 6, 8, 5, 11, 4, and 6, with a mean of
6.6. Estimated mid-latitude A indices were 4, 5, 7, 4, 7, 3, and 5,
with a mean of 5.


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