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ARRL Propagation Bulletin ARLP032 (2017)

ARLP032 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 32  ARLP032
From Tad Cook, K7RA
Seattle, WA  August 15, 2017
To all radio amateurs 

ARLP032 Propagation de K7RA

Sorry for the long delay in getting this bulletin out, which
normally occurs on Friday, but is now being released on the
following Tuesday. This was the result of an automatic operating
system update gone bad, which has me now actively considering open
source alternatives. It still isn't fixed.

Average daily sunspot numbers for the recent reporting week (August
3-9) rose 7.1 points to 12.1, and average daily solar flux rose from
71 to 73.2.

Average daily planetary A index went from 5 to 11.3, and mid
latitude A index rose from 6 to 10.9.

Predicted solar flux for the near term is 74 on August 15-21, 72 on
August 22, 68 on August 23-28, 70 on August 29, and 72 on August 30
through September 8.

Predicted planetary A index is 5, 16, 26 and 20 on August 15-18,
then 16, 14, 12, 10 and 6 on August 19-23, 5 on August 24-29, then
12, 24, 18 and 14 on August 30 through September 2, and 5 on
September 3-8.

W7WKR sent this:

Max White sent this:

Ward Silver, N0AX and others reminded me that the upcoming HamSCI
experiment this month in conjunction with the solar eclipse is not
actually sponsored by the ARRL, but is a creation of HamSCI, Ham
Radio Science Investigation. Check them out at, .

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 August 3 to 9, 2017 were 13, 13, 13, 13, 11, 11,
and 11, with a mean of 5. 10.7 cm flux was 75.1, 74.1, 74.1, 73.5,
72.7, 71.1, and 71.5, with a mean of 71. Estimated planetary A
indices were 12, 23, 16, 13, 5, 5, and 5, with a mean of 5.
Estimated mid-latitude A indices were 11, 19, 17, 13, 6, 5, and 5,
with a mean of 6.


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