SB PROP @ ARL $ARLP004
ARLP004 Propagation de K7RA

ZCZC AP04
QST de W1AW  
Propagation Forecast Bulletin 4  ARLP004
From Tad Cook, K7RA
Seattle, WA  January 27, 2017
To all radio amateurs 

SB PROP ARL ARLP004
ARLP004 Propagation de K7RA

Average daily sunspot number rose from 22.6 to 52.7 (from 0 two
weeks ago) and solar flux from 77.1 to 83.9, for the January 19-25
reporting week.

In addition to this recent uptick, the first sunspot group of Cycle
25 (12620) appeared on December 18. Carl Luetzelschwab, K9LA has an
excellent article about this in the next (February) issue of the
Northwest Indiana DX Club newsletter (see
http://nwidxclub.weebly.com/newsletters in early February).

Heliospheric Physicist Dr. Tamitha Skov mentioned the new Solar
Cycle 25 spot in a recent video:

https://www.youtube.com/watch?v=RMEJEwlm4gw

Sunspot 12620 was expected to return (if still active) around
January 4-6, but did not show again.

It appeared in these alerts on December 21-24:

http://bit.ly/2jZ04Q0

Here is an image from December 22:

http://bit.ly/2kt1UbM

Predicted solar flux is 82 on January 27, 80 on January 28, 78 on
January 29 through February 3, 75 on February 4-7, 76 on February 8,
77 on February 9-12, then 78, 79, and 81 on February 13-15, 83 on
February 16-18, then 85, 83 and 82 on February 19-21, 80 on February
22-24, 78 on February 25, 77 on February 26-27, 76 on February 29
through March 1, 75 on March 2-6, and 76 on March 7.

Predicted planetary A index is 15 on January 27-28, 8 on January 29,
12 on January 30-31, then 18, 15, 20 and 16 on February 1-4, 12, 10
and 8 on February 5-7, 5 on February 8-13, 15 on February 14, 10 on
February 15-16, 8 on February 17-19, 5 on February 20-22, then 12,
15, 8, 10, 12 and 16 on February 23-28, and 18, 20, 16 and 12 on
March 1-4.

F.K Janda, OK1HH sent us this:

"Geomagnetic activity forecast for the period January 27-February
22, 2017

"Geomagnetic field will be:
Quiet on January 27, February 1, 11-12, 14, 22
Mostly quiet on January 30, February 9-10, 20-21
Quiet to unsettled on January 31, February 13, 19
Quiet to active on January 28-29, February 3-5, 15, 17
Active to disturbed on February 2, 6-7 (8, 16, 18)

"Amplifications of the solar wind from coronal holes are expected on
January 26, (31,) February (1-5,) 9, (15)

"Remark: - Parenthesis means lower probability of activity
enhancement."

If you would like to make a comment or have a tip for our readers,
email the author at k7ra@arrl.net.

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at,
http://arrl.org/propagation-of-rf-signals. For an explanation of
numbers used in this bulletin, see
http://arrl.org/the-sun-the-earth-the-ionosphere.

An archive of past propagation bulletins is at
http://arrl.org/w1aw-bulletins-archive-propagation. More good
information and tutorials on propagation are at http://k9la.us/.

Monthly propagation charts between four USA regions and twelve
overseas locations are at http://arrl.org/propagation.  Instructions
for starting or ending email distribution of ARRL bulletins are at
http://arrl.org/bulletins.

Sunspot numbers for January 19 through 25, 2017 were 26, 61, 67, 61,
53, 55, and 46, with a mean of 52.7. 10.7 cm flux was 79.5, 83.2,
86.1, 86.8, 84.1, 82.3, and 85.1, with a mean of 83.9. Estimated
planetary A indices were 11, 11, 11, 9, 5, 3, and 6, with a mean of
8. Estimated mid-latitude A indices were 10, 9, 9, 8, 2, 3, and 4,
with a mean of 6.4.
NNNN
/EX