SB PROP @ ARL $ARLP001
ARLP001 Propagation de K7RA
ZCZC AP01
QST de W1AW
Propagation Forecast Bulletin 1 ARLP001
From Tad Cook, K7RA
Seattle, WA January 5, 2018
To all radio amateurs
SB PROP ARL ARLP001
ARLP001 Propagation de K7RA
No sunspots appeared from December 27, 2017 until January 4, 2018.
As Solar Cycle 24 declines to a minimum over the next two years we
should see longer and more numerous periods of no sunspots. On
January 4 the daily sunspot number was 13, indicating 3 sunspots in
one sunspot group, although Spaceweather.com reported no sunspots on
that day. The sunspot number for that day was reported by NOAA at
ftp://ftp.swpc.noaa.gov/pub/indices/DSD.txt .
On January 4 Spaceweather.com reported a stream of solar wind should
reach Earth on January 8, triggering some geomagnetic unrest, but
nothing severe.
Over the recent reporting week (Thursday through Wednesday) the
average daily sunspot number declined from 17.4 to 0, while
average daily solar flux went from 74.6 to 70.4.
Average daily planetary A index declined from 7.1 to 5.1, while
average daily mid-latitude A index went from 5.7 to 3.4.
Predicted solar flux is 70 on January 5-6, 69 on January 7-8, 68 on
January 9-11, 70 on January 12, 72 on January 13-24, 70 on January
25, 68 on January 26-31, 70 on February 1-8, and 72 on February
9-18.
Predicted planetary A index is 5 on January 5-6, then 8, 12 and 7 on
January 7-9, 5 on January 10-12, then 22, 16 and 6 on January 13-15,
5 on January 16-19, then 12, 10, 8 and 6 on January 20-23, 5 on
January 24-26, then 6, 25, 15 and 8 on January 27-30, 5 on January
31 through February 2, then 10, 12 and 6 on February 3-5, 5 on
February 6-8, then 22, 16 and 6 on February 9-11, 5 on February
12-15, then 12, 10 and 8 on February 16-18.
Geomagnetic activity forecast for the period January 5-January 31,
2018 from F.K. Janda, OK1HH:
"Geomagnetic field will be:
Quiet on January 5, 11, 17-19, 31
Mostly quiet on January 6, 10, 30
Quiet to unsettled on January 12, 15-16, 23-26
Quiet to active on January 7, 20, 22, 27-29
Active to disturbed on January 8-9, 13-14, 21
"Amplifications of the solar wind from coronal holes are expected on
January (6-8,) 10-12, (13,) 19-20, (21-22, 28-31).
"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 December 28, 2017 to January 3, 2018 were 0, 0,
0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 71.1, 71.5,
70.4, 70.7, 69.1, 69.5, and 70.7, with a mean of 70.4. Estimated
planetary A indices were 5, 4, 3, 4, 11, 5, and 4, with a mean of
5.1. Estimated mid-latitude A indices were 2, 3, 2, 2, 8, 4, and 3,
with a mean of 3.4.
NNNN
/EX
