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ARRL Propagation Bulletin ARLP004 (2018)

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 26, 2018
To all radio amateurs 

SB PROP ARL ARLP004
ARLP004 Propagation de K7RA

Low solar activity continued over the past reporting week (January
18-24) with zero sunspots visible after January 19. Average daily
sunspot number changed from 7 over the previous seven days to 3.3
this week. Average daily solar flux was down slightly from 70.7 to
70.

Geomagnetic indicators were also quiet.

Predicted solar flux is 70 on January 26 through February 16, 68 on
February 17, 69 on February 18-19, 68 on February 20-26, and 70 on
February 27 through March 11.

Predicted planetary A index is 8 on January 26-27, then 5, 8, 10 and
8 on January 28-31, 5 on February 1-3, 8 on February 4-5, 5 on
February 6-8, then 8, 12 and 8 on February 9-11, 5 on February
12-14, then 8, 12, 8, 10, 10 and 8 on February 15-20, 5 on February
21-23, 10 on February 24, 5 on February 25 through March 2, 8 on
March 3-4, 5 on March 5-7, then 8, 12, 8 and 5 on March 8-11.

The OK1HH Geomagnetic activity forecast for the period January 26 to
February 21, 2018.

"Geomagnetic field will be:
Quiet on January 31, February 3, 6-8, 13-14
Mostly quiet on February 2, 9, 15, 19
Quiet to unsettled on January 26-27, 30, February 1, 12
Quiet to active on January 28-29, February 4-5, 11, 16-18, 20
Active to disturbed on February 10, 21

"Amplifications of the solar wind from coronal holes are expected on
January 28-31, February 5-6, (7, 9,) 10-12, 16-18

"Remark:
- Parenthesis means lower probability of activity enhancement.
- Current forecasts are continuing to be less reliable.

"F. K. Janda, OK1HH Czech Propagation Interest Group Compiling this
geomagnetic activity weekly forecasts since 1978."

Here is a graph of mode usage during 2017 compiled by ClubLog.org:  

http://bit.ly/2DCPw2e

https://www.youtube.com/watch?v=VQ2CpsQUNEofeature=em-subsdigest

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 18-24, 2018 were 12, 11, 0, 0, 0, 0, and
0, with a mean of 3.3. 10.7 cm flux was 71.1, 70.8, 69.6, 68.3,
70.1, 70.5, and 69.9, with a mean of 70. Estimated planetary A
indices were 2, 8, 8, 10, 12, 4, and 9, with a mean of 7.6.
Estimated mid-latitude A indices were 1, 6, 5, 8, 8, 3, and 6, with
a mean of 5.3.
NNNN
/EX