[SFDXA] The K7RA Solar Update

[Bill]

    The K7RA Solar Update

01/20/2017

Last week’s bulletin featured zero sunspots for the entire seven 
days. This week (January 12-18) the average daily sunspot number rose to 
22.6.

Average daily solar flux rose from 72.5 to 77.1. Average planetary A 
index declined from 14.3 to 6.

Predicted solar flux is 80 on January 20-23, then 78, 77 and 75 on 
January 24-26, 77 on January 27 through February 1, 76 on February 2, 75 
on February 3-8, 76 on February 9, 77 on February 10—14, 78 on February 
15, 80 on February 16-21, 78 on January 22, and 77 on January 23-28.

Predicted planetary A index is 15, 12, 10 and 8 on January 20-23, 5 on 
January 24-26, then 12, 15, 7, 10, 12 on January 27-31, then 16, 18, 20, 
16, 12, 10 and 8 on February 1-7, and 5 on February 8-12, then 8, 22 and 
18 on February 13-15, 16 on February 16-18, then 12 and 8 on February 
19-20, then 5 on February 21-22 and 12, 15, 7 and 10 on February 23-26.

Geomagnetic activity forecast for the period January 20-February 15, 
2017 from F.K. Janda, OK1HH:

*Geomagnetic field will be:*

*Quiet on January 25-26, February 10, 13-14*

*Mostly quiet on January 24, 30, February 6, 9, 11-12*

*Quiet to unsettled on January 23, 27, 31, February 1, 3*

*Quiet to active on January 20-22, 28-29, February 7-8*

*Active to disturbed on January February 2, 4-5, 15*

*Amplifications of the solar wind from coronal holes are expected on 
January 20-21, (22-25,) 26, (31,) February (1-5,) 9, (15)*

*Remark:*

*- Parenthesis means lower probability of activity enhancement.*

*- Observed indicia of upcoming MAJOR CHANGES in solar activity!*

*Therefore, the current forecast is less reliable.*

Time now to examine the average daily sunspot number for 2016, which was 
36.8. Starting from solar cycle 24 minimum in 2008, annual average daily 
sunspot numbers were 4.7, 5.1, 25.5, 80.1, 82.3, 97.1, 121.2, 70.1 and 36.8.

The January 11, 2017 issue of /ARRL Contest Update/ (current and back 
issues available at*http://www.arrl.org/contest-update-issues*) mentions 
a new online propagation prediction program from G4FKH via RSGB. The 
link to /ITURHFprop/ is at *http://bit.ly/2jTVHFQ*.

The Atacama Large Millimeter/submillimeter Array (ALMA) telescope in 
Chile is providing new detailed images of the sun. See 
*http://bit.ly/2ka6JKh* for details.

More info from regular contributor David 
Moore:*https://www.sciencedaily.com/releases/2017/01/170117101835.htm*

John Kelley, K4WY, wrote on January 17: "Great timely info as always 
thank you! I wanted to share with you that on January 2 on 17 meters I 
worked E51DMC, VK2DX and ZL4FF all within a spread of an hour. I was in 
Virginia and running 100 watts to a loop and was really surprised when I 
checked the SN count and A and K indexes. Could not have been much 
worse! So, I am at a loss as to how to explain the propagation! But I 
liked it at least for that hour."

The sunspot number was zero on that date, and the day prior. There was 
one brief sunspot appearance the next day, then none at all from January 
4-11. But given those numbers and daily solar flux (around 72-73) there 
should be some pretty good propagation during that period. W6ELprop 
predicts for that date that ZL4FF might receive your 17 meter, 100-watt 
signal from 1530-1930z fairly reliably.

To VK2DX, the prediction shows good propagation 1800-2100z. To E51DMC, 
it looks good on 17 meters from 1700-2030z.

For more information concerning radio propagation, see the ARRL 
Technical Information Service 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 12 through 18, 2017 were 11, 24, 25, 23, 24, 
26, and 25, with a mean of 22.6. 10.7 cm flux was 75.5, 74.9, 76.6, 
77.5, 78.3, 78.6, and 78.6, with a mean of 77.1. Estimated planetary A 
indices were 5, 4, 4, 5, 3, 4, and 17, with a mean of 6. Estimated 
mid-latitude A indices were 3, 3, 3, 2, 2, 3, and 11, with a mean of 3.9.