No sunspots appeared over this reporting week (January 16-22) and on January 22 Spaceeweather.com reported currently the consecutive period of spotless days is 11. But all recent sunspots have had Cycle 25 polarity.

Average daily solar flux reported in last week’s bulletin was 72.5, and this week it was 71.2.

Average daily planetary A index went from 5.6 to 4.1, and the middle latitude A index changed from 3.7 to 3.

Predicted solar flux is 71 on January 24-31, 72 on February 1-5, 71 on February 6-20, 72 on February 21 to March 3, 71 on March 4, and 70 on March 5-8.

Predicted planetary A index is 5 on January 24-31, 10 on February 1-5, 5 on February 6-27, 10 on February 28 to March 3, and 5 on March 4-8.

Geomagnetic activity forecast for the period January 24-February 19, 2020 from F.K. Janda, OK1HH.

Geomagnetic field will be
quiet on: January 29-30, February 6-9, 13-16
quiet to unsettled on: January 24-28, February 1, 4-5, 10-11, 18-19
quiet to active on: (January 31, February 2-3, 12, 17)
unsettled to active on: no days
active to disturbed: no days

Solar wind will intensify on: January 24, February 2 (-3,) 6-7,
12-13, 18-19

Parenthesis means lower probability of activity enhancement.
The predictability of changes is lower again.

David Moore sent this article, “"Scientists measure the evolving energy of a solar flare's explosive first minutes": https://www.sciencedaily.com/releases/2020/01/200117122105.htm

The latest video from WX6SWW: https://bit.ly/2RY4HLZ

On January 21, G4KSG told me that two days earlier using a dipole at 30 feet he heard both sides of a EA3/JA7 QSO at 0900 UTC on 20 meters, but he did not specify the mode.

From Jeff, N8II: “Weather is very warm here after 4 inches of wet snow and 3 cold days this week, currently about 52 degrees F at 9 PM; 66 degrees tomorrow!

“I took down a 40-meter quad loop antenna today that performed poorly compared to my 80-meter dipole fed with ladder line. It took a while to remove all of the wire wrapped with stiff heavy wire at the insulators to prevent slippage and untie tight knots. I will put up a 40-meter dipole with higher average height.

“In the past month my band-slot totals have increased considerably, about 1950 slots since January 2017 as I recall counting the same country on CW and SSB on the same band as two slots. Very few DXpeditions were active, but activity and low-band conditions were good over the Christmas season. A UK group at ZC4UW in the British bases on Cyprus was active with over 25,000 contacts, but good for only 1 slot as ZC4A was on the air another year."

When there are no sunspots, 160 meters seems to improve, probably because of lower associated geomagnetic activity. In fact, geomagnetic activity is recently nearly non-existent. This weekend is the CQ World-Wide 160-meter CW contest. See details at https://www.cq160.com/rules.htm

Note the low geo-activity toward the end of 2019:

ftp://ftp.swpc.noaa.gov/pub/indices/old_indices/2019Q4_DGD.txt

Compared to 2015:

ftp://ftp.swpc.noaa.gov/pub/indices/old_indices/2015_DGD.txt

Note October 29-30, 2003!

ftp://ftp.swpc.noaa.gov/pub/indices/old_indices/2003_DGD.txt

Check this bulletin from back then:

http://www.arrl.org/w1aw-bulletins-archive/ARLP044/2003

Be sure to check out the SSN/flux values for that week!


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 http://www.arrl.org/propagation and 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 16 through 22, 2020 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 71.8, 70.1, 71.3, 71.8, 71.2, 70.5, and 71.9, with a mean of 71.2. Estimated planetary A indices were 5, 3, 4, 3, 2, 6, and 6, with a mean of 4.1. Middle latitude A index was 4, 2, 3, 2, 2, 4, and 4, with a mean of 3.