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The K7RA Solar Update


Australia’s Space Weather Services issued a geomagnetic warning at 0132 UTC on December 9. It said that due to solar wind from a coronal hole, expect increased geomagnetic activity on December 10.

Both average daily solar flux and average daily sunspot numbers were higher over the December 3-9 period than on the previous week.

Average daily sunspot numbers increased from 41.6 to 48 and average daily solar flux rose from 97.2 to 102.2.

Geomagnetic indicators rose at well, with planetary A index rising from 9.9 to 12.6 and mid-latitude A index from 6.6 to 11.1.

Predicted solar flux for the near term is 112 and 115 on December 11-12, 120 on December 13-15, then 115 on December 16-17, 105 on December 18, 100 on December 19-26, 98 on December 27, 95 on December 28-29, 98 on December 30, 100 on December 31 and 105 on January 1-2, 100 on January 3-4 and 105 on January 5-11.

Predicted planetary A index is 22, 16 and 12 on December 11-13, then 10, 6, 10 and 6 on December 13-15, then 10 and 8 on December 16-17, 5 on December 18-26, then 18, 15 and 10 on December 27-29, and 5 on December 30-31, then 15, 20, 18 and 10 on January 1-4, then 8, 12 and 10 on January 5-7, and 8 on January 8-11.

Today we have an updated geomagnetic forecast from Petr Kolman, OK1MGW, of the Czech Propagation Interest Group. OK1MGW and OK1HH have made these weekly forecasts since 1978, 37 years!

Petr expects quiet to active geomagnetic conditions on December 11, quiet to unsettled December 12, mostly quiet December 13, quiet to active December 14-15, quiet to unsettled December 16, quiet December 17-22, mostly quiet December 23, quiet to active December 24-25, quiet to unsettled December 26-27, active to disturbed December 28, quiet to unsettled December 29, mostly quiet December 30-31, quiet to active January 1-3, quiet to unsettled January 4, and quiet to active again on January 5-6.

He expects increases in solar wind on December 11, 14-15, 24-25 and January 1-3 and 5-6.

So far this year we have an average daily sunspot number of 71.2, and by December 31 that average will probably not deviate much, because the 71.2 figure is based on 94 percent of the data we will have by the end of the day on December 31.

The average daily sunspot numbers for the years 2008-2015 were 4.7, 5.1, 25.5, 80.1, 82.3, 97.1, 121.2 and 71.2, with the last figure being a preliminary value. Cycle 23 had a peak year in 2001 at 176.7. The two previous years (1999-2000) each had a yearly average of daily sunspot numbers above 170 (173 and 170.3). So the peak of the previous cycle had much higher sunspot numbers, plus the peak was sustained over several years.

We finally received a couple of reports from participants in the CQ World Wide CW DX Contest a couple of weeks back, from N8II and NK8Q.

First from Mark Schreiner, NK8Q, in State College, Pennsylvania reporting on December 4:

“I only operated for a few hours from mid-afternoon (2000 UTC) on Sunday until the end of the contest at 2400 UTC. 10m was open okay at that time and I put quite a few stations in the log, then moved to 15 meters to continue doing the same. It was open better than 10 meters and I mostly managed to work stations into South America on both bands, but also the farther reaches of North America as well. I finished off with 20 meters for the last 60-90 minutes with most of the contacts during that time into Japan. It is always fun having a run in the log to JA-land!

“I'm looking forward to the 160 meter contest this weekend (this was written on December 4, so the 160 meter contest was actually last weekend, December 5-6). I did a quick check of the antenna (an Inverted-V; I sure miss my Inverted-L from my previous home.) at the clubhouse of Nittany ARC just outside of State College, Pennsylvania last night to make sure it was still functional. Last year was the first year it was functional since I moved to this area about 5 years ago.

“I didn't have time to check the Beverage antenna we deployed last winter, but may do so on Saturday with some daylight to get its advantage into Europe on Saturday night. I have to work until 2200 UTC and then have dinner with my wife, but plan to spend most of the night at the clubhouse to operate for the evening and at least until 0800 UTC.

“Saturday night I can't get on until much later due to a surprise birthday party, but afterward I'll be on the air until at least 0800 UTC again. I'm hoping conditions are favorable for others to hear my QRP signal as I've done in the past!”

Uh-oh Mark. Now that this bulletin has been read all over the world, is that birthday party still a surprise? I guess so, since it actually happened last week.

Next, from about 94 miles directly south of NK8Q, we have a report from occasional contributor Jeff Hartley, N8II, in Shepherdstown, West Virginia:

“Here is a brief summary of CQWW CW from here.

“160 meters: It was not a good weekend for those short of the super station level. There seemed to be a lack of Caribbean signals as well as weak signals from Europe, but I did manage 9A (Croatia), OZ1IKY (the European leader, it appears, in Denmark), S5 (Slovenia), DL (Germany), OM (Slovak Republic), and EI (Ireland) the first night, but the second night was worse.

“80 meters: Conditions were okay, but European stations were not loud around 0300 UTC the first night, then quite good by 0430-0530 UTC including northern Europe and Russia. 4X (Israel) and TC0A in Turkey were logged. JA3YKC was heard, but weak around Saturday sunrise.

“40 meters: Plenty of European activity through the night until I had to QRT both days, Zone 14 weakened around 0300-0400 UTC the first night. It was surprising that Europe did not drop out around 0200-0400 UTC. Even the second night, European activity kept the band crowded with many S9+ signals. I worked 4X, A7 (Qatar0 and 7Z1 (Saudi Arabia) in the Middle East and 3D2 (Swaziland) and JA around Sunday sunrise. SU90IARU (Egypt) was my only Zone 34 contact of the contest. I did work all zones on all bands. Several multi-op stations claimed all zones on 40 and 20 Meters as did W3LPL on 15 Meters.

“20 Meters did not disappoint at the start with the band open to some degree in all directions; I made WAC including DP1POL in Antarctica in the first 17 minutes! AF (Africa) signals were loud, logging all AF zones except 34 and 39 by 0130 UTC. HS, JT, BV and BY were logged within the same 10 minutes. Signals were loud from Europe and Zone 17 (Asiatic Russia) around sunrise and again from 1800-2000 UTC. The northern European stations were loud from 2100 UTC right through 0100 UTC Saturday evening along with East and some central Asians. I logged 37 Zones total missing 30, 34, and 39.

“15 Meters; Worked almost a thousand European stations during my 24 hour total effort! Both days featured good openings to European Russia, but I never logged 17 just beyond the UA4 stations that called. Northern Europe was in Saturday afternoon until at least 22Z via probable auroral Es, and also on 20 Meters as noted. Saturday evening I worked YE1K (Indonesia), BY, DS4, 9M6NA and AH0K along with loud JAs.

“10 Meters: I made only 223 contacts vs 915 last year. The band opened to Europe both days, but almost entirely southern and western Europe, never hearing Zone 16. All of the African zones except 34 were present and loud around 1645Z Sunday working 5R, ZD8, C92, D4, and three ZS stations. The band never opened well to the northern Caribbean while I was active due to the declining solar flux. Time spent there was interesting, but the Pacific and JA were tough.

“Overall the low K index and solar flux around 100 provided very decent conditions except on 10 and 160 meters. The northern European stations were treated to a great weekend compared to averages in November.”

Don’t miss the ARRL 10 Meter Contest this weekend. Although solar activity isn’t high, this contest is scheduled to take advantage of ionization from meteor trails during the Geminids meteor shower.

This year the peak of the shower should be late in the contest.

Look here for details:

Note all the multipliers in Mexico you can work:

Check this for rules and details:

In the November 30 propagation bulletin, ARLP048, we mentioned Don, W9IXG and problems on 75 meters with his local/regional network. ( I suggested that solar activity is low enough that it may not always support regional communications on 75 meters. In other words, the ionosphere directly overhead is not energized enough to reflect signals back to stations below.

Ted Leaf, K6HI, of Kona, Hawaii suggests switching to 40 meters when 75 meters isn’t working. Ted wrote, “I am on our Army MARS net on 40, and it works well across all the islands. Our antenna heights on 40 are NVIS.” In other words, he uses antennas on 40 meters that are low enough to support Near Vertical Incidence Skywave propagation.

Note that via links at the bottom of the page you can navigate back to page 1, or out to page 8 and beyond for more information on NVIS antennas and propagation. W9IXG replied: “Thanks for the recommendation. We will investigate using 40 meters during radio blackout conditions on 75 meters. Our net runs from 1100-1315 UTC, so finding an open frequency for that length of time could be a problem and I'll need to poll our 100+ members to see how many have access to 40 meters.

“Our NWS weather net has been operating since 1964 on 75 meters and while we have seen short periods of time when we've had no propagation, we've never experienced several continuous months of poor-terrible conditions. That being said, conditions do seem to be improving as we move into the winter.”

David Moore wrote: “The Sun is supposed to be entering a quiet period, but it's still showing signs of its 11-year peak of activity it reached in early 2014.”

Always good for tips on aurora, David also sent this link concerning widespread observation of Aurora Borealis in both North America and Europe recently:

David also sent this:

Dennis Markel, N1IMW of Bedford, New Hampshire wrote: “As you predicted, the ARRL 160 Meter Contest enjoyed very quiet conditions both nights - noise was at S1 to S2 on my FT1000mp here in Bedford. Similar conditions existed for the CQ World Wide on 160 meters as well.”

For more information concerning radio propagation, see the ARRL Technical Information Service at For an explanation of the numbers used in this bulletin, see An archive of past propagation bulletins is at More good information and tutorials on propagation are at

My own archives of the NOAA/USAF daily 45 day forecast for solar flux and planetary A index are in downloadable spreadsheet format at and .

Click on “Download this file” to download the archive, and ignore the security warning about file format. Pop-up blockers may suppress the download.

Monthly propagation charts between four USA regions and twelve overseas locations are at

Instructions for starting or ending email distribution of ARRL bulletins are at

Sunspot numbers for December 3 through 9 were 47, 25, 41, 38, 50, 58, and 77, with a mean of 48. 10.7 cm flux was 94.5, 97.6, 100.5, 102.2, 100.7, 111.2, and 108.8, with a mean of 102.2. Estimated planetary A indices were 4, 5, 16, 24, 20, 11, and 8, with a mean of 9.9. Estimated mid-latitude A indices were 3, 4, 14, 26, 16, 9, and 6, with a mean of 6.6.




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