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The K7RA Solar Update


Solar flux and sunspot numbers barely budged last week. Average daily sunspot numbers went from 75 in the previous seven days to 77.6 in the week ending October 28. Average daily solar flux went from 118.2 to 110.9.

Predicted solar flux is 110 on October 30, 105 on October 31 and November 1, 100 on November 2, 95 on November 3-4, 90 on November 5, 85 on November 6-8, 90 on November 9, 95 on November 10-11, then 100, 105 and 110 on November 12-14, 115 on November 15-16, then 120, 115 and 110 on November 17-19, and 105 on November 20-24. Flux values then drop to 85 on November 30 through December 5, and next rise above 100 a few days later.

Predicted planetary A index is 12 on October 30-31, 8 on November 1-2, 45 on November 3-4, then 20, 15 and 12 on November 5-7, then 20, 25, 20 and 10 on November 8-11, and 8, 12 and 20 on November 12-14, 5, 8 and 12 on November 15-17, then down to 5 on November 18-21.

Geomagnetic conditions remain unsettled, then on November 30 through December 2 planetary A index is predicted to rise to 50, 40, and 25, an echo of the high values on November 3-5. In fact, this activity would be from the same area of the sun a whole solar rotation later, which takes about 27-28 days.

Here is the geomagnetic outlook from Petr Kolman, OK1MGW, of the Czech Propagation Interest Group. He expects the geomagnetic field to be quiet to unsettled October 30, quiet to active October 31 through November 3, active to disturbed November 4-5, quiet to unsettled November 6, quiet to active November 7-9, quiet to unsettled November 10, quiet to active November 11-13, mostly quiet November 14, quiet November 15-16, mostly quiet November 17-24 and quiet to unsettled November 25.

Petr predicts increased solar wind on November 1-5 and 11-13.

Dave Bono, K6OAK of Fremont, California sent this space weather story:

Jon Jones, N0JK, of Lawrence, Kansas wrote, “Remarkably good conditions on 10 meters during the CQ WW SSB contest last weekend. The higher solar flux and generally quiet geomagnetic field helped northern paths. A CME impact on October 24 sparked no geomagnetic storming. noted ‘Solar wind speeds abruptly jumped to more than 500 km/s as the CME passed by. The shockwave rattled Earth's magnetic field and caused electrical currents to flow through the ground of Norway's Lofoten islands. However, that's about all that happened. A full-fledged geomagnetic storm did not erupt, and few auroras have been reported. Why was the CME so ineffective? Its internal magnetic field did not connect to Earth's magnetic field; the mismatch mitigated the CME's impact.’

“JAs were well over S-9 Saturday afternoon of the contest to eastern Kansas. Europeans were very loud Sunday morning. The opening Sunday morning extended deep into Europe and even Asia. I worked Cyprus (P33W) and Crete (SV9GPV) for new ones with just 5 watts while mobile on 10.”

Jeff Hartley, N8II, of Shepherdstown, Kentucky sent this report: “October 19 began a very noticeable increase in the HF MUF with not much happening on 12 and 10 meters before then. I worked G3KML running 2 watts on both 12 and 10 meters in and out of the noise that day, but many other signals were S9.

“Besides many German and Dutch stations on 10 meter phone on the October 20, I was called by RA1WP and R2DEV, both S9.

“The K index climbed to 3 at 1500Z on the October 21, but the UK was still booming in here on 10 meters from 1339-1413Z. The first good northern European opening on 10 meters occurred on October 23 with loud EW, SM, and OH stations logged,

“The CQWW phone conditions were surprisingly good considering the SFI being just above 100. I moved to 10 meters Saturday at 1220Z about 50 minutes past sunrise just as it was opening to Europe with 9A, OK, I, SP, and EA stations the first to come through. At 1250Z Germany was loud and I started to run EU stations. VU2PAI called at 1252Z with a S9 signal.

“Scandinavian signals were also loud at that time. The first 10 meter Russian was a RA1 at 1303Z, but I never managed to work many Russians on 10 the whole weekend despite some spotty loud signals. Six EA6 stations were logged on 10, by far the best activity from the Balearic Islands in a contest for me. Northern Europe was spotty with a gap from 1320-1346Z with none logged, but central and western Europe were loud.

“Stations all over Europe except for northern Scandinavia and just a couple of UK were logged between 1400-1500Z. Just after 1500Z northern Europe faded. In the afternoon signals to the south were generally quite good except for stations from Puerto Rico (closer) who were skipping over my area. On Sunday, 10 meters was spotty for a good part of early and mid-morning. At 1250Z, only a few very southern Europeans were workable, TK, A7, and HZ were logged. I was not able to run stations well until about 1520Z when there was a tremendous opening to northern Europe and Germany. By 1700Z, there were still many loud mainly southern Europeans, but I was not able to run many.

“I operated very sparingly on the low bands. Several have mentioned that 160 was poor which it certainly was around 0100Z Sunday. Seventy five meters was in pretty good shape to Europe Friday evening around 0200-0300Z, but about 1/3 of the stations I could hear, could not hear me.

“Forty meters had good propagation around 0130-0200Z too, but it was a sea of QRM. At 0000Z Sunday, 40 was not nearly as good to Europe and you could barely tell there was a contest on 75 meters at 0100Z, with very weak Europeans except for EA and also heard some good strength signals from zone 33 (EF8, CN).

“Twenty m meters featured some good propagation to Europe at the start to EI, LX, OK, I, LZ, UR, EA, and F as well as TF and OH8 and a few zone 18 Asiatic Russians. From AF, zone 33 was very loud and ZS and D4 were also logged. Skip went long early to the south with the northern 2/3 of zone 8 gone into the skip zone by around 0020Z. 20 was open to South America, but some signals were very fluttery and weaker than what they might have been another night. Whenever the band was open well to Europe, it was very crowded. Signals were pretty loud most of the day with the strongest European signals around sunrise and again from 1800-2000Z. Both afternoons VU2's were in at S9 in the 1800Z hour.

“Fifteen meters was extremely crowded when open to Europe. Sunday morning the band was open very well to all of Europe before 1145Z. A92 Bahrain and Kazakhstan answered my CQs with loud signals as well as northern Europe and Russians from zones 16 and 17. At 1900Z, the western European big guns were still loud. The northern Caribbean also was skipping over me more than expected, but skip was short at 1900Z Sunday allowing even VP9 to be logged. JAs were loud at 2000Z which is 0500 JST Sunday. Sunday seemed to be the better day on 15.”

Jim Smith, K3RTU, of Aston, Pennsylvania wrote on October 26:

“It has been quite a while since I last wrote you about my backpack QRP activities! This summer was so stinking hot that I didn't get out very much, especially during July and August, but with the cool down in September and October here in southeast Pennsylvania, I've been quite active. I've been out two to four times a week to my favorite state park. Last week the gods of propagation were pretty good to me, but today was spectacular!

“I managed to work 3DA0NJ in Swaziland southeast Africa with my Icom IC-703 running 10 watts SSB and Buddistick vertical antenna. I think I was the first one to answer his CQ at about 1939 UTC on 18.129 MHz. I only received a 2x2 signal report from Nico, but after a few tries he got all my info. Nico is a very patient man with darn good ears and a very big antenna to say the least. I follow your propagation predictions religiously and they have really been helpful as today's results prove. Now that the temperature is cooling down I hope that the propagation continues to warm up even though we are on the downside of the solar cycle!”

As you can see from this week’s reports, even with the solar cycle downturn, there is still lots of great propagation.

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 October 22 through 28 were 94, 91, 74, 63, 72, 78, and 71, with a mean of 77.6. 10.7 cm flux was 120.5, 114.9, 106.3, 106.4, 106.2, 110.1, and 112.2, with a mean of 110.9. Estimated planetary A indices were 6, 7, 11, 8, 3, 4, and 3, with a mean of 6. Estimated mid-latitude A indices were 4, 5, 10, 7, 2, 3, and 1, with a mean of 4.6.




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