Over the past week (August 25-31) average daily sunspot numbers rose from 33.9 to 60.1, and average daily solar flux increased from 79.6 to 87.9, compared to the previous seven days.
In fact, the average daily sunspot number for August was 50.4, the highest since February, when it was 56.1.
The three month moving averages of sunspot numbers for this year were 49, 45.3, 43.1, 35.4, 33 and 33.5.
Over the same period average planetary A index declined from 9.7 to 8, and mid-latitude A index went from 8.7 to 6.9. That’s a nice combination, lower geomagnetic activity and higher solar activity. As solar activity declines overall, there will be brief respites when sunspots increase, but only temporarily,
Predicted solar flux is 100 on September 2-4, 95 on September 5-8, 85, 78 and 80 on September 9-11, 82 on September 12-16, 80 on September 17-21, 82 on September 22, 85 on September 23-25, 82 on September 26-27, 85 on September 28-29, 80 on September 30 and October 1, 78 on October 2-7, 80 on October 8, and 82 on October 9-13.
Predicted planetary A index is 15 on September 2, 12 on September 3-4, 15 on September 5-6, 10 on September 7-8, 5 on September 9-12, then 10 and 8 on September 13-14, 5 on September 15-16, then 8, 5, 15, 12 and 8 on September 17-21, 5 on September 22-24, then 20, 18, 10, 15, 12, 10 and 8 on September 25 through October 1, 15 on October 2-3, 8 and 10 on October 4-5, and 5 on October 6-9.
Here are a couple of geomagnetic predictions from the Czech Republic:
Geomagnetic activity forecast for the period September 2-September 8, 2016
Quiet: Sep 6-8
Unsettled: Sep 2-8
Active: possible Sep 5-6
Minor storm: 0
Major storm: 0
Severe storm: 0
Geomagnetic activity summary:
After the observed active periods, we expect partial decrease to unsettled conditions. We expect the unsettled conditions at most for the whole forecast period. Between Sep 6 and 8, decrease to quiet conditions is possible.
Active periods can occur in the first half of forecast week; we expect only isolated events.
Institute of Geophysics of the ASCR, Prague
Department of Geomagnetism
Budkov observatory (BDV)
This is from last week’s bulletin. We did not receive their current forecast, so included a more recent short-term forecast above:
Geomagnetic activity forecast for the period September 1-21, 2016
Geomagnetic field will be:
Mostly quiet on September 9-11, 14-16, 18
Quiet to unsettled on September 1-3, 6-8, 12, 17
Quiet to active on September 4-5, 13, 19-21
Increased solar wind from coronal holes are expected on September 4-5, 12-13, 17, 19-21.
This e-mail from Jeff Hartley in West Virginia was dated August 26, but did not arrive in time to include in last week’s bulletin:
“I have been on the air a lot this week. There was a very long-lasting Es opening to St Paul Island, CY9C on Aug 24; I worked them on 15 SSB, 12, 10, and 6 meters, each on CW and SSB! Their 10 meter SSB operator said they made over 1000 6-meter contacts that day by around 1800Z and the opening lasted on 10 meter until just past 220Z! Ten meters was open to them probably all of the time except a few minutes from 1745-2200Z. It must have started fairly early in the AM and they had a very fast operator on 6 meters. I will send more detailed report if time this week. There were quite a lot of Es before the 24th, but nil the past 2 days.
“The skip zones on 20 and 40 were very long all day today, making it difficult to work National Parks on the Air east of WI, but Europe was loud in mid-afternoon until past 2230Z.”
Jeff sent another e-mail yesterday, September 1:
“When CY9C on St Paul Island just north of Nova Scotia started operating, it was easy to work them on all bands 20 meters and lower – including 160 meters. But I had to work them on backscatter on 17-meter phone, although it was surprisingly easy. They were quite weak on 15-meter CW backscatter one afternoon, but they heard me after a few minutes of calling while they were working southerly W4s who were loud here on a sporadic E opening. We had quite a bit of sporadic E as high as 10 meters into mostly FL. I also heard from the Gulf Coast states around to TX and up to OK on the 23rd, but nil to anywhere north. Then some Es magic occurred to CY9C on the 24th that made many operators happy on many high bands. I turned on the radio at 1756Z and found them loud (worked first call on 10-meter phone), then 2 minutes later on 12-meter phone. I listened back on 10 meters and the CY9C operator mentioned they had worked over 1000 contacts on 6 meters that day! They must have had several wide open Es for hours already by then.
“My 6-meter antenna is intermittently shorted, so I gave it a try with my small Force 12 10-15-20 meter tribander, which had a low SWR on 6 and I worked them right away on 50130 kHz CW, with their signals peaking around S5-7. I checked back once more around 1900Z and they were still coming through on 6 meters. I filled in the remaining slots on 15 phone (first call running 5W), 12-meter CW, 17-meter CW and then 10-meter CW at 2020Z with a booming S9 +15-20 dB signal. The Es opening apparently lasted until just past 2200Z. The operators were excellent and worked the high bands as much as they could that day.
“Since then, sporadic E has been almost nonexistent except for some on Saturday evening. The DXmaps.com Es MUF tool confirmed my observations. It estimates Es MUF for each grid square using cluster spots and several ionospheric sounders operated by the US government, the nearest to me being in southeast Virginia at Wallops Island.
“The 25th was the 100th anniversary of the National Park Service, so I spent the day trying to work National Parks on the Air stations who were very active through about 1900Z. It was a challenge with very long skip zones on 20 meters, and even on 40 meters, with a low solar flux. Even so, I worked almost all of them (several on backscatter) except for three in the northeast and Ohio. The next day, activity was still high with conditions a bit worse and my backscatter QSO luck ran out with many in the east completely in the noise and no Es again.
“Saturday started with making a few contacts in the Romanian DX contest, finding 15 meters open to all over Europe as far as RK4FD in southeast Europe, and Russia, Sweden and Lithuania as well. Most signals were S7 or weaker with many fading in and out of my low noise floor.
“Then, I worked the Kansas QSO Party, finding 20 meters to be nearly perfect for the whole operating period from 1400Z-0200Z Saturday and 1400Z-1900Z Sunday. I worked 475 Kansas contacts, mostly on 20 meters with about 90 on 40 meters. One hundred and four of the 105 counties were active. Forty meters was weak to Kansas in the afternoon until about 2200Z, but I caught some mobiles here and there. Virtually everyone was very good copy on 20 meters and the home stations with Yagis antennas were as loud as 30 dB over S9 and stations using wire antennas were over S9 at times. I think some Es saved 20 meters from closing to Kansas around 2400Z as stations in Ohio appeared on 40 meters who were working the Ohio QSO Party.
“Fifteen meters sounded dead Saturday afternoon except to Brazil, even though the Hawaii QSO Party was also taking place. I did work about 14 Hawaiian stations while also working Kansas on 20 meters including a few who called me. Signals were not really loud from there until 0100Z, but quite workable all day from 1730Z onward. Finally, on Sunday, 15 meters opened well to Hawaii, which I first noticed at 2000Z. I heard KH6TU working Spain. All of the stations were very easy to work, the loudest around S 7-9. I think the SFI was slightly higher. Also of note were loud European stations that were heard until around 2400Z Saturday off the back corner of my Yagi on 20 meters.”
The autumnal equinox is less than 3 weeks away. This always means HF conditions are likely to be better.
This story about a daylight star party in New Jersey mentions K2BOG, but not by call sign: http://bit.ly/2cilkwo
For more information concerning radio propagation, see the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals. For an explanation of the 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 August 25 through 31 were 39, 44, 52, 64, 67, 64, and 91, with a mean of 60.1. 10.7 cm flux was 78.7, 81.9, 83.9, 85.4, 87.8, 100.4, and 97.5, with a mean of 87.9. Estimated planetary A indices were 11, 7, 5, 3, 6, 16, and 8, with a mean of 8. Estimated mid-latitude A indices were 9, 5, 5, 4, 5, 12, and 8, with a mean of 6.9.