Register Account

Login Help


The K7RA Solar Update


Solar activity is increasing, suggesting that perhaps now in Fall 2013 we are in the midst of a second peak in cycle 24. We hope it sustains.

Sunspot numbers this week ran up all the way to 228, a level not seen in the past decade since October 27 through November 1, 2003 when the daily sunspot numbers were 238, 230, 330, 293, 266 and 277. Prior to that, on January 11, 2003 the daily sunspot number was 238.

Average daily sunspot numbers increased over 35 points to 162 (when compared to the previous seven day period, October 10-16).

Average daily solar flux increased over 13 points to 139.6.

Geomagnetic indices indicate a quiet geomagnetic field.

Predicted solar flux this week is 165 on October 25-27, then 160, 155, 145, 135, 130, and 115 on October 28 through November 2, 120 on November 3-5, 125 on November 6-10, 130 on November 11, 135 on November 12-13, then 130, 120, 115 and 120 on November 14-17, and 115 on November 18-20. Based on recurrence due to solar rotation, in 45 days flux values are predicted at 130.

Predicted planetary A index is 16, 12, 8 and 20 on October 25-28, 8 on October 29-30, 5 on October 31 through November 9, then 12, 15, 10 and 8 on November 10-13, 5 on November 14-16, then 10 and 8 on November 17-18. After November 18 everything looks very quiet (A index of 5) until 44-45 days out, when the prediction shows A index values of 12 and 15 on December 7-8.

Those predictions come from the United States Air Force Space Weather Squadron, and are made available to the public via NOAA.


This set of pdf slides gives a hint at some of the tools they use:

As usual, OK1HH gives us his own predictions for geomagnetic activity. He sees quiet to active geomagnetic conditions on October 25, quiet to unsettled October 26, mostly quiet October 27, quiet to active October 28-29, mostly quiet October 30, quiet October 31 through November 3, mostly quiet November 4, quiet to active November 5, quiet to unsettled November 6, mostly quiet November 7, quiet to active November 8-12, quiet to unsettled November 13, quiet on November 14-19, and mostly quiet November 20. He does not expect any days with active to disturbed conditions.

Pete Markavage, WA2CWA, of Sayreville, New Jersey reports great conditions on 10 meters this week, but using AM and FM instead of CW or SSB. Pete wrote, “Ten meters has been hot all week. During the late morning hours of October 22 I worked about 25 stations, all on AM, in a number of Eastern and Western European countries. AM power was about 90 watts into a 4 element tri-bander. In the late afternoon I worked a Japanese station on 10 FM direct with a 40 watt rig. On October 24 around 6:45 PM EDT, finally worked my first Japanese station on 10 AM. Six meters has been dismal for openings here in the East, but 10 meter activity is making up for it.”

A week ago we got this from Jeff Hartley, N8II, in West Virginia, but not in time for last week’s bulletin: “10 meter and 12 meter propagation has been up and down with the degree of disturbed conditions, but almost every day the Middle East and Southern EU are booming in on ten here.

"I listened Wednesday October 16 until 1430Z and ten never opened well to Europe, but that evening about 75 minutes past sunset I was able to work a weak JA on 10 meter CW, heard one more and worked another on 12 meter CW around 2400Z when the band seemed to be closing rapidly. Jimmy BX5AA (Taiwan) was S7 on 15 phone about 0010Z and easily logged, so it seemed the K index lowered as the day progressed. A day or two before 10 was wide open to Scandinavia around 1300-1400Z as well as several southern UA3 area stations worked on CW. Paths to Africa have been open very late into the day with TN2NS (Congo) loud at 2130Z on 10 phone and even later on 12 CW.”

Chip Margelli, K7JA, wrote (also last week): “From what I was able to hear in a brief tune around ten meters this morning (October 18), it is widely open to Europe, the Middle East, and Africa. Nice signals were observed from OD5ZZ and OD5NJ, several 4X/4Z stations, SU8JOTA (Boy Scout Jamboree On The Air in Egypt!), and generally signals from all of Europe were excellent. F6KHM (0.5 W) and MM3FYA (5 W to an attic dipole) were nice copy this morning (October 18) around 1600 UTC.

"Last night, 18 October at 0158 UTC, I worked FK8CP on 50.110.6 MHz. Remi peaked about 579 and was in for at least a half hour. QSB was very heavy, almost like meteor scatter at times, but he also became steady, solid copy at times, too.

"It's nice to have some prop!

"I run 200 W to a 7-element LFA Yagi on 6 meters, and the same 200 W to a 7-element OP-DES Yagi on ten meters.”

Ganesh, VU2TS, sends us this message from Karnataka: “With the sunspot activity quite low, the band conditions these days are poor - even though we are supposed to be experiencing the Solar Max!

"However, I wish to share with you my pet theory about amateurs ionizing the ionosphere. This weekend is the CQ WW DX SSB contest, and with something like 30 to 40,000 stations on the air at the same time, and some 30 percent of them using a kW or more, all the bands open up for long haul DX!  (Remember HAARP?)

"Just listen to the bands this weekend and you will be surprised at the unusual band openings!”

That’s right Ganesh, in order to feed the ionosphere we have to call, not just listen. It is part of the magic of radio.

Further evidence of the magic of radio is the fact that I am writing Friday’s bulletin while using an airline Wi-Fi connection during a flight from Seattle to Washington, DC. Like all other basic in-flight amenities, such as snacks, it is quite expensive. Of course, back when snacks were free, I couldn’t get an Internet connection in the air.

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

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 17 through 23 were 166, 154, 149, 117, 179, 228, and 141, with a mean of 162. 10.7 cm flux was 136.1, 139.9, 132.7, 133.4, 135.8, 146.3, and 152.7, with a mean of 139.6. Estimated planetary A indices were 9, 3, 3, 3, 2, 5, and 4, with a mean of 4.1. Estimated mid-latitude A indices were 10, 3, 3, 3, 2, 3, and 3, with a mean of 3.9.



Instragram     Facebook     Twitter     YouTube     LinkedIn