Register Account

Login Help


The K7RA Solar Update


Sunspots finally returned on September 29, after over two weeks with none.

Average daily sunspot numbers increased from 0 to 9.6, and average daily solar flux increased from 67.9 to 68.4 over the past week, September 27 through October 3.

Average daily planetary A index declined from 10.9 to 7.7, while average mid-latitude A index changed from 7.9 to 6.1.

Predicted solar flux is 68 on October 5-18, 70 on October 19 through November 2, 68 on November 3-14, and 70 on November 15-18.

Predicted planetary A index is 5 on October 5-6, 20 on October 7-8, 12 on October 9-10, then 10, 8, 5, 12 and 8 on October 11-15, 5 on October 16-17, then 10, 25, 14, 8 and 12 on October 18-22, 8 on October 23-25, then 10, 6, 12, 8 and 5 on October 26-30, then 8 on October 31 through November 2, then 20, 35, 10, 18 and 15 on November 3-7, then 8, 5, 10, 8 and 5 on November 8-12, and 5, 10, 25, 15, 8 and 12 on November 13-18.


Geomagnetic activity forecast for the period October 05-31, 2018 from F.K Janda, OK1HH.

Geomagnetic field will be:

Quiet on October 15-16, 29-30

Quiet to unsettled on October 12, 14, 27, 31

Quiet to active on October 5, 10-11, 20, 22-26

Unsettled to active on October 6, 9, 17, 28

Active to disturbed on October 7-8, 13, 18-19, 21

Solar wind will intensify on October 7-9, 11-13, 18-20, (27-28)

Parenthesis means lower probability of activity enhancement.


From Australia's Space Weather Services:


Geomagnetic activity is expected to increase to active levels on UTC day 7 Oct and to minor storm levels on 8 Oct. There is a remote chance that for short periods the geomagnetic activity may even reach major storm levels during this interval.

The disturbance is due to the expected arrival of CIR (Corotating Interaction Regions) and HSS (High Speed Streams) associated with a large recurrent positive polarity north polar connected coronal hole. The aurora may be visible on the local nights of the 7 and 8 October from Tasmania, coastline of Victoria and Southwest coast of Western Australia.



07 Oct:  Active

08 Oct:  Minor Storm

09 Oct:  Active


Following the recent temporary shutdown of the solar observatory in Sunspot, New Mexico, the local newspaper in Alamogordo ran this article by local astronomer Alan Hale, explaining some solar physics:


Ted Leaf, K6HI, had a comment about the K9SQG 40-meter observations last week. "Forty meters may be dead for DX, but not for NVIS. We have a daily 40m net at 4pm local Hawaii time. Goes all over the islands, out to more than 200 miles. Lots of S9+ signals. For a very low antenna, tell me how well you get out for DX?"

NVIS is Near Vertical Incidence Skywave propagation. See .

K9SQG wrote on September 28: "Interestingly, I've been having nightly schedules on 40 meters between Dayton, Ohio and Wimberley Texas, a distance of about 1500 miles perhaps, and signals both ways are +20-30 over S9 for an hour or more at a time. This is in the 9:30 to 11 pm range, Eastern time. I’m going to try earlier in the evening too and see about that."


On September 28, Bil Paul, KD6JUI, wrote: "Here's your kayak guy, Tad. I was operating today from the boat on 17 and 20-meter CW. I was using a poor wire antenna but managed two contacts on 17 meters.

However, I was amazed to hear France (F6HKA) and Italy (I8QJU) coming in loud and clear on 20-meter CW. I was unable to get any contacts on 20 meters but was surprised to hear these guys coming in like locals at around 1 pm Pacific time.”


The November 2016 issue of QST features an article by KD6JUI describing his kayak operations.


Charles, KW6G, wrote: “The equinox effects are definitely significant. Wednesday night, September 26, I worked an all-time new one for me: ZD9CW on Tristan de Cunha Island. He was on 40 meters around 0700 UTC and I got him on CW on the third call! I was running my Icon IC-7600 transceiver driving an Avon 1010 amplifier to a ground-mounted Butternut HF9V vertical antenna. I have copied him last night as well.

“Longer propagation does have its advantages. However, after working 277 DXCC entities, finding new ones during this time of the solar cycle is pretty difficult.”


Regarding comments by NN4X last week about noctilucent clouds and e-skip, Jon Jones, N0JK, mentioned that he discussed this subject in the most recent World Above 50 MHz column in QST.


For more information concerning radio propagation, see the ARRL Technical Information Service at For an explanation of 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 September 27 through October 3, 2018 were 0, 0, 13, 14, 14, 14, and 12, with a mean of 9.6. 10.7 cm flux was 67.1, 69.1, 68.7, 68.3, 70.1, 67, and 68.4, with a mean of 68.4. Estimated planetary A indices were 7, 8, 10, 6, 9, 8, and 6, with a mean of 7.7. Estimated mid-latitude A indices were 6, 8, 9, 4, 6, 6, and 4, with a mean of 6.1.





Instragram     Facebook     Twitter     YouTube     LinkedIn