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The K7RA Solar Update


Tad Cook, K7RA, Seattle, reports: Over the past week our sun has been quite active, with rising sunspot numbers and solar flux showing strong evidence that Solar Cycle 25 is progressing.

Average daily sunspot number rose from 12 last week to 27.9 in the current week, while solar flux rose to a high of 103.7, bringing average daily solar flux up from 79.8 to 90.1.

Average daily planetary A index rose from 3.1 to 9.9, and average daily middle latitude A index went from 2.1 to 7.7.

Predicted solar flux is 106, 108, and 105 on November 27 – 29, 102 on November 30 – December 4; 92, 88, and 85 on December 5 – 7; 82, 80, and 78 on December 8 – 10; 75 on December 11 – 17; 77, 80, 90, and 92 on December 18 – 21; 94 on December 22 – 25; 92 on December 26 – January 1, 88, 85, 82, 80, and 78 on January 2 – 6, and 75 on January 7 – 10.

The Planetary A Index forecast shows values of 8 on November 27; 5 on November 28 – December 17; 12, 24, and 18 on December 18 – 20; 10, 12, and 10 on December 21 – 23; 5 on December 24 – 29; 8 on December 30 – 31, and 5 on January 1 – 10.

Solar flux is measured three times a day in Penticton, British Columbia, Canada, and values have risen steadily in the past few days. Starting at 2200 UTC on November 24, they were 99.6, 102.8, 103.7, 104, 105.7, 105.8 and 110.2. The official daily flux value is taken at 2000 UTC (noon local time in Penticton). See the article, “The Solar Flux Radio Telescope at Penticton BC” by John White ,VA7JW.

Here’ the geomagnetic activity forecast for November 27 – December 22 from J. K. Janda, OK1HH. The geomagnetic field will be:

  • quiet on December 7, 12-14, (15-16)

  • quiet to unsettled on November 29-30, December 1-2, 6, 8, 11

  • quiet to active on November 27-28, December 3-5, 9-10, 17, 22

  • unsettled to active December 18, 21

  • active to disturbed December 19-20

  • solar wind will intensify on November (30,) December (2,) 3-5, (9,) 17-19

Note: Parentheses mean lower probability of activity enhancement. The predictability of change remains lower because of some ambiguous indications, and the situation is rapidly changing — an indicator of further growth in activity.

Jon Jones, N0JK, reported on November 25, that sporadic E was picking up on 6 meters as Thanksgiving approached:

K0GU (DN70) into northeast Kansas via Es on 50.313 MHz ~ 2344 UTC has –12 dB signals on FT8 on November 24.

K0GU made a number of contacts into the St. Louis and W9 areas. Also saw AC4TO (EM70) in Florida working Brazil ~ 0050 UTC on November 25. May have been a sporadic E link to TEP or possibly direct TEP. And this spot:

PY1MHZ        20/11/25          0057Z  50313.0 Into EM70    AC4TO

KA3JAW reported November 25, sporadic e, both double- and triple-hop rolled-up on 10 meters for 6 hours starting around 1253 UTC and continuing until 1921 UTC. Background noise level was 4 dBm on the meter. The following countries, states were heard: Trinidad, West Indies, Arizona, Colorado, Kansas, New Mexico, Oklahoma, Texas, and Washington, as well as Canada. Texas was the most-heard state. What was different with this event was the lack of southeastern states.

Bill Herzberg, AA8WH, of Dearborn Heights, Michigan, reported that 10 meters is alive and well.

“Starting after noon on November 25, I decided to check out the 6 and 10-meter FT8 frequencies. Wasn't much happening on 6, only heard a few calls, so I moved down to 10. Boy, what a difference; 10-meter FT8 signals were coming in from all over the place.

“I decided to go down to the sideband portion and see what was going on. Heard lots of SSB stations around 28.4. Heard some more above that.

“Went down to 28.3, and heard several really strong stations.

“Went down to the beacon subband, heard [a lot of] beacon stations, some doubling up on frequencies.

“So I went down to 12 meters. Heard several SSB stations, FT8 was hopping; 15 was wide open, as was 17, and 20 was also going strong.

“I think it was a combination of better conditions and a lot of folks [being] home for the holidays.

“Nice to hear the bands open. It's a taste of what's coming, when it will be possible to work the world with a few watts. Those times are coming, and it won't be soon enough for me.

Thanks to Paul, NO0T, for this recording of Scott McIntosh’s presentation to the Front Range 6 Meter Group concerning Solar Cycle 25. Some of what he reports is quite startling and optimistic.

Barring some disturbance, operators in this weekend’s CQ World Wide CW DX Contest could experience the best conditions in years. Coming up in 2 weeks is the ARRL 10 Meter Contest, which will especially benefit from higher solar activity.

See this article on helioseismology and sunspot prediction.

Space Weather Woman Tamitha Skov, WX6SWW, is very excited about the new solar activity.

Sunspot numbers for November 19 – 25 were 11, 11, 23, 35, 38, 37, and 40, with a mean of 27.9. The 10.7-centimeter flux was 76.7, 81.7, 85, 87.7, 95.5, 100.4, and 103.7, with a mean of 90.1. Estimated planetary A indices were 3, 8, 12, 27, 8, 4, and 7, with a mean of 9.9. Middle latitude A index was 2, 9, 9, 19, 7, 4, and 4, with a mean of 7.7.

For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…,” and check out K9LA’s Propagation Page.

A propagation bulletin archive is available. For customizable propagation charts, visit the VOACAP Online for Ham Radio website.

Instructions for starting or ending email distribution of ARRL bulletins are on the ARRL website.

Share your reports and observations.



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