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The K7RA Solar Update

12/25/2020

Tad Cook, K7RA, Seattle, reports: Merry Christmas!

Sunspots went missing last Friday and Saturday, but large new sunspot group 2794 appeared on Sunday, December 21, and on Wednesday, Spaceweather.com reported new sunspot group 2795 emerging over our sun’s southeastern limb.

This disappearance depressed the average weekly sunspot number, which went from 17.4 last week to 10.3 this week, ending on Wednesday, December 23. Our reporting week runs from Thursday through Wednesday.

In spite of lower sunspot numbers, the average daily solar flux increased slightly from 82.1 to 82.8.

Average daily planetary A index increased from 4.7 to 7.3, and average daily middle latitude A index went from 3.3 to 6. These are still low numbers, indicating quiet geomagnetic conditions, so 160-meter propagation remains good, also aided by lower seasonal atmospheric noise as winter begins in the Northern Hemisphere.

Predicted solar flux for the next 30 days is

88 on December 25 – 30; 86 on December 31; 84 on January 1 – 6; 82 on January 7 – 12; 84 on January 13 – 20, and 86 on January 21 – 23.

Predicted geomagnetic indicators for the same period have the planetary A index at 15 and 8 on December 25 – 26; 5 on December 27 – January 4; 10 on January 5 – 6; 5 on January 7 – 12; 8 on January 13; 5 on January 14 – 16; 12, 8, and 18 on January 17 – 19, and 15, 10, 8, and 3 on January 20 – 23.

Here’s the geomagnetic activity forecast for December 25 – January 19 from OK1HH. Geomagnetic field will be:

  • quiet on January 4, 12 – 14

  • quiet to unsettled on December 28 – 31, January 1 – 3, 15

  • quiet to active on December 25 – 27, January 6, 8, 10 – 11, 16

  • unsettled to active January 2, 5, 7, 9, 17, 19

  • active to disturbed January 18

  • Solar wind will intensify on December (25,) 27 (28 – 29), (January 1 – 3, 7 – 9, 18,) 19

Notes:

-Parentheses mean lower probability of activity enhancement.

-The predictability of changes is lower again, as there are ambiguous and changing indications.

I wish you a blessed Christmas, positive thinking, and negative tests! — F. K. Janda, OK1HH, Czech Propagation Interest Group, compiling these geomagnetic activity weekly forecasts since January 1978.

Steve, NN4X, reported working a VK and a ZL via 15-meter long path around 1915 UTC on December 23 using FT8. NN4X is in Florida, southeast of Orlando. His antenna (two stacked six-element Yagis) is highly directional, so he has no doubt this was long path. He was also heard at 3D2 and KH6. He writes, “I’ve been a ham since 1977, and this stuff never gets boring!”

Check out his impressive array of antennas listed on his QRZ.com profile. He sent a PSK reporter screenshot showing he was copied all over the world, except Asia.

Jeff, N8II, wrote on December 19.

“Today, we had two contests — the RAC and 9A CW (Croatia, everybody works everybody). 15 was a bit marginal into western Canada, but I worked MB, SK, AB, and BC plus several VE3s on backscatter. 15 meters was open to southern and central EU at the 1400 UTC 9A CW start, but with few loud signals. By 1500 UTC most activity disappeared. 20 meter signals were loud from both eastern and western Canada and Europe, with the band starting to close around 1615 UTC. My last EU QSOs were with Geoff, GM8OFQ, in the Orkney Islands (S-9 + 10dB) and Tom, G1IZQ, (S-9 with QSB) just after 1700 UTC.

“Signals from EU have been weaker and openings much shorter on 15 meters in general this past week due to the drop in solar activity. One day I had a QSO with a loud Norwegian who was S-9 around 1400 UTC, but in general most signals have been from southern EU. 

“Our sunsets are already later here by 3 minutes, but sunrises will get later until about December 31 due to the elliptical orbit of the Earth, so openings to the east will get later.”

Here’s the latest from Tamitha Skov, WX6SWW.

Sunspot numbers for December 17 – 23 were 12, 0, 0, 11, 11, 11, and 27, with a mean of 10.3. The 10.7-centimeter flux was 81.6, 80.5, 81.7, 83.8, 79.6, 85.8, and 86.4, with a mean of 82.8. Estimated planetary A indices were 2, 3, 5, 4, 12, 13, and 12, with a mean of 7.3. Middle latitude A index was 2, 2, 4, 4, 8, 11, and 11, with a mean of 6.

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.

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