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The K7RA Solar Update

06/25/2021

Tad Cook, K7RA, Seattle, reports: Average daily sunspot number was 14 this reporting week (June 17 – 23), essentially unchanged from last week’s 13.9. Average daily solar flux increased from 75.2 to 79.3.

Geomagnetic indicators were quieter. Average planetary A index declined from 9.6 to 5.3, and average middle latitude A index dropped from 9.7 to 6.1.

Predicted solar flux is 82 on June 25 – July 1; then 80 and 78 on July 2 – 3; 75 on July 4 – 7; 78 on July 8 – 11; 75 on July 12 – 16; 78 on July 17 – 22; 75 on July 23 – 25, and 78 on July 26 – 30.

Predicted planetary A index is 5 on June 25 – July 3; 12 on July 4; 5 on July 5 – 8; 8 on July 9 – 10; 5, 15, and 12 on July 11 – 13; 5 on July 14 – 20; 8 on July 21, and 5 on July 22 – 30.

Sunspot Group 2833 is about to rotate over our sun’s western horizon, but I see promising activity around and beyond the eastern horizon when viewing the STEREO mission images. Also check the Solar Monitor site to see this emerging activity.

Note that the 2300 UTC June 22 solar flux reading from the Dominion Astrophysical Observatory in Canada jumped way up to 104.5. The official solar flux for that day was the noon reading, 80.8 at 2000 UTC.

Here’s the geomagnetic activity forecast for June 25 – July 22 from J.K. Janda, OK1HH.

The geomagnetic field will be:

  • quiet on June 27 – 28, July 1, 11, 16 – 17,

  • quiet to unsettled on June 25 – 26, July 6, 10, 14 – 15, 18 – 22

  • quiet to active on June 29 – 30, July 2 – 3, 7, 9

  • unsettled to active July 4 – 5, (8,) 12 ( – 13)

  • active to disturbed nothing foreseen

  • Solar wind will intensify on June (29,) 30, July (2,) 3 – 5, (9,) 10 – 12, (13 – 15, 18 – 20)

Note: Parentheses mean lower probability of activity enhancement.

Steve Gregory, VK3OT, sent details of a remarkable 6 meter opening on June 23 from Ukraine to Australia. He posted an image on his QRZ.com page. Steve sent info on other openings from UB7K in Crimea, all reports were using FT8.

KA3JAW looks for sporadic-e propagation on the FM broadcast band:

“Kyle Whitley from Moses Lake, Washington [DN07hc], received audio with RDS on an over-the-air broadcast from Spirit FM, WBVM, 90.5, Tampa, Florida, via double-hop sporadic-e on June 17 at 0135 UTC (1835 PDT). That is 2,377 miles. He is the only Washington State FM-DXer that I am aware of who nailed Florida. During the event, he was hearing and locking onto RDS from multiple Kansas stations via single-hop Es.

The odd part is that he only heard that one station (WBVM) along that line-of-bearing toward Kansas, then dropping into Florida. He used a portable SPARC SHD-TX2. WBVM runs 100 kW with an antenna at 850 feet AGL. Check this YouTube video (at around 2:40).

The US Postal Service has new postage stamps with solar images.

Here’s the latest video from Tamitha Skov, WX6SWW, the Space Weather Woman.

Sunspot numbers for June 17 – 23 were 12, 24, 15, 13, 11, 12, and 11, with a mean of 14. The 10.7-centimeter flux was 85, 77, 77.1, 76.4, 79.1, 80.8, and 79.7, with a mean of 79.3. Estimated planetary A indices were 7, 7, 4, 4, 4, 7, and 4, with a mean of 5.3. Middle latitude A index was 9, 8, 5, 4, 3, 8, and 6, with a mean of 6.1.

For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…,” and check out this 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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