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The K7RA Solar Update

05/18/2019

Tad Cook, K7RA, in Seattle, reports: Sunspot activity continues, and this reporting week, the average daily sunspot number rose from 16.1 to 22.7, while average daily solar flux went from 73.5 to 75.7. The two sunspot groups that appeared on May 3 and May 6 are fading fast and rotating off the visible solar disc. Two geomagnetically active days occurred on May 11 and 14, when the planetary A index reached 25 and 36.

Predicted solar flux is 72 on May 16 – 18; 70 on May 19; 68 on May 20 – 22; 67 on May 23 – 29; 70, 72, 74, and 76 on May 30 – June 2; 77 on June 3 – 11; 75 on June 12; 72 on June 13 – 14; 70 on June 15; 69 on June 16 – 17; 68 on June 18; 67 on June 19 – 25, and 70, 72, 74, and 76 on June 26 – 29.

Predicted planetary A index is 28, 20, and 8 on May 16 – 18; 5 on May 19 – 27; 10, 12, 8, and 10 on May 28 – 31; 5 on June 1 – 15; 8 on June 16; 5 on June 17 – 23; 10, 12, 8, and 10 on June 24 – 27, and 5 on June 28 – 29.

On May 10 Jeff, N8II in West Virginia reported a sporadic E opening on 10 meters.

“Even a couple of QRP stations with small antenna were loud. Starting around 1600 – 1900 UTC, I worked a mobile in South Carolina, several in north Florida, Louisiana, a couple of Tennessee, heard/worked all over Texas from Houston to Oklahoma border to west Texas, Missouri, several Illinois, several Indiana, Wisconsin, two Iowa, Nebraska,” he said.

“I also worked W2SDR in Salem County, New Jersey, apparently on Es backscatter; when I turned antenna from west to New Jersey, his signal did not improve (it was slightly weaker). All were 10 – meter SSB, most were S – 9 or better.”

Also on May 10, Jon, N0JK, reported 6 – meter sporadic E openings from Kansas.

“Here in the Midwest, the band was open to W1, W2, W3, and W4. It was probably the most widespread opening so far this season,” he reported. “I worked AA2UK FM29 at 1908 UTC on 6 meters. Saw PV8DX Brazil spotted to W1, W3, and W4.”

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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. Monthly charts offer propagation projections between the US and a dozen DX locations.

Sunspot numbers for May 9 – 15 were 25, 24, 26, 24, 23, 24, and 13, with a mean of 22.7. The 10.7-centimeter flux was 76.2, 76.3, 78, 76, 74.7, 74.4, and 74, with a mean of 75.7. Estimated planetary A indices were 7, 7, 25, 4, 6, 36, and 6, with a mean of 13. Middle latitude A index was 8, 7, 19, 5, 5, 23, and 8, with a mean of 10.7.



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