K7RA Solar Update

The following is quoted from ARRL News:

12/19/2019

Tad Cook, K7RA, Seattle, reports: It’s been 36 consecutive days with no sunspots. Geomagnetic conditions were quiet until a minor solar wind stream hit on December 18, driving the planetary A index to 13 from the low single digits earlier in the week.

The average planetary A index for December 12 – 18 rose to 4.6, from 3.7 over the previous 7 days, while mid-latitude A index increased from 1.9 to 4. Predicted solar flux over the next 45 days is 70. The predicted planetary A index is 10, 8, and 8 on December 19 – 21; 5 on December 22 – January 4; 8 on January 5; 5 on January 6 – 8; 8 on January 9 – 10; 5 on January 11 – 13; 12 on January 14; 10 on January 15 – 17; 5 on January 18 – 31, and 8 on February 1.

Because of weak solar activity, the ARRL 10 Meter Contest last weekend was rather slow. QST‘s “The World Above 50 MHz” editor Jon Jones, N0JK, in Kansas said he encountered a strong opening to Argentina and Chile on Sunday. He said the propagation mechanism appeared to be sporadic E. More details in the weekly bulletin on December 20.

Sunspot numbers for December 12 – 18 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. The 10.7-centimeter flux was 70.5, 68.9, 70.3, 71, 70, 70.5, and 70.2, with a mean of 70.2. Estimated planetary A indices were 4, 4, 3, 5, 1, 2, and 13, with a mean of 4.6. Middle latitude A index was 3, 3, 2, 5, 1, 2, and 12, with a mean of 4.

A comprehensive K7RA Solar Update is posted Fridays on the ARRL website. 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.

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Website: ARRL News