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The K7RA Solar Update

Tad Cook, K7RA, Seattle, reports: Solar activity slowed this week, with the average daily sunspot number declining from 48.9 last week to 33.9 this week (July 22 – 28). Wednesday, July 28, saw no sunspots at all.

Average daily solar flux went from 81.3 to 83.

Geomagnetic indicators held steady, with average daily planetary A index at 6.4 both last week and this week. Average daily middle latitude A index went from 6.4 last week to 6.3 this week.

Predicted solar flux is 76 on July 30 – 31; 74 on August 1; 72 on August 2 – 4; 74 on August 5 – 6; 75 on August 7 – 12; 78, 80, 82, and 85 on August 13 – 16; 90 on August 17 – 18; 85 on August 19 – 20; 80 on August 21; 82 on August 22 – 28; 78 on August 29, and 75 on August 30 – September 8.

Predicted planetary A index is 8, 12, and 8 on July 30 – August 1; 5 on August 2 – 9; 12 and 10 on August 10 – 11; 5 on August 12 – 15; 10 and 8 on August 16 – 17; 5 on August 18 – 23; 12, 12, and 8 on August 24 – 26; 5 on August 27 – 28; 8 on August 29, and 5 on August 30 – September 5.

F.K. Janda, OK1HH, is on vacation this week, hiking in the mountains of the Czech Republic, so we have forecasts from two of his associates. The first is from Martina Pavelkova, RWC Prague, Astronomical Institute, Solar Department, Ondrejov, Czech Republic.

Solar activity forecast for the period July 30 – August 05:

Activity level: mostly very low
X-ray background flux (1.0 – 8.0 A) in the range A5.5 – B1.5
10.7-centimeter radio flux: Fluctuating in the range 74 – 82
Events: Class C (0 – 4/period), Class M (0/period), Class X (0/period), Proton (0/period)
Relative sunspot number (Ri): in the range 0 – 55

Here’s a rgeomagnetic activity forecast for July 30 – August 5 from Tomas Bayer, RWC Prague, Institute of Geophysics of the ASCR, Prague, Department of Geomagnetism, Budkov Observatory (BDV).

Quiet: Jul 30 – 31, Aug 2 – 4
Unsettled: Jul 31, Aug 1 – 3, 5
Active: 0
Minor storm: 0
Major storm: 0
Severe storm: 0

Geomagnetic activity summary: Next week, we expect at most quiet to unsettled conditions. The more unsettled events are possible about August 1 – 2, and also about Thursday, August 5. The other days, we expect quiet to unsettled conditions generally, closer to quiet level.

Jan, KC0V, in Colorado, wrote to report a big 2-meter opening from DN70 to the midwest on the afternoon of July 24.

“I was busy with some chores then happened to look at DXMaps and the APRS VHF propagation map and noticed a large Es cloud located over eastern Nebraska and western Iowa and another over southeastern Kansas. I quickly tuned into 2 meters, FT8 144.174. Signals were very strong, with +21 dB the best report I sent and +29 dB the best report I received. My QSOs, beginning at 2216 and ending at 2235 UTC were:

WA9DU

EM69

WB8ART

EM79

AA9JS

EN51

KC9IKB

EM69

KA9CFD

EN40

WA4CQG

EM72

KX9X

EN50

NY1V

EM69

KM8V

EN91

K2DRH

EN41

AG4V

EM55

KO9A

EN52

WB8JCW

EN80

“Then followed 26 minutes of a mixture of single decodes, total quiet, meteor bursts, but no QSOs. Then at 2301 UTC, K9YK in EN60. And then it was over. I don’t know when the opening began since it was well in progress when I got to the radio, but it was an amazing 20 minutes or so.

“Unfortunately, I was unable to complete [a contact] with W3IP in FM19, which would have been the longest-distance QSO of the opening for me. We heard each other over several sequences but were unable to finish the exchange.

“My station: Kenwood TS-2000, Beko HLV-1000 running at 750 W, 10-element LFA (by G0KSC) at 35 feet.”

Sunspot numbers for July 22 – 28, 2021 were 77, 46, 35, 24, 25, 25, and 0, with a mean of 33.1. The 10.7-centimeter flux was 89, 87.4 83.9, 81.6, 80.8, 79.6, and 78.8, with a mean of 83. Estimated planetary A indices were 11, 4, 4, 3, 4, 6, and 13, with a mean of 6.4. Middle latitude A index was 9, 3, 5, 5, 3, 6, and 13, with a mean of 6.3. (arrl.org)

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