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The K7RA Solar Update


Five new sunspot groups appeared in the past nine days, and the average daily sunspot number for the November 11-17 period rose nearly 28 points from the week before to 60.9. The average daily solar flux was up nearly four points to 87.9. Sunspot numbers for November 11-17 were 48, 68, 63, 69, 62, 55 and 61, with a mean of 60.9. The 10.7 cm flux was 84.5, 85.4, 85.4, 86.4, 90.8, 91.8 and 91.2, with a mean of 87.9. The estimated planetary A indices were 15, 15, 8, 7, 7, 6 and 4, with a mean of 8.9. The estimated mid-latitude A indices were 12, 9, 4, 5, 5, 4 and 3, with a mean of 6.

The current forecast from NOAA/USAF shows a planetary A index of 5 on every day through the end of November, and the predicted solar flux on November 19 at 86, 84 on November 20-24, 82 on November 25-26 and then 80 through the end of the month. Geophysical Institute Prague has a somewhat different outlook from NOAA/USAF: They see quiet geomagnetic conditions for November 19-20, quiet to unsettled November 21, unsettled November 22-23 and quiet again on November 24-25. Conditions should be good during the ARRL Phone Sweepstakes this weekend. Latest predictions show continued solar activity with low geomagnetic activity levels.

Dean Straw, N6BV, gave a presentation in October at Pacificon 2010 entitled Seeing the HF Propagation Big Picture. Download the file, and be sure to click through pages 11-14 to see the predicted propagation shifting over time.

Note that the images from the STEREO mission now show nearly the entire Sun. This weekend the project achieves 97 percent coverage of the Sun.

Patrick Weatherford, AE5PW, of Newport, Arkansas (about 70 miles west-northwest of Memphis) wrote to tell us of the fun he had on the air on Thursday. Running 100 W from a ground-mounted vertical, from 2106-2156 UTC on 20 meter SSB, he worked PJ5/SP6IXF in St Eustatius and Saba Island, VP2V/NY6X on 20 meters CW in the British Virgin Islands, PJ5/SP6EQZ on 15 meter sCW, YV5AEA in Venezuela on 15 meters PSK31, J29WTA on 17 meters SSB in Dominica, YL2SW/MM near Nigeria on 17 meters CW, C5OC on 20 meters SSB in The Gambia and KH2/N2NL on 17 meters CW in Guam. Following that, he worked both Central and South American stations on 20 meters PSK31. Conditions have been helped by the increased sunspot numbers.

Jon Jones, N0JK, in Wichita, Kansas wrote to tell us about sporadic E-skip on 6 meters on November 13. He worked K6JSV at 2028 UTC on 50.125 MHz, from DM12 to EM18. There were reports of a number of beacons copied. N0LL/B in EL09QL was copied by WA5IYX in EM09OW, K7EK/B in DM43 was copied by AC7XP in CN87 and XE2K/B in DN17NT was copied by W7MEM in DM22.

On November 14, Dave Sarault, N3XF, experienced a great opening on 10 meters. He was operating WP2B in the US Virgin Islands. Dave wrote: “Today, November 14, I was operating from Brad’s station and experienced the best 10 meter opening I can remember in several years. I ran a pile up from 2015-2125, with signals from W1 and W2 running 40 dB over S9 from stations running 100 W into verticals and dipoles. Also, I was able to work mobiles who were stepping over guys running big beams! It reminded me of 10 meters in the glory days a few Solar Cycles ago. The band changed quickly, and at 2100, I worked several W6s, but that lasted about 15 minutes and they were gone.”

Check out the interesting narrative about stealth operation at West Point by WP2B.

Next week for the Thanksgiving holiday, this bulletin will be on a different schedule. Only the version of the bulletin linked from the home page will go up on Friday, November 26. The bulletin won’t be e-mailed to readers or transmitted from W1AW until Monday, November 29.

All times listed are UTC, unless otherwise noted.

Amateur solar observer Tad Cook, K7RA, of Seattle, Washington, provides this weekly report on solar conditions and propagation. This report also is available via W1AW every Friday, and an abbreviated version appears each Thursday in The ARRL Letter. You can find a guide to articles and programs concerning propagation here. Check here for a detailed explanation of the numbers used in this bulletin. An archive of past propagation bulletins can be found here. You can find monthly propagation charts between four USA regions and 12 overseas locations here. Readers may contact the author via e-mail.



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