The K7RA Solar Update


Due to the Thanksgiving holiday, the Solar Update is coming out two days early. Look for another update on Monday, November 28.

Not much in the way of solar excitement this week, except there are many sunspots, but the solar activity in terms of flares or coronal mass ejections is low. The overlapping (by one day) average sunspot numbers in this bulletin declined 21 points to 124. Sunspot numbers for November 16-22 were 126, 122, 137, 149, 101, 101 and 132, with a mean of 124. The 10.7 cm flux was 142.3, 147.7, 144.4, 139.6, 139.9, 141.1 and 142.4, with a mean of 142.5. The estimated planetary A indices were 2, 3, 2, 1, 2, 5 and 6, with a mean of 3. The estimated mid-latitude A indices were 3, 2, 1, 1, 2, 5 and 7 with a mean of 3.

We should see good conditions for the CQ Worldwide DX Contest, which runs this weekend (November 26-27). The latest prediction from USAF/NOAA shows the solar flux at 140 on November 23, 145 on November 24-27, 150 on November 28-29, 155 on November 30, 160 December 1-2, and 165 December 3-7. The predicted planetary A index is 5 on November 23-27, 7 on November 28-29, and then 5 on November 30-December 24.

Larry Goolsby, AA4JI, of Fayetteville, Tennessee wrote on November 18: “During the Triple H Net on 7.190 MHz at 0700 UTC this whole week, we have been working Central Australia with strong 57 reports. I repeatedly worked Bob, VK2NRB, and Peter, VK2TTP, using just 100 W and a wire dipole at 30 feet each morning. I am seeing Europe starting, along with some Asia contacts. New Zealand has been strong, as has V21N in Antigua.”

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 and 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.