The K7RA Solar Update


The day that last week’s bulletin was released --Friday, October 21 -- the daily sunspot number broke another record for Solar Cycle 24 when it rose to 207. You have to look back to November 26, 2003 when it was two points higher – 209 -- to find a number at least as high. But the average daily sunspot number for the week was off by two points to 156.6, while the average daily solar flux rose nearly 8 points to 151.8. How much higher will it go? The latest prediction shows sunspot activity peaking between February-July 2013, so there would seem to be plenty of opportunity for more daily sunspot readings of 207 and higher.

Sunspot numbers for October 20-26 were 195, 207, 164, 128, 151, 147 and 104, with a mean of 156.6. The 10.7 cm flux was 159.1, 167.8, 164.1, 155.5, 145.3, 138.8 and 132.2, with a mean of 151.8. The estimated planetary A indices were 5, 5, 3, 3, 23, 33 and 3, with a mean of 10.7. The estimated mid-latitude A indices were 3, 5, 2, 2, 16, 27 and 4 with a mean of 8.4.

Propagation on HF is quite exciting right now, with 10 meters opening up worldwide daily. Based on recent conditions, working the CQ World Wide SSB DX Contest this weekend should offer plenty of fun. The latest predicted solar flux is 130 on October 28-31, 125 on November 1, 120 on November 2-5, then 125 and 130 for November 6-7 and 135 on November 8-10. Flux values for the near term are expected to peak at 165 on November 17-18. The predicted planetary A index is 7, 8, 10 and 10 on October 28-31 and 5 on October 31-November 3, 8 on November 4-5, 5 on November 6-10 and 8 on November 11-13. Geophysical Institute Prague predicts quiet to unsettled conditions October 28, unsettled October 29, quiet to unsettled for October 30 and quiet October 31-November 3.

A week ago (October 21), we received this update from Jeff Hartley, N8II, of Shepherdstown, West Virginia, and in the first part he was referring to the sunspot number reaching 195 the day before: “Whoo hoo! Actually, things sounded a bit better the two days prior to last night. It's fairly commonplace at 2100 to hear Japanese and Western European stations at the same time on 12 meters! I had a solid QSO (S5) with BG4AEC (China) running 100 W and a vertical on 10 meters SSB around 0015 on October 19, past the peak of propagation. It's hard to get much done because the radio is too much of a draw! Unfortunately, the flooding in Southeast Asia seems to be keeping the rare countries (XV,XU,XZ) off the air. K3ZO is in Thailand but unable operate much because HS0AC is being used for emergency communications. Cars are being parked on bridges and upper levels of garages to avoid the flooding! I hear 9M6XRO almost daily on either 12 or 10 meters.”

Speaking about the Draconids meteor shower, Jon Jones, N0JK, of Wichita, Kansas, wrote: “The Draconids would have been big news a year ago on VHF, but with all the F2 and TEP being worked on 6M this fall, it kind of puts the Draconids meteor shower on the back burner. One important ‘lesson’ from it is the astronomer's predictions of meteor shower outbursts are much better now and more accurate.”

Check this video of some solar events a few days ago:.

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.