Over the past week, on Monday, October 21, 10.7 cm solar flux sunk to possibly the lowest level in recorded history. Solar flux was 64, which is even lower than the 64.4 value recorded way back on July 2, 1954 at the start of solar cycle 19, by far the biggest solar cycle ever recorded. I understand that solar flux dipped to 64.2 in 1906.
The average solar flux this past week was lower than the perhaps all-time lowest weekly average reported in this bulletin (66) back in ARLP035 in August: http://www.arrl.org/w1aw-bulletins-archive/ARLP035/2019
Over the recent reporting week, October 17-23, average daily solar flux was 65.3, two points lower than last week. Average daily planetary A index dropped from 6.4 to 4.7, while average daily mid-latitude A index declined from 5.1 to 3.1. And of course, there were no sunspots.
Predicted solar flux for the next 45 days is 65 on October 25 through November 1, and 66 on November 2 through December 8.
Predicted planetary A index is 30 and 18 on October 25-26, 15 on October 27-28, 8 on October 29, 5 on October 30 through November 16, then 15, 8 and 5 on November 17-19, then 20 and 24 on November 20-21, 15 on November 22-23, then 12 and 8 on November 24-25, and 5 on November 26 through December 8.
But even with such record low solar activity, HF propagation still exists, occasionally to a surprising degree. Recently it seems as if most of the HF propagation reports I receive involve the FT8 mode, which has a remarkable ability to dredge up signals from what sound like noise to our ears.
But I received a second-hand report from W7WA and K7CW who attended a ham club meeting a few days ago in Mason County, Washington where WA4ELK reported working Lithuania and Belarus on 10-meter SSB at 0900 UTC October 22 using low power and a bazooka antenna.
Certainly, an odd opening at an odd time of the day and I hope to track down more details.
Geomagnetic activity forecast for the period October 25-November 19, 2019 from F.K. Janda, OK1HH.
Geomagnetic field will be
Quiet on October 30, November 8-9, 12-14, 18-19
Quiet to unsettled on November 4-7, 10-11, 15-17
Quiet to active on October 28-29, 31, November 2-3
Unsettled to active on November 1
Active to disturbed October 25 (-27)
Solar wind will intensify on October 25-26, November (7-9,) 13, 21–23
Parenthesis means lower probability of activity enhancement.
Jon Jones, N0JK, reported from Kansas, an E-skip and trans-equatorial opening October 17-18 on 6 meters from North America to South America. “I didn't hear or work any South America. I worked on 6-meter Es NZ3M (FN10), N3BBI (FN20, W5PUF (rare DL99) and XE2JS (DL78). CX9AU spotted KF0M EM17 around 0030z on October 18.
“Today, October 24, strong solar wind from a coronal hole arrived in the afternoon causing aurora in Alaska. The Kp went to 4 and 10 Meters opened. The 5K0K DXpedition was loud on 28.430 MHz SSB into the Midwest and logged at 2043z. Twelve meters was also good, with ZD8SC 59 plus on 24.437 MHz, which I worked at 2039z. I was ‘fixed mobile’ with 100 watts and a 1/4 wavelength vertical antenna on each band. So far no enhanced conditions on 6 meters.”
Ken Brown, N4SO, reports from Alabama: "On October 20 I decoded a surprising number of stations in European Russia, Ukraine, Latvia, Lithuania, and the Slovak Republic on 17-meter FT8. Here is just a partial listing. The time is around 1400 UTC.
134715 -18 0.1 1633 CQ LY2GV KO15 Lithuania
140045 -18 0.4 2025 CQ YL2IP KO27 Latvia
140230 -4 0.5 1900 W1FNJ UX1IW KN87 (Serge, Donetsk, Ukraine)
140230 -15 0.4 2270 CQ NA RN3OG KO91 EU Russia
140230 -7 0.4 1605 CQ DX RA1AOB KO59 EU Russia
140545 -7 2.0 320 CQ NA UT7HA KN69 Ukraine
140615 -7 0.5 428 CQ OM2GM JN87 Slovak Rep.
140615 -6 0.3 1354 CQ DX UA6BRD LN05 EU Russia
“For Maritime Mobile on merchant ships, here is one more from Francois F5MYK/MM, contacted on 7.074 MHZ FT8, October 19. F5MYK info is on QRZ.com.
“How late does 18.100 MHZ FT8 stay open? I have decoded Hawaii KH6AQ at 0357 UTC working RZ9O.
22 October 035715 -18 0.2 1831 ~ RZ9O KH6AQ R-18
The usual closing for 18.100 MHZ is around 0100 UTC."
Here is a report from Danny, KB8W: "There was a nice Es and TEP opening on 6 meters Thursday evening. At about 0030Z on October 18 I checked 6-meter activity on the DXMaps website and was surprised to see lots of contacts indicated in the central and southeastern parts of the US. They were mostly 800 to 1000 miles long and appeared to be Es. There were also some longer contacts from the southeastern US to northern South America that looked like TEP. The site showed that most stations were using FT8 on 50.313 MHz.
“As I monitored the band, I started hearing stations (I live in EN57, in Michigan's Upper Peninsula). Over the next hour I worked four stations in Texas and Oklahoma:
0039Z K5GKC -13 -11 50313 50W FT8 EM13
0047Z W5PUF -9 -12 50313 50W FT8 DL99
0101Z KC5WX +8 -10 50313 50W FT8 EM13
0111Z WB5GVY -12 -14 50313 50W FT8 EM10
“For the next hour I heard WB5GVY working other stations and calling CQ, but I did not hear any other activity after 0115Z. The DXMaps website showed some activity that slowly faded away while the center of the activity moved west across the US. I stopped listening and went to bed at about 0400Z.
“I have been fairly active on 6 meters for the past 10 years, doing meteor scatter in the early morning hours, and then other modes later in the day. Sporadic E is very common during the summer months here in the far north central section of the US, it usually starts in early May and ends in late August. This year I had a short Es opening to Colorado and Arizona during the ARRL September VHF contest in mid-September. That was the first time in 10 years that I saw any Es activity in September. I have a very modest station on 6 meters – 100W to a homebrew 5 element Yagi antenna at about 13 feet up.”
If you would like to make a comment or have a tip for our readers, email the author at k7ra@arrl.net.
For more information concerning radio propagation, see the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals. For an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere.
An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation. More good information and tutorials on propagation are at http://k9la.us/.
Monthly propagation charts between four USA regions and twelve overseas locations are at http://arrl.org/propagation.
Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins
Sunspot numbers for October 17 through 23, 2019 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 66.1, 66.1, 66, 65, 64, 65.6, and 64.5, with a mean of 65.3. Estimated planetary a indices were 6, 6, 5, 6, 5, 3, and 2, with a mean of 4.7. Middle latitude A index was 4, 4, 3, 4, 4, 2, and 1, with a mean of 3.1.
http://www.arrl.org/news/the-k7ra-solar-update-600
