Propagation de K7RA

Share

From Tad Cook, K7RA
Seattle, WA November 18, 2016

To all radio amateurs 

Solar flux and sunspot numbers moved in opposite directions over the past week, and differences were more extreme than usual. Normally we expect daily sunspot numbers and solar flux to track together, and geomagnetic indices to track with each other as well, at least approximately.

Average daily sunspot numbers over the past reporting week (November 10-16) rose 10 points from 18.7 to 28.7, while average daily solar flux dropped from 76.9 to 45.8. These comparisons express differences from the previous reporting week, November 3-9.

Over the same dates average planetary A index increased markedly from 6.4 to 12.7, while the mid-latitude A index changed from 4.3 to 10.1.

Predicted solar flux values for the near future are 79 on November 18, 78 on November 19, 80 on November 20-21, 78 on November 22-26, 80 on November 27, 82 on November 28 through December 1, 84 on December 2, 82 on December 3-7, 80 on December 8-9, 78 on December 10, 75 on December 11-15, 77 on December 16, 75 on December 17-21 and 78 on December 22-23.

The predicted planetary A index is 5, 16 and 18 on November 18-20, then 10, 48, 48, 36, and 28 on November 21-24, then 25, 18, 12, 10 and 8 on November 23-29, then 5 on November 30 til December 6, then 15, 12, 18, 20, 15 and 10 on December 7-12 and 5 on December 13-15, then 10, 15, 55, 45, and 25 on December 16-20, then 18, 25, 18, 12, 10 and 8 on December 21-26, and 5 over the following week.

http://www.spaceweather.com reports the solar cycle is currently at the lowest level in 5 years.

The ARRL Phone Sweepstakes is this weekend.
An expansion of Space Weather Services was announced at: http://bit.ly/2fk4Mot

Thanks to Max White and David Moore for the above tip.
Petr Kolman, OK1MGW of the Czech Propagation Interest Group sent his geomagnetic activity forecast for the period November 18 to December 14, 2016.

Geomagnetic field will be: Quiet on December 2-4, 13-14 Mostly quiet on November 18, December 1, 12 Quiet to unsettled on November 19, 27-30, December 5-6, 11 Quiet to active on November 20, 24, December 7-10 Active to disturbed on November 21-23, (25-26)

Amplifications of the solar wind from coronal holes are expected on November 20-26, December 7-10.

Parenthesis means lower probability of activity enhancement.
Jeff, N8II in West Virginia reports, “Saturday, November 12 I was able to work 24 each OK/OM Czech/Slovak stations on 15 meter CW (1352-1534Z) and 80 M in a non-serious contest effort (with 100W). On 15, I only worked one weak Slovak, but some Czechs were loud, very selective! Sunday, the contest was over at 1200Z and the 15 M band did not open east of Italy. I made the most QSOs on 20 with good conditions, but central EU closes early with the time of year and low SFI. 40 fades down quickly to EU after sunset.

“I just worked V63GW Micronesia with a good signal on 20M CW short path at 2032Z, expected him to be LP.

“Burma is now QRV and so far nil as expected in WV, best hope is 20 or 30M.

“Wednesday night, November 16 I worked ZD8W Ascension Island on 30 CW around 0100Z with S5-7 signal.

“Thursday 15 M was open as far north as northern Germany (Hanover) and I easily broke a EU pile up on FR4QF on Reunion Island on 15 SSB at 1522Z; he was peaking S9.”

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 web page at, http://arrl.org/propagation-of-rf-signals

For an explanation of the 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 November 10 through 16 were 13, 26, 51, 38, 26, 29, and 18, with a mean of 28.7. 10.7 cm flux was 80.2, 78.4, 78.4, 77.8, 77.3, 76.5, and 80.9, with a mean of 45.8. Estimated planetary A indices were 14, 13, 19, 21, 11, 7, and 4, with a mean of 12.7. Estimated mid-latitude A indices were 11, 10, 13, 19, 8, 7, and 3, with a mean of 10.1.

NNNN

/EX

Related posts