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The K7RA Solar Update

09/13/2019

No sunspots this week. Average daily sunspot numbers declined from 3.4 to zero. At the same time, average daily solar flux rose from 67.4 to 69.4.

Geomagnetic activity quieted, with average daily planetary A index declining from 19.9 to 8.9, while average daily mid-latitude A index went from 16.7 to 7.7.

Predicted solar flux is 68 on September 13-22, 69 on September 23 through October 5, 68 on October 6-19, 69 on October 20-24, 68 on October 25 and 69 on October 26-27.

Predicted planetary A index is 5 on September 13-22, 8 on September 23, 5 on September 24-25, then 10, 35, 45, 20 and 10 on September 26-30, then 8, 10 and 8 on October 1-3, 5 on October 4-19, 8 on October 20, 5 on October 21-22, then 8, 25, 30, 18 and 8 on October 23-27.

Geomagnetic activity forecast for the period September 13 until October 9, 2019 from F.K. Janda, OK1HH.

Geomagnetic field will be
Quiet on: September 14-16, 20 (-21,) November 8-9
Quiet to unsettled on: September 13, 17-19, 22, (24,) November 4-7
Quiet to active on: September 23, 25, 30, November 1-3
Unsettled to active on: September (26)
Active to disturbed: September (27-29)

Solar wind will intensify on: September 16, (24-27,) 28-30. October 1 (-4, 7-9)

-Parenthesis means lower probability of activity enhancement.
-The predictability of changes remains lower at present.

Jon Jones, N0JK, wrote: "There was some sporadic-E skip on 6 meters September 1 from the Midwest to Mexico to W6 and W7. From Kansas, I worked XE2OR in Mexico, and several stations in Arizona and California.

“On September 7, stations in New England worked the Gulf Coast. The Es may have been associated with active geomagnetic field conditions."

Ken Brown, N4SO, of Grand Bay, Alabama reports on his recent FT8 contacts on 17 and 40 meters: "Seventeen meters remains stable and a very good daylight band for DX. Here is a sample of contacts on the FT8 digital mode.

18.100 FT8  Sept. 11

135800 -15  0.1 1795   N4SO SP9DWT RR73 (Poland)
170830 -17  0.3 1278   N4SO 5B4ALJ RR73  (Mike in Cyprus)
170900 -16  0.4  779   CQ AL ON5CD JO20   Belgium  (Note calling CQ for Alabama.
171130 -11  0.4  779   N4SO ON5CD RR73  
171700 -16  0.2 1676   CQ MM0CEZ IO75     Scotland

“Forty meters remains an excellent band for DX contacts during the night with a world-wide range of countries on the FT8 digital mode:

7.074 FT8  Sept. 9

131415  -1  0.5 1705   CQ KH2L QK23       Guam
132945  -9  0.1 2340   N4SO KH2L R-23
133000  Tx      2378   KH2L N4SO RR73"

Mike, K6THZ, in Santa Clara, California reports unexpected propagation on 15 meters via FT8 late at night, including a QSO with Norway.

If you would like to make a comment or have a tip for our readers, email me 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 September 5 through 11, 2019 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 68.3, 68.9, 73.9, 67.5, 68.8, 70, and 68.1, with a mean of 69.4. Estimated planetary A indices were 14, 8, 7, 10, 14, 4, and 5, with a mean of 8.9. Middle latitude A index was 11, 9, 6, 9, 11, 4, and 4, with a mean of 7.7.

 



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