SB PROP @ ARL $ARLP034
ARLP034 Propagation de K7RA
ZCZC AP34
QST de W1AW
Propagation Forecast Bulletin 34 ARLP034
From Tad Cook, K7RA
Seattle, WA August 23, 2019
To all radio amateurs
SB PROP ARL ARLP034
ARLP034 Propagation de K7RA
Spotless days continue this week, with consecutive days without
sunspots now at 16 days, according to spaceweather.com as of August
22.
Average daily solar flux for all practical purposes was unchanged,
from 67.4 last week to 67.5 this week. Average daily planetary A
index went slightly lower from 6.3 to 4.4.
Predicted solar flux looks the same as it has been for months now,
at 67 on August 23 to September 11, 68 on September 12 to 21 and 67
again on September 22 through October 6.
The forecast for planetary A index stands at 5 on August 23 to 25,
then 12, 12 and 8 on August 26 to 28, 5 on August 29 to 31, then
with a recurring coronal hole, 38 and 14 on September 1 and 2, 5 on
September 3 to 5, 8 on September 6 and 7, then 5 on September 8 to
15, 7 on September 16 and 17, 6 on September 18, 5 on September 19
to 21, 8 on September 22 to 24, 5 on September 25 to 27, then with
the return of that coronal hole 38 and 14 on September 28 and 29, 5
on September 30 through October 2, 8 on October 3 and 4 and 5 on
October 5 and 6.
Geomagnetic activity forecast for the period August 23 to September
18, 2019 from F. K. Janda, OK1HH who has issued weekly forecasts
since January, 1978.
"Geomagnetic field will be:
Quiet on: September 4 and 5, 9 to 15
Quiet to unsettled on: August 29 to 31, September 3, 6 to 8
Quiet to active on: August (23 to 25,) September 16 to 18
Unsettled to active on: August (26 to 28), September 2
Active to disturbed: September 1
Solar wind will intensify on: August 27 to 29, (30 and 31,)
September 1 and 2, (4 to 7)
Parenthesis means lower probability of activity enhancement."
There was an error in last week's bulletin, in which we
misidentified a call sign from Reunion Island when it was really St.
Pierre et Miquelon. Because of the proximity to Nova Scotia, I
always thought it part of Canada, but it is really a French
possession.
Ken, N4SO reports working XP3A (Greenland) with FT8 on 18.1 MHz, a
new one for him.
Interesting course from WX6SWW about indices:
https://www.youtube.com/watch?v=zVgZQqUYemc
And her latest forecast:
https://youtu.be/GlpdWxXUnAk
Curious about spotless days?
http://www.sidc.be/silso/spotless
Note that 1954 had more spotless days than last year, and it was
just prior to the biggest solar cycle (cycle 19) in recorded
history.
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 August 15 through 21, 2019 were 0, 0, 0, 0, 0,
0, and 0, with a mean of 0. 10.7 cm flux was 67.6, 67.5, 68, 67.5,
67.7, 67.3, and 66.8, with a mean of 67.5. Estimated planetary A
indices were 4, 5, 4, 6, 4, 4, and 4, with a mean of 4.4. Middle
latitude A index was 4, 6, 6, 7, 4, 7, and 5, with a mean of 5.6.
NNNN
/EX
