ARLP042 Propagation de K7RA

SB PROP @ ARL $ARLP042
ARLP042 Propagation de K7RA

ZCZC AP42
QST de W1AW
Propagation Forecast Bulletin 42 ARLP042

From Tad Cook, K7RA

Seattle, WA November 1, 2024
To all radio amateurs

SB PROP ARL ARLP042
ARLP042 Propagation de K7RA

Solar activity increased this week. Average daily sunspot number went from
127.7 to 197.4 and average solar flux from 170.5 to 240.2.


Predicted solar flux is 270 on November 1-2, 265 and 260 on November 3-4, 250
on November 5-7, 214, 195 and 182 on November 8-10, 172, 168, 174 and 165 on
November 11-14, and 162 on November 15-16.


Predicted planetary A index is 5, 8, 15, and 10 on November 1-4, 5 on
November 5-15, then 5, 8, 5, 12, and 8 on November 16-20, and 5 on November
21 through December 5


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere -
October 31, 2024 from OK1HH:


"We know only approximately what the Earth's ionosphere looked like between
March 1755 and June 1766 thanks to observations of the Sun in Solar Cycle 1.
But we do know what it looked like in Solar Cycle 19, which ran from April
1954 to October 1964. Although I was a novice radio amateur at the time, I
can testify that the shortwave propagation conditions at the peak of Solar
Cycle 19 (1958) were wonderful!


"As of December 2019, Solar Cycle 25 is in operation. It was supposed to be
low, fortunately it is not. Its maximum is now underway, perhaps a second
will follow next year. It is fabulous, judging by the above and the many
interesting effects, including, for example, auroras. But unfortunately, not
if we judge them by the current conditions of ionospheric shortwave
propagation. An explanation of why this is now the case will surely be
forthcoming - but perhaps Solar Cycle 26 will be underway.


"A week ago, as expected, large active regions and corresponding groups of
spots appeared at the southeastern limb of the solar disk. We are now seeing
them near the central meridian. This has increased the likelihood of Earth
being hit by particles that will eject subsequent flares. It seems that not
only these, but also disturbances in the geomagnetic field and then
fluctuations in the ionospheric propagation field can be counted on with
certainty in the coming days. Given that we have already seen simultaneously
observed active regions on the Sun during the last solar rotation, presumably
a 27-day recurrence will be a good aid to prediction."


How NASA tracks the Solar Cycles:
https://www.dailymotion.com/video/x98c2di [
https://www.dailymotion.com/video/x98c2di ]


The latest from the Solar-Terrestrial Centre of Excellence Newsletter:
https://www.stce.be/newsletter/newsletter.php [
https://www.stce.be/newsletter/newsletter.php ]


Send your tips, reports, observations, questions and comments to
k7ra@arrl.net [ mailto:k7ra@arrl.net ] . When reporting observations, don't
forget to tell us which mode you were operating.


For more information concerning shortwave radio propagation, see
www.arrl.org/propagation [ http://www.arrl.org/propagation ] and the ARRL
Technical Information Service web page at,
www.arrl.org/propagation-of-rf-signals [
http://arrl.org/propagation-of-rf-signals ] . For an explanation of numbers
used in this bulletin, see www.arrl.org/the-sun-the-earth-the-ionosphere [
http://arrl.org/the-sun-the-earth-the-ionosphere ] .


An archive of past propagation bulletins is at
www.arrl.org/w1aw-bulletins-archive-propagation [
http://arrl.org/w1aw-bulletins-archive-propagation ] .


More good information and tutorials on propagation are at http://k9la.us [
http://k9la.us/ ] .


Also, check this article:
https://bit.ly/3Rc8Njt [ https://bit.ly/3Rc8Njt ]
"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL bulletins are
at www.arrl.org/bulletins [ http://arrl.org/bulletins ] .


Sunspot numbers for October 24 through 30 2024 were 138, 157, 181, 198, 288,
220, and 200, with a mean of 197.4. 10.7 cm flux was 196.6, 209.3, 238.4,
246.2, 255.5, 265.6, and 269.8, with a mean of 240.2. Estimated planetary A
indices were 13, 3, 14, 10, 17, 12, and 15, with a mean of 12. Middle
latitude A Index was 10, 2, 11, 8, 11, 10, and 10, with a mean of 8.9.

NNNN
/EX

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