[SFDXA] ARLP020 Propagation de K7RA

Mon Jun 3 13:16:59 EDT 2024

/First notice I've seen in weeks.../

> SB PROP @ ARL $ARLP020
>
> ARLP020 Propagation de K7RA
>
> ZCZC AP20
>
> QST de W1AW
>
> Propagation Forecast Bulletin 20 ARLP020
>
> From Tad Cook, K7RA
>
> Seattle, WA May 31, 2024
>
> To all radio amateurs
>
> SB PROP ARL ARLP020
>
> ARLP020 Propagation de K7RA
>
> Solar activity was quiet this week. Average daily sunspot number 
> slipped from 155.1 to 124.6, and average solar flux from 198.9 to 164.8.
>
> Geomagnetic conditions were quiet, with average planetary A index 
> going from 13.9 to 7.9, and middle latitude A index from 11.7 to 9.
>
> Eight new sunspot groups emerged, one on May 23, two on May 25, four 
> on May 26, and one on May 28.
>
> The outlook for the next month predicts solar flux at 175 on May 31 
> through June 6, then 210, 200, 195, 190, 185 and 180 on June 7-12, 170 
> on June 13-14, 165 on June 15, 190 on June 16-17, 185 on June 18, then 
> 190 on June 19-20, then 185, 195 and 200 on June 21-23, then 210, 210 
> and 215 on June 24-26, 225 on June 27-29, 220 on June 30 through July 
> 1, 210 on July 2-4, then 200, 195 and 190 on July 5-7.
>
> Predicted planetary A index is 25 on May 31 and June 1, 5 on June 2-7, 
> then 10, 12, 8, 12 and 10 on June 8-12, 5 on June 13-19 then 15 and 12 
> on June 20-21, then 5, 12, 8 and 5 on June 22-25, and 5, 10, 12, 12 
> and 8 on June 26-30, then 5 on July 1-4, then 10, 12, 8, 12 and 10 on 
> July 5-9.
>
> Weekly Commentary on the Sun, the Magnetosphere, and the Earth's 
> Ionosphere from OK1HH.
>
> "Over the past seven days, two active regions have returned to the 
> solar disk where large solar flares with CMEs were observed during the 
> last solar revolution. These were regions AR3663 and AR3664, now 
> designated AR3691 and AR3697. The activity of the latter caused a 
> major geomagnetic storm with auroras on 10 May, the largest in 
> decades. Until these large groups of spots reach the center of the 
> solar disk or near the central meridian (i.e., approximately June 
> 6-7), solar activity will increase in a roughly 20-day fluctuation and 
> then decrease again.
>
> "Even the last major solar flare on May 29 afternoon UTC was observed 
> in AR3697 and was accompanied by a CME. Part of the particle cloud 
> will probably hit Earth sometime between late afternoon on June 1 and 
> the morning of June 2. The onset of the
>
> phenomenon should be accompanied by an improvement in shortwave 
> propagation conditions and a deterioration can be expected during its 
> continuation on June 2.
>
> "In the following days, due to increasing solar activity and a calmer 
> state of the Earth's magnetosphere, shortwave propagation should 
> improve again. However, if another large solar flare occurs, the 
> development could be much more dramatic. Another reason for the 
> current instability of shortwave conditions is the rise in Summer 
> sporadic-E layer activity in the northern hemisphere.
>
> Spaceweather.com 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzMQ/index.html> 
> reports NOAA forecasters say a G2 class geomagnetic storm is possible 
> on May 31 when a CME grazes earth. But a NASA forecast suggests a near 
> miss. This is from a CME at 1433 UTC on May 29 from sunspot group AR3664.
>
> More on sunspot group AR3664:
>
> https://bit.ly/4bAeJKA 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzMg/index.html>
>
> https://bit.ly/3wY48tT 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzMw/index.html>
>
> https://tinyurl.com/2p9c98tm 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzNA/index.html>
>
> https://tinyurl.com/mskr6ptb 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzNQ/index.html>
>
> https://tinyurl.com/ypnjcc6d 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzNg/index.html>
>
> https://tinyurl.com/2pvuk5db 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzNw/index.html>
>
> The latest video from Dr. Tamitha Skov, WX6SWW:
>
> https://youtu.be/O2Y9QGLMvsc 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzOA/index.html>
>
> Send your tips, reports, observations, questions and comments to 
> k7ra at arrl.net <mailto:k7ra at arrl.net>. When reporting observations, 
> don't forget to tell us which mode you were operating.
>
> For more information concerning shortwave radio propagation, see 
> http://www.arrl.org/propagation 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDYzOQ/index.html> 
> and the ARRL Technical Information Service web page at, 
> http://arrl.org/propagation-of-rf-signals 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDY0MA/index.html>. 
> For an explanation of numbers used in this bulletin, see
>
> http://arrl.org/the-sun-the-earth-the-ionosphere 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDY0MQ/index.html>.
>
> An archive of past propagation bulletins is at
>
> http://arrl.org/w1aw-bulletins-archive-propagation 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDY0Mg/index.html>. 
> More good information and tutorials on propagation are at 
> http://k9la.us/ 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDY0Mw/index.html>.
>
> Also, check this QST article about Solar Indices:
>
> https://bit.ly/3Rc8Njt 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDY0NA/index.html>
>
> Instructions for starting or ending email distribution of ARRL 
> bulletins are at http://arrl.org/bulletins 
> <https://arrl.informz.net/z/cjUucD9taT0zMDUxNTA0JnA9MSZ1PTUyNTQ3MzY2NCZsaT0zMzc1NDY0NQ/index.html>.
>
> Sunspot numbers for May 23 through 29 2024 were 130, 100, 106, 148, 
> 116, 141, and 131, with a mean of 124.6. 10.7 cm flux was 176.2, 
> 162.8, 152.4, 155.6, 170, 166.4, and 170.5, with a mean of 164.8. 
> Estimated planetary A indices were 10, 9, 6, 10, 8, 6, and 6, with a 
> mean of 7.9. Middle latitude A index was 10, 11, 6, 10, 9, 7, and 10, 
> with a mean of 8.
>
> NNNN
>
> /EX
>
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