[SFDXA] ARLP021 Propagation de K7RA

[Bill]

  SB PROP @ ARL $ARLP021

ARLP021 Propagation de K7RA

ZCZC AP21

QST de W1AW

Propagation Forecast Bulletin 21 ARLP021

 From Tad Cook, K7RA

Seattle, WA June 7, 2024

To all radio amateurs

SB PROP ARL ARLP021

ARLP021 Propagation de K7RA

This reporting week (May 30 to June 5) our Sun was active, with nine new 
sunspot groups.

One emerged on May 30, another on May 31, two more on June 1, another on 
June 2, three more on June 3, and one more on June 4.

Average daily sunspot number rose from 124.6 to 183.4, and average daily 
solar flux from 164.8 to 184.8.

Predicted solar flux is 190 on June 7-9, 170 on June 10-19, 180 on June 
20, 190 on June 21-23, 195 on June 24 and 25, 200 on June 26, 205 on 
June 27-29, 180 on June 30, then 185, 185 and 180 on July 1-3, 175 on 
July 4-7, 180 and 175 on July 8-9, and 170 on July 10-16.

Predicted planetary A index is 5, 10 and 8 on June 7-9, 5 on June 10-18, 
8 on June 19-20, then 5, 8 and 8 on June 21-23, and 5 on June 24 to July 
6, then 8, 10, and 8 on July 7-9, and 5 on July 10-15.

Weekly Commentary on the Sun, the agnetosphere, and the Earth's 
Ionosphere - June 6, 2024 from F.K. Janda, OK1HH:

"The rise in solar activity is confirmed by the average sunspot number 
for May, 171.7, which is the highest in 22 years. Plugging this into the 
formula for calculating the smoothed 12-month average gives 127.8 for 
last November. As a consequence of the high solar activity, including 
CME flares, there were a large number of geomagnetic storms in May. The 
largest of these occurred on 10-11 May, while accompanied by auroras, 
easily observable even at

mid-latitudes.

"Shortwave conditions were above average on only six days out of the 
entire month of May, and mostly poor on half of the days in response to 
a total of seven one- to three-day disturbed intervals. The worst day 
was May 11. In addition, a summertime sporadic-E layer contributed to 
the erratic development, especially in the mid-latitudes of the Northern 
Hemisphere.

"While the two large sunspot groups, AR3663 and AR3664 (AR3691 and 
AR3697 in June), continue to have a magnetic configuration conducive to 
the production of large flares, there are fewer of them than in May, and 
the evolution of propagation conditions is therefore more regular, and 
the occurrence of above-average days is more frequent.

The number of sunspot groups increased from seven to twelve during the 
first six days of June.

"Although the sunspot number and the solar flux (which is the power flux 
of solar radio noise at the 10.7 cm wavelength) may still be increasing, 
a repeat of the large disturbances experienced in May is unlikely in the 
near term."

On June 3, Glenn Packard, K4ZOT, wrote:

"I just received your Propagation Report and was reading it when a near 
miracle happened. Hawaii 6M FT8 station (KH6HI) came in on my JTAlert 
program here - South of Atlanta, GA - 06/3. Also, worked several west 
Coast stations (VE7DX, KF7PG, etc.) as well in rapid succession before 
the band changed. Very rare indeed to even hear a HI station in Atlanta."

An article about Astrophotographer Andrew McCarthy:

https://mymodernmet.com/andrew-mccarthy-sunspot-time-lapse/

The latest report from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/8WzEbOeWVfk

Send your tips, reports, observations, questions and comments to 
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 and the ARRL Technical Information 
Service web page 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/.

Also, check this QST article about Solar Indices:

https://bit.ly/3Rc8Njt

Instructions for starting or ending email distribution of ARRL bulletins 
are at http://arrl.org/bulletins.

Sunspot numbers for May 30 through June 5, 2024 were 144, 135, 194, 186, 
208, 224, and 193, with a mean of 183.4. 10.7 cm flux was 172.9, 179.4, 
188, 179.8, 186, 192.3, and 195.3, with a mean of 184.8. Estimated 
planetary A indices were 8, 12, 5, 5, 11, 8, and 7, with a mean of 8. 
Middle latitude A index was 10, 14, 6, 5, 13, 8, and 10, with a mean of 9.4.

NNNN

/EX
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