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SB PROP @ ARL $ARLP046
ARLP046 Propagation de K7RA

ZCZC AP46
QST de W1AW
Propagation Forecast Bulletin 46 ARLP046

From Tad Cook, K7RA

Seattle, WA December 2, 2024
To all radio amateurs

SB PROP ARL ARLP046
ARLP046 Propagation de K7RA

ARRL Headquarters was closed on November 29. So, this regular Friday bulletin was moved to the following Monday (12/2).


Solar activity increased during the current reporting week, November 21-27. Average daily sunspot number rose to 155.7, and average daily solar flux was 282.2.


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere - November 28, 2024, by F. K. Janda, OK1HH:


"After the unexpected solar proton flare of 21 November, which took place beyond the Sun's western limb, a rain of higher-energy protons hit the
Earth's atmosphere. This solar radiation storm had a greater impact at higher latitudes in the southern hemisphere, where it caused a significant increase
in attenuation.


"Two days later, two new large sunspot groups appeared near the southeastern limb of the Sun. These produced moderate eruptions daily, which is more or
less normal for the 11-year maximum. These are AR3905 and AR3906, which have grown rapidly to a size where they can be observed with the naked eye. There
is a relatively small coronal hole near them that could be influencing the solar wind enhancement.


"Following the eruption of a plasma filament near AR3901, a G2 class geomagnetic storm is possible on November 28-29, when a CME is expected to impact. However, around 1900 UT on November 28, when this information is written as usual, nothing is still happening. We will see what happens next.
It is quite possible that the plasma cloud will only hit the Earth a little
and it is also not out of the question that it will miss the Earth
completely. So, any prediction at this point has a low probability of coming true."


New video from Dr. Tamitha Skov, WX6SWW:
https://youtu.be/1P4sCwn8TZI [ https://youtu.be/1P4sCwn8TZI ]

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?utm_source=Informz&utm_medium=Email&utm_campaign=ARRL
] 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, "Understanding Solar Indices" from September 2002 QST.

https://bit.ly/3Rc8Njt [ https://bit.ly/3Rc8Njt ]

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


Sunspot numbers for November 21 through 27, 2024 were 148, 170, 156, 164,
140, 163, and 141, with a mean of 155.7. 10.7 cm flux was 166.2, 179.1,
199.9, 202.7, 220.4, 222.3, and 225, with a mean of 202.2. Estimated
planetary A indices were 8, 12, 8, 7, 11, 7, and 5, with a mean of 8.3.
Middle latitude A Index was 5, 10, 7, 7, 9, 6, and 3, with a mean of 6.7.

NNNN
/EX

ARRL(R) The National Association for Amateur Radio(R)
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