09/27/2024

Seven sunspot groups emerged this week. The first was on September
19, three on September 20, one each on September 22 and 23, and the
last on September 25.

Average daily sunspot numbers increased from 120 to 137.2, and
average daily solar flux shifted from 175.7 to 164.3.

Geomagnetic numbers were much quieter. Average daily planetary A
index changed from 35.7 to 14.3, and middle latitude A index from
23.4 to 10.7.

Predicted solar flux is 180 September 27 to October 1, 190 on
October 2-6, 185 on October 7-9, 180 on October 10, 175 on October
11-16, 170 on October 17-18, 165 on October 19, 160 on October
20-23, 165 on October 24-26, then 170 and 175 on October 27-28, 180
on October 29-30, and 190 on October 31 through November 2.

Predicted planetary A index is 5 on September 27-28, 8 on September
29-30, 5 on October 1-4, 10 on October 5-6, 5 on October 7-9, then
10, 20 and 19 on October 10-12, and 5 on October 13-21, 8 on October
22-23, 5 on October 24-31, and 8 on November 1-2.

"Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - September 26, 2024 from OK1HH:

"Solar flare activity is generally lower than it was in the first
half of September, when M-class solar flares were common and X-class
flares also occurred. The last significant M-class flare, including
a CME, was observed on September 22. However, the Earth's magnetic
field activity increased on September 25-26, incidentally in good
agreement with the forecast.

"Propagation conditions, especially in the shorter half of the
shortwave range, have understandably improved, but not as much as we
might have expected in the run-up to the equinox. This was
influenced by a decrease in solar activity (compared to August
levels) - and of course an increase in geomagnetic activity.

"Unlike in times relatively recently past, any of us can monitor not
only total solar activity, but also changes in solar wind
parameters. Both its speed and the concentration of free electrons
and protons ejected by flares. Changes in the ionosphere follow
quickly, but not always in the same way. It is also always the
result of previous developments."

Latest report from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/B9jWbAVEpZw[1]

Send your tips, reports, observations, questions and comments to k7ra@arrl.net[2]. 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[3] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[4] . For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[5] .

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[6] . More good
information and tutorials on propagation are at http://k9la.us/[7] .

Also, check this article:

https://bit.ly/3Rc8Njt[8] "Understanding Solar Indices" from September
2002 QST.

Instructions for starting or ending email subscriptions to ARRL
bulletins are at http://arrl.org/bulletins[9] .

Sunspot numbers for September 19 through 25 2024 were 109, 113, 117,
114, 224, 123, and 160, with a mean of 137.1. 10.7 cm flux was
161.2, 153.8, 158, 162.8, 167.4, 172.4, and 174.2, with a mean of
164.3. Estimated planetary A indices were 20, 7, 6, 5, 13, 17, and
32, with a mean of 14.3. Middle latitude A Index was 15, 6, 6, 3, 9,
12, and 24, with a mean of 10.7.


[1] https://youtu.be/B9jWbAVEpZw
[2] mailto:k7ra@arrl.net
[3] http://www.arrl.org/propagation
[4] http://arrl.org/propagation-of-rf-signals
[5] http://arrl.org/the-sun-the-earth-the-ionosphere
[6] http://arrl.org/w1aw-bulletins-archive-propagation
[7] http://k9la.us/
[8] https://bit.ly/3Rc8Njt
[9] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

10/04/2024

ASWFC GEOMAGNETIC DISTURBANCE WARNING ISSUED AT 0042UT/04 OCTOBER 2024 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.

Two coronal mass ejections first observed on 01-Oct and 03-Oct are
expected to impact Earth over 04-05 Oct. Lack of analyzable corona
graph imagery makes arrival time predictions uncertain.

INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS EJECTION FROM 04-06 OCTOBER 2024.

GEOMAGNETIC ACTIVITY FORECAST:
04 Oct:ÿ G3, chance of G4
05 Oct:ÿ G3, chance of G4
06 Oct:ÿ G1-G2

New sunspot groups emerged on every day over the past week. Two new
regions appeared on September 26, another on September 27, two more
on September 28, another on September 29, another on September 30,
three more on October 1 and another on October 2, for a total of
eleven.

Average daily sunspot number rose from 137.1 to 164.7, and average
daily solar flux from 164.3 to 213.1. Average daily planetary A
index shifted from 14.3 to 9.6.

Predicted solar flux is 310 on October 4-6, 300 on October 7, 290 on
October 8-10, 175 on October 11-16, 170 on October 17-21, then 175,
180, 185, 190 and 195 on October 22-26, then 200 on October 27-29,
205 on October 30 through November 4, then 200 and 185 on November
5-6 and 175 on November 7-12.

Predicted planetary A index is 54, 94, 72, 22 and 15 on October 4-8,
5 on October 9-10, then 20 and 19 on October 11-12, then 5 on
October 13-21, then 28 and 10 on October 22-23, 5 on October 24-26,
and 10 on October 27, then 5 on October 28-31, 10 on November 1-2, 5
on November 3-5, then 10, 20, and 19 on November 6-8, and 5 on
November 9 and the foreseeable future.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - October 3, 2024 from OK1HH:

"After AR3811 disappeared from our field of view behind the
southwestern limb of the solar disk on September 12, it was
continuously tracked by helioseismological methods until September
29, when it reappeared in the southeast, numbered AR3842. Its size
and activity on the far side of the Sun suggested that we could look
forward to a lot of activity in October.

"And so, it did. When solar flare X7.1/2b was observed on October 1
with a maximum at 2220 UT, the second largest in the current 11-year
cycle, I planned to start with this announcement. But when flare
X9.05, newly the largest in X-ray intensity in the same AR3842, was
observed on October 3 at 1218 UT, that was no longer the case.

"The source region of AR3842 was heading straight towards us. So,
the plasma cloud was probably heading directly for our ionosphere.
Unlike the aforementioned X7.1/2b (which thus moved to the third
largest), it is very likely that the CME of October 3 will hit
Earth. We therefore expect a disrupted end of the week.

"This weekend we can expect low MUF and high LUF on shortwave and
QSOs over aurora on VHF. Early next week will see a gradual return
to average and then above average radio wave propagation conditions
in the ionosphere."

From "The New Zealand Herald," Aurora in Auckland:

https://bit.ly/3NcNOde[1]

Radio Blackout hits U.S.:

https://bit.ly/3zNlkno[2]

https://www.space.com/sun-monster-solar-flare-x7-video[3]

Here is the latest update from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/QDf6eyTCbe4[4]

Send your tips, reports, observations, questions and comments to k7ra@arrl.net[5]. 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[6] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[7]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[8] .

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[9] . More good
information and tutorials on propagation are at http://k9la.us/[10] .

Also, check this article:

https://bit.ly/3Rc8Njt [11]

"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL
bulletins are at http://arrl.org/bulletins[12] .

Sunspot numbers for September 26 through October 2 2024 were 189,
122, 148, 154, 150, 196, and 194, with a mean of 164.7. 10.7 cm flux
was 181.1, 186, 194.5, 197.2, 214.2, 244.6, and 274.4, with a mean
of 213.1. Estimated planetary A indices were 13, 7, 7, 16, 11, 6,
and 7, with a mean of 9.6. Middle latitude A Index was 11, 5, 5, 17,
5, 9, and 6, with a mean of 8.3.

ÿ


[1] https://bit.ly/3NcNOde
[2] https://bit.ly/3zNlkno
[3] https://www.space.com/sun-monster-solar-flare-x7-video
[4] https://youtu.be/QDf6eyTCbe4
[5] mailto:k7ra@arrl.net
[6] http://www.arrl.org/propagation
[7] http://arrl.org/propagation-of-rf-signals
[8] http://arrl.org/the-sun-the-earth-the-ionosphere
[9] http://arrl.org/w1aw-bulletins-archive-propagation
[10] http://k9la.us/
[11] https://bit.ly/3Rc8Njt
[12] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

10/14/2024

Thanks to Carl, K9LA for contributing to this week's bulletin.

"SUBJ: ASWFC GEOMAGNETIC DISTURBANCE WARNING ISSUED AT 2220 UTC/10 OCTOBER 2024 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.

"A halo CME first observed on 09-Oct arrived at Earth at 10/1515UT, resulting in G4 geomagnetic conditions on 10-Oct. G4 geomagnetic conditions are expected on 11-Oct, with a chance of G5. G2 geomagnetic conditions are expected on 12-Oct, with a chance of G3 due to ongoing CME effects.

"INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS EJECTION FROM 11-13 OCTOBER 2024

"GEOMAGNETIC ACTIVITY FORECAST

11 Oct: G4, chance of G5

12 Oct: G2, chance of G3

13 Oct: G0-G1"

Only four new sunspot groups emerged this week. The first was on October 4, another on October 6 and two more on October 7.

Average daily sunspot number moved from 160 (Sep 26-Oct 2 period) to 182 (Oct 3-9 period), and average daily solar flux from 199 to 270.

Predicted solar flux is 215 on October 11-13, 210 on October 14-15, 200 and 205 on October 16-17, and 170 on October 18-21, then 175, 180, 185, 190, 195, 215, 230, 240, 250 and 255 on October 22-31, then 230 and 215 on November 1-2, then 205 on November 3-4, 200 and 185 on November 5-6, 175 on November 7-12, and 170 on November 13-17.

Predicted planetary A index reveals a huge disturbance at 122, 42, 12 and 12 on October 11-14, 5 on October 15-21, then 15, 10, 5, 5, 12 and 8 on October 22-27, 5 on October 28 til November 2, 12 and 8 on November 3-4, 5 on November 5-7, 8 on November 8, and 5 on November 9-17.

"Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere for October 10, 2024 from OK1HH.

"During the first ten days of October, the number of sunspot groups dropped from eleven to five, but the eruptive activity of the two largest sunspot groups did not decrease. Not only are moderate flares (M-classes, of which 34 were observed) frequent, but large events (X-classes) are also relatively common (five effects were observed, including one proton flare on 9 October). Several CMEs (coronal mass ejections) were also observed.

"After the two most active regions in particular moved to the western half of the solar disk, geomagnetic activity has increased significantly since 6 October. The most significant impacts on the state of the ionosphere were on 8 October. This will be followed by a very slow return to normal, lasting several days. A calm development can be expected after mid-October."

Reader Allison King sent this: https://nyti.ms/3YiNZtP[1]

David Moore sent this. A new era of solar observation: https://www.sciencedaily.com/releases/2024/10/241003145438.htm[2]

Send your tips, reports, observations, questions and comments to k7ra@arrl.net[3]. ÿWhen 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[4] ÿand the ARRL Technical Information Service web page at, http://arrl.org/propagation-of-rf-signals[5] ÿ

For an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[6] .

An archive of past propagation bulletins is at

http://arrl.org/w1aw-bulletins-archive-propagation[7] ÿ.

More good information and tutorials on propagation are at http://k9la.us/[8]

Also, check this. "Understanding Solar Indices" from September 2002 QST. https://bit.ly/3Rc8Njt[9]

Instructions for starting or ending email subscriptions to ARRL bulletins are at http://arrl.org/bulletins[10] .

Sunspot numbers for October 3 through 9 2024 were 194, 229, 180, 173, 167, 164, and 165, with a mean of 182. 10.7 cm flux was 245, 312, 291, 277, 265, 277 and 225, with a mean of 270. Estimated planetary A indices were 8, 8, 7, 16, 55, 58, and 19, with a mean of 24.4. Middle latitude A Index was 8, 6, 8, 13, 33, 29, and 15, with a mean of 16.


[1] https://nyti.ms/3YiNZtP
[2] https://www.sciencedaily.com/releases/2024/10/241003145438.htm
[3] mailto:k7ra@arrl.net
[4] http://www.arrl.org/propagation
[5] http://arrl.org/propagation-of-rf-signals
[6] http://arrl.org/the-sun-the-earth-the-ionosphere
[7] http://arrl.org/w1aw-bulletins-archive-propagation
[8] http://k9la.us/
[9] https://bit.ly/3Rc8Njt
[10] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS