SB PROP @ ARL $ARLP014
ARLP014 Propagation de K7RA

ZCZC AP14
QST de W1AW
Propagation Forecast Bulletin 14 ARLP014

From Tad Cook, K7RA

Seattle, WA April 7, 2023
To all radio amateurs

SB PROP ARL ARLP014
ARLP014 Propagation de K7RA

Average solar flux and sunspot numbers were way down this week.
Sunspot numbers were down by half, from 112.6 last week to 53.4.
Average daily solar flux declined from 156.1 to 132.5.

Geomagnetic indicators were lower too. Average daily planetary A
index from 23.3 last week to 15 in this bulletin, and average daily
middle latitude A index from 13.7 to 11.7.

The April 1 middle latitude A index of 11 is my guess. The middle
latitude A index for April 1 was not available.

Predicted solar flux is 140 on April 7 and 8, 135 on April 9 to 11,
140, 145 and 130 on on April 12 to 14, 130 on April 14, 135 on April
15 to 17, 140 on April 18 to 20, 135 on April 21 to 23, then 130,
125 and 120 on April 24 to 26, 115 on April 27 to 29, 125 on April
30, 120 on May 1 and 2, 115 on May 3 and 4, then 110 on May 5 to 7,
and 115, 120, 125 and 130 on May 8 to 11, then 135 on May 12 to 14,
and 140 on May 15 to 17.

Predicted planetary A index is 5 on April 7 to 10, then 8, 8 and 5
on April 11 to 13, 8 on April 14 and 15, then 12, 10 and 15 on April
16 to 18, then 5, 20, 15 and 10 on April 19 to 22, 5 on April 23 to
25, then 15 and 18 on April 26 and 27, 15 on April 28 and 29, 8 on
April 30, 10 on May 1 and 2, 8 on May 3, then 5 on May 4 to 6, then
12, 10, 8 and 5 on May 7 to 10, 8 on May 11 and 12, then 10, 12, 15,
5 and 20 on May 13 to 17.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere -- April 6, 2023 from F.K. Janda, OK1HH.

"On March 29, another solar flare of category X1.2 was observed. It
came from the AR3256 sunspot group near the southwestern limb of the
Sun.

This year, in just three months, we've already seen seven X-class
flares, the same as all of last year. There are still about two
years to go before the cycle peak.

On the morning of March 31, a solar wind stream hit Earth,
triggering a minor G1-class geomagnetic storm. A relatively quiet
weekend followed.

Then new sunspot group AR3270 emerged in the southern part of the
solar disk. It grew rapidly, its two dark cores, larger than Earth,
indicating an unstable magnetic field. If they merge an eruption
would likely follow. It would probably be a geoeffective eruption
because the sunspot was directly opposite the Earth.

After the AR3270 sunspot group dips behind the southwestern limb of
the solar disk this weekend, there should be a temporary drop in
overall solar activity, accompanied by a string of geomagnetically
quieter days.

As the irregular occurrence of higher geomagnetic activity results
in irregular changes in shortwave propagation conditions, the
subsequent evolution should be more regular and predictable."

This video from Tamitha Skov came out right after last week's
bulletin:

https://youtu.be/F8ERhLiOK88

More sun fun:

https://youtu.be/VWhhSWjDJtw

https://bit.ly/41aolq2

Don't worry:

https://bit.ly/3zCtg74

On April 5 from 1723 to 1746 UTC, Tom, WA1LBK in Fall River,
Massachusetts copied HC1MD/2 in Ecuador on 6 meter FT8. Check HC1MD
on QRZ.com for some beautiful photos by Rick, NE8Z.

https://bit.ly/3zBm5wa

This weekend is the CW portion of the Japan International DX
Contest.

See http://jidx.org/

Send your tips, reports, observations, questions and comments to
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 http://www.arrl.org/propagation and the ARRL Technical Information
Service 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/ .

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

Sunspot numbers for March 30 through April 5, 2023 were 99, 61, 23,
54, 56, 44, and 37, with a mean of 53.4. 10.7 cm flux was 140.3,
129.3, 125.3, 126.9, 133.6, 135.7, and 136.6, with a mean of 132.5.
Estimated planetary A indices were 17, 21, 13, 15, 15, 13, and 11,
with a mean of 15. Middle latitude A index was 11, 17, 11, 13, 11,
10, and 9, with a mean of 11.7.
NNNN
/EX


--- MBSE BBS v1.0.8 (Linux-x86_64)
* Origin: American Radio Relay League (3:633/280.2@fidonet)

SB PROP ARL ARLP014
ARLP014 Propagation de K7RA

ZCZC AP14
QST de W1AW
Propagation Forecast Bulletin 14 ARLP014

From Tad Cook, K7RA

Seattle, WA April 5, 2024
To all radio amateurs

SB PROP ARL ARLP014
ARLP014 Propagation de K7RA

With the big increase in sunspot numbers and solar flux reported in
last week's Propagation Forecast Bulletin ARLP013, I hoped the trend
would continue, but numbers this week were lower.

Five new sunspot groups emerged, one each day from March 30 through
April 3.

Average daily sunspot numbers went from 147 to 60, and average daily
solar flux declined from 191.9 to 136.9.

Geomagnetic numbers were much quieter. Average daily planetary A
index softened to 7.6 from 25.4.

Predicted solar flux is 115 on April 5-8, 120 on April 9-10, 125 on
April 11, 140 on April 12-13, 150 on April 14-16, 160 on April
17-18, 170 on April 19-24, then 160, 150 and 140 on April 25-27,
then 130 on April 28 through May 4 then 160, 150, and 140 on May
5-10, then 150 on May 11-13.

The predicted flux values this week are much lower than in last
week's forecast for the same period.

Predicted planetary A index is 16 and 10 on April 5-6, 5 on April
7-8, 8 on April 9-10, 5 on April 11-18, 8 and 10 on April 19-20, 8
on April 21-23, 5 on April 24-26, 10 on April 27-28, 8 on April 29,
and 12 on April 30 through May 2, then 8, 5 and 5 on May 3-5, 8 on
May 6-8, and 5 on May 9-15.

The Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - April 4, 2024 from OK1HH.

"The two large and very active sunspot groups, AR3614 and AR3615,
bade us farewell last week by going beyond the western limb of the
solar disk. AR3615 still unleashed two powerful M-class flares and
an X1 flare that ionized the upper part of the Earth's atmosphere
and caused the Dellinger effect (shortwave fade) over the Pacific
Ocean on March 28 (with a maximum at 2053 UTC).

"AR3615 still managed to produce an M9.4-class solar flare on March
30, which was only one percent weaker than an X-class flare. After
that, we expected particles originating from solar radiation to
arrive in the vicinity of Earth, but this did not happen. The
development in the following days was therefore relatively quiet.

"Due to the calming of the geomagnetic field, we expected an
improvement in shortwave propagation. This occurred from 2 April
onwards but was only very slight due to the rapid decrease in solar
activity. After the return of active regions to the solar disk, we
expect an improvement in propagation, especially in the third decade
of April."

(I think he refers to a decade as a ten day period, so this would be
the last ten days of April).

Angel Santana, WP3GW, sent an email about last week's contest:

"WPX for me was pretty good even though I did not reach my goal.
There were openings toward Europe during Saturday midnight on 20
meters.

"Now on Sunday at midday, I noticed a reduction of stations on 10
meters, just like 2 weeks ago, but there were many strong stations
from South America and an hour later back to normal. My friend Jose,
KP4JRS (who operated as NP3YL) noticed this over the two days on 10
meters.

"Also noticed when a big contest is on the air, the bands tend to be
almost 'noiseless.'

"Not sure if because the SFI has gone down but today Thursday at
1500 UTC there is much noise on the bands. Hope the weekend fares
better."

WX2R reminds us that coming up on Monday, April 8 is the HamSCI
Solar Eclipse QSO Party:

"Join with thousands of your fellow amateurs as part of the largest crowd-sourced event for ham radio scientific exploration ever! The
SEQP is part of 'The Festivals of Eclipse Ionospheric Science' and
is for learning more about how the ionosphere works. Use any mode,
any band for all or part of the day!

"Participation can be from everywhere - you need not be near the
path of the eclipse to contribute valuable data by participating.

"Are you a contester? For details on the SEQP contest and rules go
to www.hamsci.org/contest-info. Don't forget to send in your log.

"For the Gladstone Signal Spotting Challenge using CW, WSPR and
FST4W modes, go to www.hamsci.org/contest-info.

"If you're an SWL or AM DX'er, there is the 'Medium Wave Recording
Event' for you as well. Go to www.hamsci.org/mw-recordings/.

"Or just get on the air and help provide the data to better
understand the ionosphere. Monday, 8 April 2024. Get on the air!
1400-2400 UTC.

"Do it for science! Any band/any mode except 60, 30, 17, and 12
meters."

From Forbes Magazine, an eclipse guide:

https://bit.ly/3J4zzoX

A DailyMotion video of a long duration flare, but no date given:

https://www.dailymotion.com/video/x8w8viq

Chip, N2YO, sent this email last week.

"Thanks for your excellent ARRL propagation bulletins!

"I also am running a weekly propagation bulletin for more than 20
years (in Romanian language). The bulletin is available on the web,
distributed online by email, and read during the 'Info DX' QTC on
80m each Thursday in Romania.

"All bulletins are available here:

https://www.radioamator.ro/misc/buletinepropagare.php

"On the first of each month I update a page of propagation charts in
certain directions, centered on YO:

https://www.radioamator.ro/misc/grafice_propagare.php

"I also run a YO DX Cluster which is powered by a DX Spider server
hosted by a Raspberry Pi in my basement that feeds a web page:

"https://www.radioamator.ro/yocluster/

"In fact, I run the whole radioamator.ro website, which is the most
popular YO ham radio resource on internet. This year the website
will have the 20th anniversary."

Recent video from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/yKNB1YRX7kg

Send your tips, reports, observations, questions and comments to
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 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 March 28 through April 3 2024 were 101, 79, 60,
50, 50, 35, and 45, with a mean of 60. 10.7 cm flux was 172.7,
167.3, 139.6, 133.6, 120.4, 112.8, and 111.7, with a mean of 136.9.
Estimated planetary A indices were 7, 6, 5, 9, 11, 8, and 7, with a
mean of 7.6. Middle latitude A index was 6, 4, 4, 8, 9, 7, and 10,
with a mean of 6.9.
NNNN
/EX


--- MBSE BBS v1.0.8.4 (Linux-x86_64)
* Origin: American Radio Relay League (3:633/280.2@fidonet)