SB PROP @ ARL $ARLP037
ARLP037 Propagation de K7RA

ZCZC AP37
QST de W1AW
Propagation Forecast Bulletin 37 ARLP037

From Tad Cook, K7RA

Seattle, WA September 16, 2022
To all radio amateurs

SB PROP ARL ARLP037
ARLP037 Propagation de K7RA

Solar activity bounced back this reporting week, September 8-14,
when average daily sunspot numbers jumped from 68 to 92.7, and
average solar flux from 125.8 to 141.3.

Fewer CMEs and flares were evident, with average planetary A index
declining from 24.6 to 10.7, and middle latitude numbers from 17.4
to 10.6.

New sunspot groups appeared, one on September 8, three on September
10, and one more on September 13. Total sunspot area (in millionths
of a solar disc) on September 12-14 rose from 370 to 870 to 1240,
the highest value in over a month.

The sunspot number was highest on September 10 at 122.

During this week two years ago, there were no sunspots at all, and
average daily solar flux was only 69.7, over 56 points lower than
this week, demonstrating the continued progress of Solar Cycle 25.

The latest (Thursday) forecast from space weather folks at Offut Air
Force Base shows predicted solar flux peaking at 150 on October 9,
but with flux over the next few days following this bulletin less
optimistic than the numbers in the bulletin preview in Thursday's
ARRL Letter.

Predicted flux values on September 16-17 are 140 and 135, then 125
on September 18-19, 120 on September 20-29, 125 on September 30
through October 6, 130 on October 7-8, then 150, 148, 143 and 140 on
October 9-12, then 136, 130, 125 and 120 on October 13-16, 125 on
October 17-18, and 120 on October 19-26.

Predicted planetary A index shows moderate levels of geomagnetic
activity until October 1-2. The forecast is 15, 18 and 10 on
September 16-18, 5 on September 19-23, then 10 on September 24, 14
on September 25-27, 8 on September 28-29, then 22, 50, 30, 20 and 12
on September 30 through October 4, then 15, 12, 10, 8 and 5 on
October 5-9, then 10, 8, 5, 15, 20 and 12 on October 10-15, then 5
on October 16-19, then 12 and 10 on October 20-21, and 14 on October
22-24.

The Autumnal Equinox is only a week away!

Nice solar video from last month:

https://bit.ly/3BH9ZDm

Here is NOAA's latest forecast discussion:

https://www.swpc.noaa.gov/products/forecast-discussion

Comments from F.K. Janda, OK1HH:

"Although the Sun was speckled a week ago, all areas were quiet and
overall, the Sun's activity was low. After that, activity began to
grow rapidly in the northern hemisphere.

"Sunspot group AR3098 grew larger and on September 11, a C6 class
flare was registered. The old area AR3088, which was active during
the last rotation of the Sun, returned in the southeast solar limb.

"Two solar wind shock waves hit our planet on September 14 at 0630
UTC and 2313 UTC. The second of them significantly expanded the
speed of the solar wind, started a disturbance of the Earth's
magnetic field and caused very uneven shortwave propagation
conditions, especially on routes leading through higher latitudes.
Auroral distortion of signals were observed when passing through inhomogeneities in the auroral belt.

"Further similar disturbances can be expected on September 17th, a
calm after September 18th and a decrease in solar activity is
expected after September 20th."

The following is edited from an email from David Greer, N4KZ in
Frankfort, Kentucky:

"With the Sun perking up from its long sleep, one of my favorite
bands, 12 meters, is also coming alive. I've worked FT8 DX on 12
meters from time to time for months, but things really came alive
for me from 1236-1356 UTC on September 14 when I worked 22 DX
stations back-to-back on SSB.

"I called CQ and was answered by a Dutch station and after that,
stations just kept calling and calling. I put 22 DX stations in my
log. Most were from Europe, but I also worked the Middle East and
Northwest Africa, 18 different DX entities all together.

"Some signals were quite strong, mostly because they ran high power
with beam antennas but one station was thrilled to make the trip
across the pond from Europe because, he said, 'he was running 100
watts to an indoor dipole in his apartment.'

"Some commented it was their first ever 12-meter QSO. I hear that
often from stations everywhere. Some say they didn't think anyone
ever used 12 meters. Since 2000, I have 12 meter WAS and confirmed
182 DX entities on 12 alone.

"I often call CQ on SSB when the band seems dead, only to have a
rare DX station respond, such as VP8LP in the Falkland Islands.

"I was on 12-meter SSB the first night hams in the USA were
authorized to use the band in 1985. That night, the band was wild
because of a big sporadic-E opening and strong signals were coming
from all directions across North America. It was a blast!

"I am fortunate to have a decent station -- 8-element log periodic
antenna up 50 feet from a hilltop QTH with a kilowatt amp. But many
signals were so strong on September 14 that I am sure others with
modest stations could work many DX stations. I had to QRT at 1356
UTC even though others were still calling. I got back on the band
later in the day and worked MW0ZZK in Wales. He was 20 over S9.

"Don't forget about 12 meters. When 10 meters is open, 12 is open
too. And don't forget about the phone band allocation, which starts
at 24.930 MHz in the USA. I've heard some out of band because they
didn't know where the band edge was.

"A great propagation tool is the MUF web page operated by KC2G at https://prop.kc2g.com/ . I monitor it constantly. It tells me what
bands to check out and where I should aim my antenna. Plus, it has
other interesting data in the menu."

Thanks to Dave for mentioning that great web site. I notice it has a
section labeled eSSN, which is Effective Sunspot Number, derived
from 10.7 cm solar flux. More about eSSN from NorthWest Research
Associates, based here in the Seattle area:

https://spawx.nwra.com/spawx/ssne24.html

Also, I would like to add that often 12 meters is open when 10
meters seems dead.

Here is more crazy solar news:

https://bit.ly/3QIrXKd

Here is Newsweek again:

https://bit.ly/3UhnuAS

Some solar wind news:

https://bit.ly/3BLjh1i

Lucky us! A brand new video, dated today, from Dr. Tamitha Skov,
WX6SWW:

https://youtu.be/OAOmI-3YxUA

Send your tips, reports, observations, questions, and comments to k7ra@arrl.net.

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 September 8 through 14, 2022 were 75, 72, 122,
113, 117, 93, and 57, with a mean of 92.7. 10.7 cm flux was 126.6,
126.2, 135.9, 151.5, 150.4, 154.1, and 144.3, with a mean of 141.3.
Estimated planetary A indices were 19, 13, 12, 9, 9, 4, and 9, with
a mean of 10.7. Middle latitude A index was 17, 14, 10, 9, 9, 5, and
10, with a mean of 10.6.
NNNN
/EX


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

SB PROP @ ARL $ARLP037
ARLP037 Propagation de K7RA

ZCZC AP37
QST de W1AW
Propagation Forecast Bulletin 37 ARLP037

From Tad Cook, K7RA

Seattle, WA September 15, 2023
To all radio amateurs

SB PROP ARL ARLP037
ARLP037 Propagation de K7RA

Like last week, eight new sunspot groups emerged this reporting
week, September 7-13.

One appeared on September 7, another September 9, four more on
September 10, another on September 11 and one more on September 12.

Solar activity made a nice comeback, with average daily sunspot
numbers rising from 95.4 to 138.1, and solar flux from 137.6 to
159.9.

The most active geomagnetic day was September 12, when the planetary
A index was 25. Spaceweather.com reported a "stealth CME"
(unexpected) that had aurora visible down as far as Missouri.

Average daily planetary A index decreased from 15.4 to 10.4, and
middle latitude numbers from 16.3 to 11.3.

The Autumnal Equinox in the Northern Hemisphere is just a week away,
on September 22.

It seems that the next sustained short term peak in solar flux is a
few weeks off, with values between 150 and 155 over October 12-17,
although it is expected to reach 150 on September 23-24.

The forecast shows solar flux at 145, 148, 145 and 145 on September
15-18, 140 on September 19-21, 145 on September 22, 150 on September
23-24, 145 on September 25, 140 on September 26-27, 135 on September
28-30, then 130, 135, 130 and 135 on October 1-4, 140 on October
5-6, 135 on October 7-8, 140 on October 9, 145 on October 10-11, 150
om October 12-13, then 155, 150, 155 and 150 on October 14-17, 145
on October 18-19, and 150 on October 20-21.

Predicted planetary A index is 15 on September 15, 8 on September
16-17, then 5, 5, and 10 on September 18-20, 5, 8 and 12 on
September 21-23, 5 on September 24-27, then 8, 12 and 8 on September
28-30, and 5 on October 1-8, then 15, 12, 10 and 8 on October 9-12,
5 on October 13-19, 12 on October 20, and 5 on October 21-24.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - September 15-22, 2023 from OK1HH.

"A week ago, the active sunspot group AR3414 dominated the solar
disk. It is now on the far side of the Sun. This role has been taken
over by AR3423, now approaching the western limb of the solar disk.
It will be followed the next day by the slightly smaller AR3425. The
important information is that we observe a coronal hole near both of
them (closer to AR3425). This configuration was the likely cause of
the surprise: Few people expected the Earth to be hit by a CME on
September 12 at 1237 UT.

"Then a massive disturbance of the Earth's magnetic field developed.
Its initial positive phase increased the MUF values on September 12.
This was followed by a negative phase, which in turn caused a
significant decrease in MUF, with worsened shortwave propagation
conditions on 13 September. This was followed by a gradual
improvement on 14 September, when the magnetic filament connecting
sunspots AR3423 and AR3425 erupted. The consequence could be a G1 to
G2 class geomagnetic storm in the Earth's vicinity on 17 September."

Jon Jones, N0JK wrote from Kansas:

"Sunday afternoon and evening (September 10-11) strong sporadic-E on
6 meters took place.

"This set up links to TEP on to South America.

"The hot spot seemed to be south Central Kansas and northeast
Oklahoma. KF0M in EM17 worked many South American stations. From
EM28, the Es was not lined up that well.

"Had many strong stations in south Texas and northern Mexico.
Around 2250 UTC LU1MQF (FF55) and CE4MBH (FF44) appeared for a few
minutes on 50.313 MHz FT8.

"Any sporadic-E is a treat in the September ARRL VHF contest (which
was last weekend). With Solar Cycle 25 picking up, the Es can link
to TEP."

An article about the Sun from IFLScience:

https://www.iflscience.com/has-part-of-the-sun-really-become-broken-70653

The latest from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/S2IOBwSo_LI

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.

Also, check this article from September, 2002 QST:

https://bit.ly/3Rc8Njt

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 September 7 through 13, 2023 were 135, 123, 119,
167, 173, 141, and 109, with a mean of 138.1. 10.7 cm flux was
160.8, 160.9, 161.4, 163.9, 176.4, 153.5, and 142.6, with a mean of
159.9. Estimated planetary A indices were 6, 6, 8, 4, 7, 25, and 17,
with a mean of 10.4. Middle latitude A index was 11, 8, 12, 6, 8,
17, and 17, with a mean of 11.3.
NNNN
/EX


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