SB PROP @ ARL $ARLP018
ARLP018 Propagation de K7RA

ZCZC AP18
QST de W1AW
Propagation Forecast Bulletin 18 ARLP018

From Tad Cook, K7RA

Seattle, WA May 5, 2023
To all radio amateurs

SB PROP ARL ARLP018
ARLP018 Propagation de K7RA

Spaceweather.com posted the following report on May 4:

"REVERSED-POLARITY SUNSPOT EXPLODES: A rare reversed-polarity
sunspot exploded today, producing a long-lasting M-class solar flare
and a CME that might hit Earth. Geomagnetic storms are possible this
weekend if/when the CME arrives."

Sunspot activity and solar flux increased over the past reporting
week, April 27 through May 3.

Average daily sunspot numbers climbed from 91.4 to 114, while
average daily solar flux grew from 139.4 to 151.5.

Average daily planetary A index dropped from 26.9 to 13.6, and
average daily middle latitude A index declined from 15.6 to 11.9.

Predicted solar flux over the next month is 162 on May 5-6, 164 on
May 7, 162 on May 8-9, 164 on May 10-11, 170 on May 12-13, then 165,
160, 155, 150, 145 and 140 on May 14-19, 135 on May 20-21, then 130
and 125 on May 22-23, 120 on May 24-25, then 125, 130 and 135 on May
26-28, 140 on May 29 through June 2, then 145, 150 and 155, 160 and
165 on June 3-7, 170 on June 8-9, then 165, 160, 155, 150, and 145
on June 10-14. .

Predicted planetary A index is 5 on May 5, then 12, 8, 5 and 5 on
May 6-9, 5 on May 10-11, 8 on May 12, 5 on May 13-22, 12 and 20 on
May 23-24, 15 on May 25-26, 8 and 12 on May 27-28, 10 on May 29-30,
then 8, 5, 12 and 10 on May 31 through June 3, 5 on June 4-6, 8 on
June 7-8, and 5 on June 9 through mid-month and beyond.

On Wednesday, May 3 Spaceweather.com posted, "INTENSIFYING SOLAR
ACTIVITY: Sunspot complex AR3293-3296 is crackling with strong
M-class solar flares--six of them today so far."

It looks like we face continued favorable HF propagation.

Recently I wrote of my bafflement at 10 meter propagation I observed
using FT8 and pskreporter.info, in which my signals were only being
reported in Florida. I now have a better understanding of this.

On May 1 from 1930-2030 UTC I saw the same thing, with reports from
2,200-2,700 miles away, which suggests a 500 mile wide skip
distance. Mexican stations also reported me, over that same distance
in a 500 mile band. So, this suggests that it isn't just Florida,
and that the same signal is stretching out into the Gulf of Mexico
and the Atlantic Ocean, but I don't see it because there are no
stations there to receive my signal.

Later I saw multi-hop reports from ZL4KYH at 7,246 miles, 5W1SA at
5,230 miles, LU8EX at 6,893 miles and LU4FTA at 6,750 miles.

Jon N0JK wrote on April 29:

"I was able to work LU9DO, LU8EX and PY2XB that afternoon. The South
American signals popped up on what was otherwise a dead band. Later
some station in Florida came in. I was running 50 watts and a 3
element Yagi portable in EM28, northeast Kansas. May 1 - D2UY worked
stations in Florida and W3LPL in Maryland on was likely Es -- TEP.

"There will likely be more of these Es -- TEP openings in early
May."

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere May 05-11, 2023 from OK1HH:

"While long-term forecasters are beginning to come to terms with the possibility that the growth in solar activity could slow this year
and the current 25th cycle may not be one of the high ones, solar
activity has begun to increase. Already last week, sunspot group
AR3288 in the southwest with an unstable delta class magnetic field
was the source of an M7 class solar flare on May 1 at 1309 UTC. But
another M7 class eruption occurred on May 3 in the newly emerged
AR3293 in the northeastern part of the solar disk.

"Interestingly, a new group of spots, AR3296 in the northwest,
violates Hale's Law, as it has the opposite magnetic polarity that
is appropriate in the current 11-year cycle (polarity should be
negative on the left and positive on the right).

"The solar wind speed and Earth's magnetic field activity have
finally begun to decrease after a long active period, and the
conditions for shortwave propagation have finally improved, although
not to the extent we had hoped."

A story from Sky & Telescope about the Sun:

https://bit.ly/3NGlMbp

Two stories about massive solar flares, one from about 400 years
ago:

https://bit.ly/427oI5w

https://bit.ly/3ASEfu1

Some nonsense about flares:

https://bit.ly/3NGD5t3

More Aurora in our future:

https://bit.ly/3AZxDKl

A story about Radio Blackout:

https://bit.ly/41bVL74

More about Aurora Australis:

https://ab.co/44qDbet

This weekend is the 10-10 CW QSO Party, on 10 meters of course:

https://www.ten-ten.org/activity/2013-07-22-20-26-48/qso-party-rules

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 April 27 through May 3, 2023 were 136, 111, 82,
105, 87, 134, and 143, with a mean of 114. 10.7 cm flux was 140.8,
149.8, 155.8, 153.5, 147.9, 156.8, and 156.2, with a mean of 151.5.
Estimated planetary A indices were 23, 19, 20, 10, 10, 9, and 4,
with a mean of 13.6. Middle latitude A index was 20, 16, 18, 8, 8,
9, and 4, with a mean of 11.9.
NNNN
/EX


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

SB PROP @ ARL $ARLP018
ARLP018 Propagation de K7RA

ZCZC AP18
QST de W1AW
Propagation Forecast Bulletin 18 ARLP018

From Tad Cook, K7RA

Seattle, WA May 3, 2024
To all radio amateurs

SB PROP ARL ARLP018
ARLP018 Propagation de K7RA

"ASWFC GEOMAGNETIC DISTURBANCE WARNING ISSUED 1817 UTC/02 MAY 2024
BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.

"A period of planetary G3 geomagnetic conditions has been observed
on 02-May, associated with two recent CME arrivals and a sustained
period of southward IMF conditions. Further periods of G3 are
possible over 02-03 May.

"INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS
EJECTION FROM 02-03 MAY 2024.

"GEOMAGNETIC ACTIVITY FORECAST:
02 May: G2-G3
03 May: G2, chance G3, declining to G1"

After the record sunspot numbers reported in last week's Propagation
Forecast Bulletin ARLP017, the April 25 through May 1 reporting week
has more modest numbers. In fact, the average daily sunspot number
(124.6) is less than half the value (265.9) in the previous
bulletin.

Seven new sunspot groups appeared this week.

One new sunspot group emerged on April 25, another on April 27, two
more on April 29 and one each on April 30 and May 1.

Average daily solar flux shifted from 216 to 144.9.

Average daily planetary A index dropped from 13.9 to 9.6.

The solar flux estimate for the next month has values peaking at 205
on May 15-16 and again on June 11-12.

The values are 135 on May 3, 132 on May 4-5, then 134 and 136 on May
6-7, 138 on May 8-9, then 140, 155, 160, 175 and 180 on May 10-14,
205 on May 15-16, then 200, 195, 190, 185, 180, and 165 on May
17-22, 145 on May 23-24, then 140, 135, 130, and 125 on May 25-28,
then 120, 115 and 120 May 29-31, 125 on June 1-2, 130, 145, and 150
June 3-5, 155 on June 6-7, then 160, 175 and 180 on June 8-10, and
205 on June 11-12.

Predicted planetary A index is 18, 20, 18 and 10 on May 3-6, 5 on
May 7-22, 15 on May 23, 12 on May 24-25, then 10, 8, 15, 18 and 10
on May 26-30, then 8 on May 31 through June 3, and 5 on June 4
through the middle of the month.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - May 2, 2024 from OK1HH.

"The number of sunspot groups at the present stage of the 11-year
cycle varies between five and twelve. Of these, one to three can be
described as active regions, whereby their size and magnetic
configuration suggest the possibility of energetic flares of
intermediate magnitude. A number of these are accompanied by CMEs,
which, given their position on the Sun, are expected to strike the
Earth. Therefore, predictions of increased geomagnetic activity are
quite often made, but most of them do not come true. Conversely, if
the Earth is affected, a geomagnetic disturbance so strong that it
affects the conditions for shortwave propagation will develop.

"CME collisions with the Earth have mainly caused magnetic storms
and subsequent deterioration of shortwave propagation on 21-22 April
and 27-28 April. Especially in the latter case, the recovery from
the disturbance was very slow, even multi-day, due in part to the
decrease in solar radiation. Added to this was another geomagnetic
disturbance in the late evening hours UTC on 30 April, which caused
a decrease in MUF and a worsening on 1 May."

NOAA article about Solar Cycle 25 progress:

https://bit.ly/3WshU2e

In an email Thursday morning, Dr. Tamitha Skov, WX6SWW, wrote:

"Region 3654 sure has been a point of contention this week. Despite
a lot of big flares, the eruptions that have occurred have been
rather unspectacular-- or so we all thought. Twice now, we have had
stealthy solar storms hit Earth. The first one that hit yesterday,
was not particularly impactful. In fact, for those who have been
following the news in our community chat here on Patreon, you have
seen me discuss the event there, instead of posting an official
'Snapshot.' I did this because that storm was weak and slow, without
much southward-pointing field. In other words, it was so
yawn-worthy, I haven't bothered to update my twitter feed with the
news.

"That all changed when yet another stealthy solar storm hit, just a
few hours ago. This one is much stronger. The top solar disk image
shows the source region for this event. It was an unimpressive event
in coronagraphs, with no clear Earthward directed signature.
However, it has a strong magnetic field, that is pointing southward,
and is fast. This one has given us G3-levels momentarily, but could
keep us at sustained G2-level conditions.

"Both of these events have eluded detection by several (if not all
of the big space weather forecasting agencies) so it is clear,
stealthy solar storms continue to be a problem through solar
maximum. I had been working on a formal forecast, but I am thinking
I will do an impromptu live forecast today since things are
unfolding faster than I can update my current work. Stay tuned. I
will likely go live this afternoon (PDT time), a few hours from now.
Till then, know that we could very easily hit G2-levels within the
next hour at SWPC, if conditions remain as they are."

From Universe Magazine, another Radio Blackout:

https://bit.ly/4bkCHsL

There was another blackout on Thursday, when two CMEs caused a G3
geomagnetic storm. According to Spaceweather.com, another CME is
expected on May 4.

From NDTV, an earlier disturbance:

https://bit.ly/3UpNF9J

From reader David Moore, an article on a fluffy corona:

https://bit.ly/3w9B3eP

From The Daily Galaxy, Solar fury:

https://bit.ly/3UFE6Vg

Cosmic rarity, But did they really need to reference astrology?

https://bit.ly/3wiEaAX

From Space.com, more on Radio Blackouts:

https://bit.ly/3UIWyfW

Another from Space.com about the Solar max:

https://bit.ly/3wjtr9o

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 April 25 through May 1 2024 were 196, 154, 126,
119, 88, 85, and 104 with a mean of 124.6. 10.7 cm flux was 166.7,
152.6, 152.6, 140.1, 137.6, 130.2, and 134.8, with a mean of 144.9.
Estimated planetary A indices were 3, 19, 12, 7, 6, 12, and 8, with
a mean of 9.6. Middle latitude A index was 3, 11, 12, 7, 7, 10, and
10, with a mean of 8.6.
NNNN
/EX


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