SB PROP @ ARL $ARLP019
ARLP019 Propagation de K7RA

ZCZC AP19
QST de W1AW
Propagation Forecast Bulletin 19 ARLP019

From Tad Cook, K7RA

Seattle, WA May 12, 2023
To all radio amateurs

SB PROP ARL ARLP019
ARLP019 Propagation de K7RA

We saw a modest increase in solar activity in this reporting week,
May 4-10.

Average daily sunspot numbers nudged up from 114 to 119.3, and
average daily solar flux from 151.5 to 167.1

Average daily planetary A index changed from 13.6 to 15.1, and
average middle latitude A index remained the same, 11.9.

Predicted solar flux is 160 on May 12-13, then 155, 150 and 150 on
May 14-16, 145 on May 17-18, 155 on May 19-21, 150 on May 22, 145 on
May 23-25, then 140 and 145 on May 26-27, 155 on May 29-30, 160 on
May 31 through June 1, 155 on June 2-3, 160 on June 4-7, then 165,
160, 150, 145 and 150 on June 8-12, and 155 on June 13-17.

Predicted planetary A index is 30, 12 and 8 on May 12-14, 5 on May
15-22, then 12 and 20 on May 23-24, 15 on May 25-26, 10 on May
27-28, 8 on May 29, 5 on May 30 through June 1, then 16, 12, 16 and
12 on June 2-5, 8 on June 6-8, and 5 on June 9- 18, then 12 and 20
on June 19-20.

Stormy space weather:

https://www.space.com/sun-reverse-sunspot-auroras-supercharge

BBC on viewing aurora:

https://www.sciencefocus.com/news/northern-lights-may-2023-backward-sunspot/

More:

https://bit.ly/44Rruxk

Jon, N0JK wrote on May 9:

"Good 6 Meter Es, TEP May 7 FT8 from northeast Kansas.

I worked CX2AQ and LU5FF from home with an attic dipole on FT8. This
around 2115 UTC. Not strong, but solid contacts. I then set up
portable.

Worked CE2SV and CE3SX. CE3SX called me, also FT8. Had difficulty
keeping yagi up due to gusty winds. On ON4KST Dale, CE2SV noted:

00:11:46 N0JK Jon, A struggle on my side, wind blew antenna down
several times and broke director. Duct tape to the rescue.

00:11:07 N0JK Jon (CE2SV) Dale - Thank you for the contact.

22:42:46 CE2SV Dale (N0JK) Finally Jon ... TU

Gary, N0KQY observes there is a 'consistent time frame' for Es --
TEP to South America from the Midwest. Best seems to be 2000-0000
UTC."

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere May 12-18, 2023 from F.K. Janda, OK1HH.

"The more vivid and complex solar activity is, the less predictable
it is. The same is valid for its effects in the Earth's
magnetosphere and ionosphere.

This was particularly true of the solar flares of May 4 and 5, and
also of the G2 class geomagnetic storm with auroras. The CMEs
overlapping each other were difficult to separate.

Another CME that struck the Earth on May 7 (1544 UTC) was expected
but, contrary to predictions, did not cause a significant storm.
Another Coronal Mass Ejection (CME) hit the Earth on May 9 at 2310
UTC.

Shortly before, AR3296 (with reversed magnetic polarity and thus
violating Hale's law) released a double solar flare.

The consequence was the Dellinger effect (a shortwave fade) up to 25
MHz from 1900-2100 UTC. Another CME followed with a velocity of over
1,000 km/s (2.24 million mph). Shock waves at its leading edge
accelerated protons to nearly the speed of light, making them
'relativistic particles', for which time passes more slowly. They
can reach the Earth and affect the ionosphere.

These lines are written on the afternoon of 11 May UTC, when the
particles from the eruption of 9 May with a maximum at 1858 UTC are
expected to arrive.

Large AR3296 and AR3297 will set behind the northwestern edge of the
solar disc in a few days. In the meantime, AR3301 and AR3302 emerged
in the northeast.

Helioseismological observations indicate another large sunspot group
will follow them out. Therefore, the current variable nature of the
evolution with numerous disturbances will continue."

Five days ago from Dr. Tamitha Skov:

https://youtu.be/E1lBqqWEa5Q

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 May 4 through 10, 2023 were 139, 90, 99, 99,
103, 151, and 154, with a mean of 119.3. 10.7 cm flux was 162,
161.9, 151.8, 157.2, 171.9, 194.7, and 170.1, with a mean of 167.1.
Estimated planetary A indices were 6, 5, 30, 9, 16, 14, and 26, with
a mean of 15.1. Middle latitude A index was 7, 4, 21, 8, 13, 11, and
19, 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 $ARLP019
ARLP019 Propagation de K7RA

ZCZC AP19
QST de W1AW
Propagation Forecast Bulletin 19 ARLP019

From Tad Cook, K7RA

Seattle, WA May 10, 2024
To all radio amateurs

SB PROP ARL ARLP019
ARLP019 Propagation de K7RA

"ASWFC GEOMAGNETIC DISTURBANCE WARNING ISSUED AT 2302 UTC/09 MAY
2024 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.

"Four halo CMEs first observed over 08-09 May are expected to arrive
at Earth on 10-May, starting at 1000 UTC +/- 10 hours. G4
geomagnetic conditions are expected on 10-May, reducing to G3 with a
chance of G4 on 11-May.

"INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS
EJECTION FROM 10-12 MAY 2024.

"GEOMAGNETIC ACTIVITY FORECAST:

"10 May: G4
11 May: G3, chance of G4
12 May: G1"

Six new sunspot groups appeared this reporting week, May 2-8, one
each day on May 2-4, two on May 5 and another on May 6. On May 9 two
more sunspot groups emerged, and the daily sunspot number rose to
170.

Average daily sunspot number increased from 124.6 to 138.3, and
average daily solar flux rose from 144.9 to 177.6.

Average daily planetary A index climbed from 9.6 to 14.4, while
middle latitude numbers went from 8.6 to 12.3.

The most active day was May 2, when the planetary A index was 44.
Alaska's College A index was 61. The cause was two CMEs striking
Earth, causing a G3 class geomagnetic storm.

The solar flux is peaking now and may peak again around June 11-12
at 205.

Predicted solar flux is 240 and 225 on May 10-11, 220 on May 12-13,
then 215 on May 14, then 210 on May 15-16, and 200, 195, 190, 185,
180, 175, 170, 165 and 170 on May 17-25, then 175 on May 26-27, 170
on May 28, then 165 on May 29-31, then 175, 180, 185, 190 and 185 on
June 1-5, 175 on June 6-9, 180 on June 10, 205 on June 11-12, then
200, 195, 190 and 185 on June 13-16.

Predicted planetary A index is 8, 5, 8, 12 and 10 on May 10-14, 5 on
May 15-22, then 8, 12, 8, 5, 12 and 8 on May 23-28, then 5, 5 and 8
on May 29-31, and 12 on June 1-3, then 8, 10, 5 and 5 on June 4-7,
then 8, 15 and 10 on June 8-10, and 5 on June 11-18.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - May 9, 2024 from OK1HH.

"This week, the number of sunspot groups was smaller than in
previous weeks (decreased from nine on Monday to six on Wednesday),
but two of them (AR3663 and AR3664) are really big. Moreover, both
have a beta-gamma-delta magnetic configuration, indicating the
possibility of producing strong solar flares. Moderate flares
(M-class) were observed several times a day and large flares
(X-class) were not an exception.

"Although AR3663 is now approaching the northwestern limb of the
solar disk, the overall solar activity is certainly not decreasing,
quite the contrary: AR3664 continued to grow rapidly, and has merged
with neighboring AR3668 to rival the large Carrington spot of 1859
in size. If it were to produce a CME eruption similar to 1859, and
if the CME were to hit the Earth, the so-called 'Carrington Event'
could be repeated, with potentially devastating consequences for
power and communications grids.

"So far, on the lower shortwave bands, we have seen rapid and large
increases in attenuation during large flares, up to and including
disruption of communications for tens of minutes to hours. The
phenomenon is abbreviated SWF (Shortwave Fading), belongs to the SID
(Sudden Ionospheric Disturbance) group. SWF is named after two
physicists, John Howard Dellinger and Hans Mogel, as the Dellinger
effect, or sometimes Mogel-Dellinger effect.

"Solar flares with CMEs in the western half of the solar disk appear
to be followed by an increase in geomagnetic activity and a marked
fluctuation in shortwave propagation conditions around the weekend,
with a slow return to average conditions in the following days."

Recent reports from Dr. Tamitha Skov, WX6SWW:

https://www.youtube.com/watch?v=CGdPOsRgBIE

https://www.youtube.com/watch?v=RDEWbYqyNAo


Today's large sunspot comparable to Carrington Event:

https://bit.ly/3Uxd94R


Not like Carrington event:

https://bit.ly/4dA8eJ3


Northern lights:

https://wapo.st/3UyKgp8

https://bit.ly/3JX27kK

https://bit.ly/3JUrbZr


Really big sunspots:

https://bit.ly/44E2gTI


Flare attacks Earth:

https://voi.id/en/technology/379507


May 11 warning on X-Class Solar Flares:

https://bit.ly/4bv45o5


Celestial onslaught of three Solar Flares:

https://bit.ly/4dAPDNk


Solar storm train:

https://bit.ly/3wjypDl


Aurora in Oregon and Washington.

https://bit.ly/4dvKDJE


More on Solar Storms:

https://bit.ly/3JQv3e6

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 May 2 through 8 2024 were 125, 121, 136, 152,
148, 144, and 142 with a mean of 138.3. 10.7 cm flux was 141.9, 156,
166.6, 176.9, 171.2, 203.6, and 227.1, with a mean of 177.6.
Estimated planetary A indices were 44, 10, 6, 12, 15, 7, and 7, with
a mean of 14.4. Middle latitude A index was 24, 16, 5, 12, 13, 6,
and 10, with a mean of 12.3.
NNNN
/EX


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