02/20/2026

Solar activity returned to low levels this past week. The strongest
event of the period was a C1.8 flare on February 17 from region
4374. This region was also responsible for a C1.4 flare on February
18. The only other flare of note was a C1.1 flare on February 17
from an unnumbered plage region near S05E85. (A plage region is a
bright, intensely hot region in the Sun's chromosphere, typically
found in active areas surrounding sunspots.)

Region 4374 exhibited minor decay through the dissipation of its
trailing spots. Regions 4375 and 4377 were largely unchanged in area
and complexity.
ÿ
A large filament eruption beyond the southwest limb was seen in SDO
and SUVI imagery starting approximately February 18. It was
associated with a Type II radio sweep that began on February 18 with
an estimated shock velocity of 310 km/s. The eruption was first
visible in coronagraph imagery on February 18, but initial analysis
indicates no Earth-directed component. Solar activity is forecast to
be at low levels, with a slight chance for M-class
(R1-R2/minor-moderate) flares through February 20.
ÿ
Solar wind parameters continued to reflect the waning influence of a
positive polarity Coronal Hole High-Speed Stream (CH HSS). Solar
wind speed followed a general declining trend, decreasing from an
initial peak near 600 km/s to approximately 500 km/s by the end of
the reporting period. The solar wind environment is expected to
remain enhanced through February 20 due to continued but weakening
CH HSS influences.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere, February 19, 2026, by F. K. Janda, OK1HH:

"Overall solar activity was relatively high in the first week of
February, with the number of sunspot groups on the solar disk
ranging from seven to nine. Over the next ten days, we observed an
almost uninterrupted decline, at the end of which there were only
three sunspot groups remaining on the disk.

"Significant eruptions could only occur in one of them: AR 4374.
Before it set behind the western limb of the solar disk, one of the
few more powerful eruptions was observed in it. It happened on
February 16, with the peak at 0436 UT, accompanied by a CME,
partially heading towards Earth. The arrival was expected on
February 19. Although it did so at 1501 UT, Earth only encountered
the edge of the particle cloud - and in fact, almost nothing
happened.

"Geomagnetic activity was elevated on February 15-16. The phenomenon
began with a positive phase of disturbance in the evening hours,
during which there was a noticeable improvement in shortwave
propagation conditions. A significant deterioration naturally
followed on February 16, partially also on February 17.

"Any geomagnetic disturbance at the beginning of the predicted
period should be short (on 19th), while another disturbance can be
expected around February 24. Given that solar activity will be on
the rise again at that time, a positive phase of the disturbance can
be expected."

Geomagnetic field activity is expected to be at unsettled to active
levels on February 24 and 25, and on March 5 to 7 due to recurrent
negative polarity CH HSS effects. Active conditions are likely on
March 12 following a solar sector boundary crossing, then again on
March 14 with the onset of a positive polarity CH HSS.ÿ Barring the
potential for CME activity, mostly quiet to unsettled levels are
expected until February 23, and then February 26 to March 4.

The Predicted Planetary A Index for February 21 to 27 is 5, 5, 8,
20, 20, 8, and 5, with a mean of 10.1.ÿ The Predicted Planetary K
Index is 2, 2, 3, 5, 5, 3, and 2, with a mean of 3.1.
10.7-centimeter flux is 105, 120, 130, 135, 130, 130, and 140, with
a mean of 127.1.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[1] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[2]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[3] . Information and
tutorials on propagation can be found at, http://k9la.us/[4] .

Also, check this:

https://bit.ly/3Rc8Njt[5]

"Understanding Solar Indices" from September 2002 QST.

ÿ


[1] http://www.arrl.org/propagation
[2] http://arrl.org/propagation-of-rf-signals
[3] http://arrl.org/the-sun-the-earth-the-ionosphere
[4] http://k9la.us/
[5] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

02/27/2026

Spaceweather.com[1] for February 27 reports about a minor CME hurling
towards Earth.

Solar activity remains at low levels due primarily to C-class flares
just beyond the SE limb near S21. The largest was a C5.3 flare on
February 25. On the visible disk, an approximate 5-degree filament
eruption was observed centered near S08W27 with an associated C2.6
flare.

The eruption was accompanied by a Type II radio sweep (595 km/s) and
possibly two related coronal mass ejections (CMEs), first observed
in ST A COR2 imagery beginning on February 25. Two CMEs were
observed off the NE and E limbs in the imagery. However, SOHO/LASCO
C2 imagery only showed the northerly CME. Analysis of the CMEs is in
progress.
ÿ
Solar activity is likely to remain at low levels with a slight
chance for isolated M-class activity (R1-R2/minor-moderate), as the
bright regions currently seen at the east limb rotate onto the
visible disk.
ÿ
Solar wind parameters continued to show Coronal Hole High Speed
Stream (CH HSS) influence. Solar wind speed ranged from 530-650
km/s. Conditions are likely to return to nominal levels as High
Speed Stream activity wanes.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere, February 26, 2026, by F. K. Janda, OK1HH:

"Between February 22 and 24, there was not a single spot on the
solar disk, which last happened less than four years ago. The
maximum of the 25th cycle is behind us, while the years 2024-2025
can be considered the years of cycle maximum.

"At the same time, the Sun is in a key phase of reversing its
magnetic field. This process is a natural part of the 11-year solar
cycle, usually occurring asymmetrically (the northern and southern
hemispheres of the Sun may reverse at slightly different times, with
the process taking several months). The magnetic field in the polar
regions of the Sun gradually weakens until it completely breaks down
and reforms with the opposite polarity.

"The next eleven-year solar minimum (the transition between the
current 25th and future 26th cycles) is expected in 2030-2031, when
the Sun's magnetic field will stabilize again and the star will
enter a quiet period. A more precise date for the minimum will only
be possible to determine at the end of the decade based on the
current development of sunspots.

"During the first week of March, solar activity should gradually
increase and then decrease in the following week. Changes in the
intensity of the solar wind will have the greatest impact on the
development of shortwave propagation conditions. For prediction of
these changes, it is recommended to monitor the position and area of
coronal holes and, in particular, solar flares that will be located
near their edges.

"This can be monitored excellently at https://www.solarham.com/[2], for example, and even professionals will confirm that you will find
everything you need here to understand the causes of ongoing events
and for operational practice. In addition, we can monitor the local
effects in the ionosphere in detail especially thanks to ionospheric
digisonde stations, dozens of which are available on the internet!"

Active periods are likely, with a chance for G1 (Minor) storm
levels, on February 28 to March 1, due to the anticipated arrival of
a CME that left the Sun on February 25.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to reach high levels on March 3, and then on March 6 to 8
due to anticipated influence of multiple recurrent coronal holes.

The latest report from Dr. Tamitha Skov, WX6SWW, can be found on
YouTube at, https://www.youtube.com/watch?v=6SoYfTnrudc[3] .

The Predicted Planetary A Index for February 28 to March 6 is 5, 5,
5, 5, 5, 15, and 15, with a mean of 7.9.ÿ Predicted Planetary K
Index is 2, 2, 2, 2, 2, 4, and 4, with a mean of 2.6.
10.7-centimeter flux is 122, 122, 125, 125, 125, 125, and 130, with
a mean of 124.9.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[4] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[5]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[6] . Information and
tutorials on propagation can be found at, http://k9la.us/[7] .

Also, check this:

https://bit.ly/3Rc8Njt[8]

"Understanding Solar Indices" from September 2002 QST.

ÿ


[1] http://Spaceweather.com
[2] https://www.solarham.com/
[3] https://www.youtube.com/watch?v=6SoYfTnrudc
[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://k9la.us/
[8] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

03/06/2026

Solar activity continued at low levels with isolated C-class
flaring. Regions 4381 and 4384 remained the primary drivers of
activity. The largest event of the period was a C2.9 flare from
Region 4381 on March 3. Region 4384 continues to rotate further onto
the disk, but foreshortening still hinders a definitive
characterization of its magnetic complexity. Region 4378 showed some
new flux emergence but remained mostly inactive.
ÿ
Region 4383 simplified into a unipolar group following the loss of
its trailing spots, while Region 4380 decayed to plage. No
Earth-directed coronal mass ejections (CMEs) were observed in
available coronagraph imagery.
ÿ
Solar activity is expected to be at low levels, with a chance for
isolated M-class activity (R1-R2/minor-moderate) through March 6.

A brief description of Sunspots can be found on the Space Weather
Prediction Center website at, https://www.swpc.noaa.gov/phenomena/sunspotssolar-cycle[1] .
ÿ
Solar wind parameters reflected the onset of a positive polarity
coronal hole high-speed stream (+CH HSS). Solar wind speed increased
to 450 km/s. Solar wind parameters are expected to remain enhanced
due to the ongoing influence of the +CH HSS. Residual enhancements
are likely to persist, keeping conditions slightly above background
levels before another enhancement is expected with the onset of a
negative polarity coronal hole high-speed stream (-CH HSS).ÿ Active
conditions are expected on March 7 and 8 as high-speed stream
influences continue.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere, March 5, 2026, by F. K. Janda, OK1HH:

"Overall solar activity declined, with the number of sunspot groups
ranging between three and six over the past week. Their magnetic
configuration was simple, so no significant flares on the solar disk
was observed.

"However, the solar flux remained at a relatively high level of
130-148 s.f.u., which, together with a decrease in geomagnetic
activity (no major disturbances, just alternating calm and
moderately active days), resulted in improved conditions for
shortwave propagation.

"The current trend is expected to continue for the time being. A
change will be caused by a decline in solar activity in the second
decade of March. This will be very noticeable in the decline in
solar radio flux."

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to reach high levels on March 8, 11 and 12, and March 15 to
19 due to anticipated influence from multiple, recurrent, CH HSSs.
The remainder of the outlook period is likely to be at normal to
moderate levels.

Geomagnetic field activity is expected to range from quiet to G2
(Moderate) geomagnetic storm levels. Active conditions are likely on
March 10, 12, March 14 and 15, and March 20.ÿ Unsettled conditions
are likely on March 8 and 9, March 11, March 13, and March 16 to 19.
All elevated levels of geomagnetic activity are associated with the
anticipated influence of multiple, recurrent, CH HSSs. The remainder
of the outlook period is likely to be at mostly quiet levels.

The current solar report from Dr. Tamitha Skov, WX6SWW, can be found
on YouTube at, https://www.youtube.com/watch?v=6SoYfTnrudc[2] .

The Predicted Planetary A Index for March 7 to 13 is 5, 8, 10, 18,
10, 15, and 10, with a mean of 10.9.ÿ Predicted Planetary K Index is
2, 3, 3, 4, 3, 4, and 3, with a mean of 3.1.ÿ 10.7-centimeter flux
is 156, 156, 150, 145, 140, 135, and 128, with a mean of 144.3.

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] . Information and
tutorials on propagation can be found at, http://k9la.us/[6] .

Also, check this:

https://bit.ly/3Rc8Njt[7]

"Understanding Solar Indices" from September 2002 QST.

ÿ


[1] https://www.swpc.noaa.gov/phenomena/sunspotssolar-cycle
[2] https://www.youtube.com/watch?v=6SoYfTnrudc
[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://k9la.us/
[7] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

03/13/2026

Solar activity was very low to low. Only low-level C-class activity
was observed from Regions 4384 and 4389. Slight growth was observed
in Regions 4384 and 4391. New Region 4392 was numbered. The rest of
the spot groups were either stable or in decay. No Earth-directed
CMEs were observed. Solar activity is expected to be at low levels,
with a slight chance for M-class (R1-R2/minor-moderate) flares,
through March 14.
ÿ
Solar wind parameters were enhanced through March 11. Solar wind
speed ranged from approximately 480 to 570 km/s during this time but
decreased to around 400-460 km/s through the rest of the period.
ÿ
High Speed Stream activity persists through March 14.

Elevated probabilities are related to the flare potential of both
currently observed spot groups as well as the potential from
returning regions.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at high levels March 16 to 19, and then on March 23
to 30 due to the influence from multiple, recurrent, Coronal Hole
High Speed Streams. The remainder of the outlook period is likely to
be at normal to moderate levels.

Geomagnetic field activity is expected to reach G1 (Minor)
geomagnetic storm levels on March 14, 22, and 25 during the onset of
a CH HSS. G2 (Moderate) geomagnetic storm levels are likely on March
21 due to negative polarity CH HSS effects. Unsettled to active
levels are likely on March 15 to 20, 23 and 24, and on March 256 to
28. All elevated levels of geomagnetic activity are associated with
the anticipated influence of multiple, recurrent, CH HSSs. The
remainder of the outlook period is likely to be at mostly quiet
levels.

The latest solar report from Dr. Tamitha Skov, WX6SWW, can be found
on YouTube at, https://www.youtube.com/watch?v=c9gloRUmKAI[1] .

The Predicted Planetary A Index for March 14 to 20 is 20, 15, 10,
10, 10, 12, and 15, with a mean of 13.1.ÿ The Predicted Planetary K
Index is 5, 4, 3, 3, 3, 4, and 4, with a mean of 4.1.ÿ 10.7
centimeter flux is 110, 110, 110, 110, 110, 105, and 110, with a
mean of 109.3.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[2] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[3]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[4] . Information and
tutorials on propagation can be found at, http://k9la.us/[5] .

Also, check this:

https://bit.ly/3Rc8Njt[6]

"Understanding Solar Indices" from September 2002 QST.
NNNN

ÿ


[1] https://www.youtube.com/watch?v=c9gloRUmKAI
[2] http://www.arrl.org/propagation
[3] http://arrl.org/propagation-of-rf-signals
[4] http://arrl.org/the-sun-the-earth-the-ionosphere
[5] http://k9la.us/
[6] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

04/03/2026

Solar activity has been at low levels with only C-class flares
produced by Regions 4401, 4405, and 4409. There were 9 numbered
active regions on the solar disk, with 4409 showing the most
significant growth during the period and producing the largest flares
on April 1. A new region emerged but it has not yet been numbered.
ÿ
Multiple filaments erupted during the day on April 1, producing
coronal mass ejections (CMEs) observed in coronagraph imagery, but
their propagation modeling did not suggest impacts to Earth. The
exceptions are the ejecta first observed at GONG H-alpha images on
April 1.
ÿ
Solar activity is likely to reach moderate (R1/R2-minor/moderate)
levels, with a slight chance for X-class (R3-strong) flares through
April 4, due primarily to the flare potential of Regions 4404, 4405
and 4409.
ÿ
Solar wind parameters were near nominal levels with solar wind speed
averaging around 440 km/s.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere,ÿ April 2, 2026, by F. K. Janda, OK1HH:

The increase in overall solar activity during the third ten-day
period of March-albeit with a slight delay-led to a gradual rise in
MUF values, extending into the first days of April. An increase in
solar flare activity did not occur until April 30, beginning with a
flare at 0319 UT with an X-ray intensity of X1.4, which lasted a long
time and was accompanied by a CME. Since a large coronal hole No. 36
was located nearby, a significant increase in geomagnetic activity
was expected. This did not occur until April 2, but already during
several preceding active intervals, we could observe the effects of electromagnetic wave scattering on ionospheric inhomogeneities,
clearly visible even on ionograms.

Active region NOAA 4405, located 27 degrees south of the solar
equator, has been clearly visible for a week as the largest on the
solar disk and appears to be stable. On April 3, it passes the
central meridian, and its proximity to coronal hole No. 36 is a
potential source of intensified solar wind. It also indicates higher geomagnetic activity (at G2 level since April 2). This proximity will
likely be the cause of increased geomagnetic activity during the
first ten days of April. Consequently, this will lead to irregular
shortwave propagation conditions and more frequent drops in the MUF.

The next increase in solar activity will likely occur in the last
third of April. Daily MUF values will rise again, and at the same
time, a sporadic E layer will begin to appear occasionally in
mid-latitudes. Although it will not yet have a significant impact on
shortwave propagation, it will occasionally cause interesting DX
openings on the shortest shortwave bands.

The Predicted Planetary A Index for April 4 to April 10 is 22, 10,
15, 8, 7, 25, and 40 with a mean of 18.1. The Predicted Planetary K
Index is 5, 3, 4, 3, 2, 5, and 6 with a mean of 4. 145, 145, 135,
125, 118, 120, and 110 with a mean of 128.2

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[1]ÿand the ARRL Technical Information
Service web page at,ÿhttp://arrl.org/propagation-of-rf-signals[2]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[3]ÿ. Information and
tutorials on propagation can be found at,ÿhttp://k9la.us/[4]ÿ.

Also, check this:

https://bit.ly/3Rc8Njt[5]

"Understanding Solar Indices" from September 2002ÿQST.


[1] http://www.arrl.org/propagation
[2] http://arrl.org/propagation-of-rf-signals
[3] http://arrl.org/the-sun-the-earth-the-ionosphere
[4] http://k9la.us/
[5] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

04/10/2026

Solar activity remained at low levels this week. Most of the C-class activity came from either Region 4414 or Region 4409, which has developed a delta spot in its intermediary area. All remaining spots were either stable or in slight decay, with Region 4406 rotating over the west limb by the end of the reporting period.
ÿ
Coronal activity was observed in CCOR-1, LASCO and STEREO available imagery during the period. Of the four eruptions, one was far-sided, one was too narrow plus too far north of the ecliptic to have any Earth-directed component, and two had the potential for Earth-directed components. The first was associated with a C2.4 flare from Region 4414 while there was no clear source for the second. Modeling indicates these eruptions will pass behind Earth's orbit and no impact is anticipated. Eruptions potentially associated with the C8.9 are currently being analyzed. Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was on Apr 9th 2026 at 08:45 UTC.
ÿ
Solar activity is expected to be at low levels over April 9 to 11, with a chance for M-class (R1-R2/minor-moderate) flares and a slight chance for X-class (R3/strong or greater) flares, driven primarily by the flare potential of Regions 4409 and 4414. The greatest expected 3 hr Kp for Apr 09 through Apr 11 2026 is 5 (.33NOAA scale G1).

A brief description of Sunspots can be found on the Space Weather
Prediction Center website at, https://www.swpc.noaa.gov/phenomena/sunspotssolar-cycle[1]ÿ.
ÿ
Solar wind parameters reflected the transition out of a waning negative polarity coronal hole high speed stream (CH HSS) into nominal conditions. Wind speeds continued to decline from a peak of ~500 km/s to near 400 km/s by the end of the period.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere, April 9, 2026, by F. K. Janda, OK1HH:

Perhaps the biggest surprise in recent days was that, following the geomagnetic disturbance of April 2-3 (which had been expected, albeit a day earlier and with lower intensity), there were no further major surprises. Solar activity declined as predicted, whereas because it declined over a relatively long period, there was a greater-than-expected drop in critical frequencies in the F2 ionospheric region at mid-latitudes.

For forecasting developments in the second third of April, the 27-day cycle could serve as a relatively reliable guide this time. First of all, one might expect a one- to two-day increase in geomagnetic activity (which is also indicated by the presence of solar coronal holes near the central meridian), followed by relative calm. This is despite the short time that has elapsed since the eleven-year peak of solar activity.

The Predicted Planetary A Index for April 4 to April 10 is 5, 4, 3, 2, 2, 2, and 2 with a mean of 2.8. The Predicted Planetary K Index is 18, 10, 8, 7, 5, 4, and 7 with a mean of 8.4. 10.7 centimeter flux is 106, 105, 108, 110, 115, 115, and 120 with a mean of 111.2.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[2]ÿand the ARRL Technical Information
Service web page at,ÿhttp://arrl.org/propagation-of-rf-signals[3]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[4]ÿ. Information and
tutorials on propagation can be found at,ÿhttp://k9la.us/[5]ÿ.

Also, check this:

https://bit.ly/3Rc8Njt[6]

"Understanding Solar Indices" from September 2002ÿQST.


[1] https://www.swpc.noaa.gov/phenomena/sunspotssolar-cycle
[2] http://www.arrl.org/propagation
[3] http://arrl.org/propagation-of-rf-signals
[4] http://arrl.org/the-sun-the-earth-the-ionosphere
[5] http://k9la.us/
[6] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

Test reply via API

---
þ Synchronet þ MSmac BBS - msmacbbs.maletazul.pt

04/17/2026

Solar activity was at very low levels with only isolated B-class
flaring, mostly from Region 4416.
ÿ
There are currently four numbered regions on the visible disk. Region
4416 remains the largest group by area but exhibited signs of
structural weakening, including flux submergence and a slight decay
of its intermediary pores. Region 4419 was the most complex group on
the disk and showed flux emergence, growth, and divergence within its intermediary spots, leading to the development of a mixed-polarity
gamma configuration. Region 4418 is trending toward plage with only
two small bipolar pores remaining and Region 4415 remained stable.
CMEs observed in coronagraph imagery were determined to be directed
away from Earth.
ÿ
Solar wind parameters reflected waning coronal hole high speed stream influences toward a nominal regime. Solar wind speeds underwent a
gradual, albeit erratic, decline from early-period highs near 420
km/s, to stabilize around 375 km/s by the end of the reporting
period. The phi angle was predominantly oriented in a positive (away
from the Sun) direction.
ÿ
Solar wind parameters are expected to remain primarily near nominal
levels through April 16. Significant enhancements are anticipated on
April 17 with the onset of a co-rotating interaction region (CIR)
that will precede the arrival of a negative polarity high-speed
stream (-CH HSS).
ÿ
Spaceweather.com[1] reports a large hole has opened in the sun's
atmosphere, and it is directly facing Earth. High-speed solar wind
flowing from this coronal hole should arrive on April 18th,
potentially sparking G2-class geomagnetc storms.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere, April 16, 2026, by F. K. Janda, OK1HH:

It is as if we were not just past the 11-year solar activity maximum;
the solar flux fell and remained below 100 s,f,u for five days (April
9-13), while the number of sunspot groups dropped to just three.
Flare activity declined similarly. However, more significant for the
future development of solar activity-and especially for its impact on
Earth-is the large coronal hole No. 42, which is approaching the
central meridian from the northeast. Its western borderÿ can be
considered a potential source of solar wind that will reach Earth in
the coming days.

Initially, it seemed that this would not happen until April 19, but
closer observation of its development shows that the Earth will be
hit by a fast solar wind as early as April 18 during the day. Or
perhaps as early as the late afternoon of April 17, in which case the disturbance could begin with a positive phase (with an increase in
MUF) while shouldÿ continue through the negative phase for much of
the weekend.

The latest solar report from Dr. Tamitha Skov, WX6SWW, can be found
on YouTube.
https://www.youtube.com/watch?v=cOcV9xp8qU8&pp=0gcJCdMKAYcqIYzv[2]

The Predicted Planetary A Index for April 18 to April 24 is 15, 20,
12, 10, 8, 5, and 8 with a mean of 11.1. The Predicted Planetary K
Index is 3, 4, 4, 3, 3, 2, and 3 with a mean of 3.1. 10.7 centimeter
flux is 110, 110, 120, 130, 140, 145, and 145 with a mean of 128.5.
For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[3]ÿand the ARRL Technical Information
Service web page at,ÿhttp://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]ÿ. Information and
tutorials on propagation can be found at,ÿhttp://k9la.us/[6]ÿ.

Also, check this:

https://bit.ly/3Rc8Njt[7]

"Understanding Solar Indices" from September 2002ÿQST.


[1] http://spaceweather.com
[2] https://www.youtube.com/watch?v=cOcV9xp8qU8&pp=0gcJCdMKAYcqIYzv
[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://k9la.us/
[7] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

04/24/2026

Solar activity remained at low levels this past week with numerous C1
flares from Region 4420, which exhibited growth during the period.
Region 4419 showed minor decay, particularly in its trailing spots,
while producing a lone C1.0 flare. Region 4422 was numbered during
the period but remained inactive. No Earth-directed CMEs were
observed in coronagraph imagery.

Solar activity is expected to continue at low levels, with a slight
chance for isolated M-class activity, through April 24, primarily due
to the flare potential from Region 4420 and limb activity.

Solar wind parameters reflected waning coronal hole high speed stream
(CH HSS) influences. The wind speed maintained an average of 525
km/s, and Phi was predominantly in a negative orientation towards the
Sun.

Region 4419ÿ was the most active region of the period, responsible
for 5 out of the 7 C-class flares observed during the week, including
the largest one: a C4.1. The remainder 2 C-class flares of the period
were a C1.1 from Region 4414 and a C1.6 from Region 4416. Coronal
activity was observed during the week with some filament eruptions
and few CMEs without Earth-directed components.

Spaceweather.com[1] reports the sun has been quiet for weeks. That ended
today with two powerful X-class solar flares. In quick succession,
sunspot 4419 unleashed X2.4 (0107 UT) and X2.5 (0813 UT) explosions.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere, April 23, 2026, by F. K. Janda, OK1HH:

Although solar activity during the first four months of this year was
lower than in the previous two years of the 11-year solar maximum
(2024-2025), this was anything but a continuing decline. Periods of
low solar activity gradually tended to lengthen and were interspersed
with sudden increases in both overall and eruptive activity. This
trend is very clearly evident in the solar flux, which was very low
during the penultimate solar cycle (March 14-21), followed by a
further and longer decline shortly after the beginning of April and particularly between April 9 and 13.

Moreover, during the long period of low solar activity (April 5-22), geomagnetic field activity increased (April 18-21), further
diminishing hopes for the usual seasonal improvement in shortwave
propagation conditions. However, two sunspot groups then emerged on
the eastern limb of the solar disk, bringing their total number to
four. Then came Thursday, April 23, with several moderately powerful
solar flares, alternating between the east and west of the solar
disk, preceded by rapid changes in magnetic configuration where the
eruptions were soon observed.

Therefore, in the coming days we will continue to observe increased
solar activity and the potential effects of fast solar wind on Earth.
Shortwave propagation conditions will vary irregularly, while during
the ongoing bursts of intense solar wind, ionospheric attenuation
will increase at higher latitudes.

The Predicted Planetary A Index for April 25 to May 1 is 8, 5, 5, 5,
20, 18, and 12 with a mean of 10.4. The Predicted Planetary K Index
is 3, 2, 2, 2, 5, 5, and 4 with a mean of 3.3. 10.7 centimeter flux
is 115, 120, 125, 125, 125, 125, and 125 with a mean of 122.9.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[2]ÿand the ARRL Technical Information
Service web page at,ÿhttp://arrl.org/propagation-of-rf-signals[3]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[4]ÿ. Information and
tutorials on propagation can be found at,ÿhttp://k9la.us/[5]ÿ.

Also, check this:

https://bit.ly/3Rc8Njt[6]

"Understanding Solar Indices" from September 2002ÿQST.


[1] http://spaceweather.com/
[2] http://www.arrl.org/propagation
[3] http://arrl.org/propagation-of-rf-signals
[4] http://arrl.org/the-sun-the-earth-the-ionosphere
[5] http://k9la.us/
[6] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

05/08/2026

Solar activity was at low levels this past week with occasional
B-class and isolated low-level C-class flares. The largest event of
the period was a C1.4/Sf flare from Region 4429 on May 5.

There are currently six numbered regions on the visible disk as 4434
decayed to plage and Region 4428 rotated beyond the western limb as
an E-type group. The remaining regions mostly showed signs of decay.
Region 4425 appeared stable, though full characterization is
difficult due to extreme limb proximity. Region 4429 showed continued submergence and decay, decreasing in both area and length along with
a total loss of penumbra.

Region 4431 showed some minor new development, with a few small spots
emerging in both polarities following recent decay. Region 4432 had
minor emergence in its intermediate spots, despite an overall gradual
decrease in extent. The remaining regions were mostly stable.

No Earth-directed CMEs were observed in available coronagraph

Flare probabilities increase beginning May 8 as up to two active
regions rotate into view from beyond the eastern limb.
Considering the size of these regions and recent far-side eruptions
seen in coronagraph imagery, solar activity is expected to increase
May 8 - 9 with a chance for M-class (R1-R2/minor-moderate) flares and
a slight chance for X-class (R3/strong or greater) flares.

Solar wind parameters returned to near background levels as transient
coronal mass ejection (CME) influences waned. Solar wind speeds
averaged around 375 km/s. The phi angle was predominantly in a
positive (away) orientation for the majority of the period with a few short-lived oscillations into a negative (toward) orientation during
the period.

Spaceweather.com[1] reports a big and active sunspot hiding behind the
sun's northeastern limb is about to reveal itself, rotating into view
this weekend. A dramatic M2-class solar flare on May 7th confirmed
its approach. The unnamed sunspot has produced at least 5 CMEs in
recent days. If this production continues, Earth could soon be in
line for a solar storm.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere,ÿ May 7, 2026, by F. K. Janda, OK1HH:

Overall solar activity declined slowly but steadily in late April and
early May. Eruptive activity was low, with active regions mostly and
featuring a simple magnetic field configuration. Geomagnetic activity
increased significantly only on May 4, after which the polarity of
the longitudinal component of the interplanetary magnetic field
returned to positive values. The ionosphere returned to a state
favorable for shortwave propagation since May 6.

Solar activity is likely to remain at current levels, while should
decline shortly and slightly in mid-May. Geomagnetically quiet days
can be expected starting May 10 again. Prior to that, there will be a
slight increase in activity, likely on May 8. No other significant
fluctuations are likely.

The latest solar report from Dr. Tamitha Skov, WX6SWW, can be found
on YouTube. https://www.youtube.com/watch?v=lNcaoB7be-k[2]

The Predicted Planetary A Index for May 9 to May 15 is 10, 6, 5, 5,
5, 5, and 25 with a mean of 8.7. The Predicted Planetary K Index is
3, 2, 2, 2, 2, 2, and 5 with a mean of 2.6. 10.7 centimeter flux is
130, 130, 125, 125, 120, 115, and 120 with a mean of 123.6.
ÿ

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[3]ÿand the ARRL Technical Information
Service web page at,ÿhttp://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]ÿ. Information and
tutorials on propagation can be found at,ÿhttp://k9la.us/[6]ÿ.

Also, check this:

https://bit.ly/3Rc8Njt[7]

"Understanding Solar Indices" from September 2002ÿQST.


[1] http://Spaceweather.com
[2] https://www.youtube.com/watch?v=lNcaoB7be-k
[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://k9la.us/
[7] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

05/29/2026

Solar activity has remained at low levels this past week. The largest event of the period was a C3.4 flare originating from Region 4446.ÿ

Solar activity has remained at low levels this past week. The largest event of the period was a C3.4 flare originating from Region 4446.ÿ ÿ There are nine numbered regions on the visible disk. Region 4452 showed notable growth and new flux emergence. Region 4450 decayed to plage, though unassociated transitory pores were observed to its east and west. Region 4443 decayed into a unipolar spot as it approached the west limb following the loss of its leading components. Regions 4453, 4454 and 4455 were numbered during the period. Far-side satellite imagery from Solar Orbiter indicates that Region 4455 is likely a large bipolar group with its trailing opposite-polarity spots still located behind the east limb and was numbered proactively due to its flaring potential. All other regions either continued in slow decay or remained stable. A faint, potentially partial-halo, coronal mass ejection (CME) first seen in LASCO C2 imagery on May 26 and subsequently in GOES/CCOR1 was analyzed. No obvious on-disk source exists. Modeling suggests a possible glancing blow at Earth on May 31. Additionally, narrow eruptions associated with flaring from newly numbered Region 4444 were seen in SUVI imagery but these features are well northward of the ecliptic plane with no Earth-directed components. No other Earth-directed coronal mass ejections (CMEs) were observed in available coronagraph imagery. ÿ Solar activity is expected to be at low to moderate levels through May 30. There remains a chance for isolated M-class flares (R1-R2/minor-moderate) driven by the eruptive potential of the southeast sunspot groups and newly numbered Region 4454. ÿ Solar wind parameters remained slightly elevated and possibly indicative of weak negative polarity coronal hole high-speed stream (-CH HSS)influences.ÿ ÿ Solar wind speeds varied modestly between 350 and 425 km/s. The phi angle was predominantly in the negative sector (towards the Sun), though minor deviations were observed later in the period. ÿ Solar wind parameters are expected to remain mildly enhanced due to weak coronal high speed stream (-CH HSS) influences through May 29. A return toward near-background, nominal conditions is anticipated by May 30. Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere, May 28, 2026 ÿ Observations of the far side of the Sun by the Solar Orbiter probe showed us how a new and relatively large active region was approaching the northeastern limb of the solar disk. But it wasn't until it began to emerge on May 28 (designated as AR 4455) that it became clear the recent rise in solar activity would continue. Furthermore, the only significant coronal hole in the higher northern heliographic latitudes is sufficiently far from other active regions, so we need not expect a significant intensification of the solar wind. Therefore, we could expect calmer conditions in the Earth's magnetosphere and, at the same time, higher usable frequencies in the ionosphere for long-distance communications before their seasonal decline. However, summer in the ionosphere of the Earth's northern hemisphere, with higher attenuation in the lower ionosphere during the long days, will often be enlivened by sporadic E layers in the mid-latitudes until August. ÿ For more information concerning shortwave radio propagation, see
http://www.arrl.org/propagation[1] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[2]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[3] . Information and
tutorials on propagation can be found at, http://k9la.us/[4] .

Also, check this:

https://bit.ly/3Rc8Njt[5]

"Understanding Solar Indices" from September 2002 QST.


[1] http://www.arrl.org/propagation
[2] http://arrl.org/propagation-of-rf-signals
[3] http://arrl.org/the-sun-the-earth-the-ionosphere
[4] http://k9la.us/
[5] https://bit.ly/3Rc8Njt
---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS