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SB PROP @ ARL
$ARLP044
ARLP044 The
ARRL Solar
Report
ZCZC AP44
QST de W1AW
Propagation
Forecast
Bulletin 44
ARLP044
From ARRL
Headquarters
Newington, CT,
November 21,
2025
To all radio
amateurs
SB PROP ARL
ARLP044
ARLP044 The
ARRL Solar
Report
Solar activity
has remained
low this past
week.
The largest
flare was a
C9.9 on
November 19
from a region
just beyond
the NE limb
near N17.
Region 4284
grew slightly
in the early
part of the
period but was
in decay after
November 19.
New Region
4287 was
numbered. A
Type II radio
sweep
(estimated at
695 km/s) was
observed on
November 19 at
2215 UTC,
likely
associated
with a B9.0
flare from
just beyond
the east limb.
No
Earth-directed
CMEs were
observed.
Solar activity
is expected to
be at low
levels, with a
slight chance
for moderate
levels
(R1-R2/minor-moderate)
to November
21.
Solar wind
parameters
were at
nominal
levels.
Solar wind
speed ranged
from 346 - 421
km/s. Total
field ranged
from 4-8 nT
while the Bz
component was
between +8/-2
nT. Phi angle
was
predominantly
negative.
By late
November 20, a
negative
polarity
coronal hole
high-speed
stream (CH
HSS) is
expected to
become
geoeffective,
causing a
minor
enhancement in
the solar
wind.
Weekly
Commentary on
the Sun, the
Magnetosphere,
and the
Earth's
Ionosphere,
November 20,
2025, by F. K.
Janda, OK1HH:
"Solar
activity over
the last three
months has
fluctuated
fairly
regularly
within an
approximately
27-day period,
determined by
the rotation
of the Sun.
The positions
of active
longitudes do
not change
much, which
makes it
relatively
easy to
predict not
only solar but
also
geomagnetic
activity.
However, we
are still
close to the
11-year
maximum, so
the large
solar flares
on November 9,
10, and 11
were not a
major
surprise.
"However, the
fact that the
coronal plasma
clouds from
the first two
flares merged
(the second,
faster one
caught up with
the first) and
caused a
massive
geomagnetic
disturbance on
November 12
could have
been a
surprise.
"The massive
disturbance
lasted only
until November
13, followed
by alternating
calm days on
November 14-15
and November
18-19 with
turbulent
days, for
which a more
accurate
forecast was
not possible.
We are likely
to see an
increase in
solar activity
during the
third 3rd of
November and
the first 3rd
of December,
with increased
geomagnetic
activity most
likely
expected in
the last days
of November
and the first
days of
December.
However, the
regularity of
fluctuations
in solar and
geomagnetic
activity will
end during
this period,
while it is
advisable to
pay attention
to newly
emerging
active regions
and the shift
of coronal
holes on the
Sun."
High Speed
Stream
activity is
expected to
wane through
November 22.
Solar wind
speeds in the
450-550 km/s
range are
likely based
on recurrent
values.
The
geomagnetic
field is
likely to
reach
unsettled
conditions on
November 22
due to waning
solar wind
enhancements.
Mostly quiet
conditions are
expected on
November 23.
Spaceweather.com for November 21 reports that Sunspot 4274, which caused
the Veteran's
Day aurora and
radiation
storm, will be
back after
Thanksgiving.
The latest
video report
from Dr.
Tamitha Skov,
WX6SWW, can be
found on
YouTube at https://www.youtube.com/watch?v=FOLDm_N6ft8.
The current
Solar Cycle
Progression
from the
NOAA/Space
Weather
Prediction
Center can be
found at www.swpc.noaa.gov/products/solar-cycle-progression.
The Predicted
Planetary A
Index for
November 22 to
28 is 8, 5,
15, 18, 25,
20, and 10,
with a mean of
14.4.
Predicted
Planetary K
Index is 3, 2,
4, 5, 5, 5,
and 3, with a
mean of 3.9.
10.7-centimeter
flux is 110,
105, 110, 110,
110, 120, and
130, with a
mean of 113.6.
For more
information
concerning
shortwave
radio
propagation,
see www.arrl.org/propagation
and the ARRL
Technical
Information
Service web
page at www.arrl.org/propagation-of-rf-signals.
For an
explanation of
numbers used
in this
bulletin, see
www.arrl.org/the-sun-the-earth-the-ionosphere.
Information
and tutorials
on propagation
can be found
at http://k9la.us.
NNNN
/EX
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