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SB PROP @ ARL
$ARLP046
ARLP046
Propagation de
K7RA
ZCZC
AP46
QST
de W1AW
Propagation
Forecast
Bulletin 46
ARLP046
From
Tad Cook, K7RA
Seattle,
WA December 2,
2024
To
all radio
amateurs
SB
PROP ARL
ARLP046
ARLP046
Propagation de
K7RA
ARRL
Headquarters
was closed on
November 29.
So, this
regular Friday
bulletin was
moved to the
following
Monday (12/2).
Solar
activity
increased
during the
current
reporting
week, November
21-27. Average
daily sunspot
number rose to
155.7, and
average daily
solar flux was
282.2.
Weekly
Commentary on
the Sun, the
Magnetosphere,
and the
Earth's
Ionosphere -
November 28,
2024, by F. K.
Janda, OK1HH:
"After
the unexpected
solar proton
flare of 21
November,
which took
place beyond
the Sun's
western limb,
a rain of
higher-energy
protons hit
the Earth's
atmosphere.
This solar
radiation
storm had a
greater impact
at higher
latitudes in
the southern
hemisphere,
where it
caused a
significant
increase in
attenuation.
"Two
days later,
two new large
sunspot groups
appeared near
the
southeastern
limb of the
Sun. These
produced
moderate
eruptions
daily, which
is more or
less normal
for the
11-year
maximum. These
are AR3905 and
AR3906, which
have grown
rapidly to a
size where
they can be
observed with
the naked eye.
There is a
relatively
small coronal
hole near them
that could be
influencing
the solar wind
enhancement.
"Following the
eruption of a
plasma
filament near
AR3901, a G2
class
geomagnetic
storm is
possible on
November
28-29, when a
CME is
expected to
impact.
However,
around 1900 UT
on November
28, when this
information is
written as
usual, nothing
is still
happening. We
will see what
happens next.
It is quite
possible that
the plasma
cloud will
only hit the
Earth a little
and it is also
not out of the
question that
it will miss
the Earth
completely.
So, any
prediction at
this point has
a low
probability of
coming true."
New video from
Dr. Tamitha
Skov, WX6SWW:
https://youtu.be/1P4sCwn8TZI
Send
your tips,
reports,
observations,
questions and
comments to [email protected].
When reporting
observations,
don't forget
to tell us
which mode you
were
operating.
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.
An archive of
past
propagation
bulletins is
at www.arrl.org/w1aw-bulletins-archive-propagation.
More good
information
and tutorials
on propagation
are at http://k9la.us.
Also,
check this
article,
"Understanding
Solar Indices"
from September
2002 QST.
https://bit.ly/3Rc8Njt
Instructions
for starting
or ending
email
subscriptions
to ARRL
bulletins are
at www.arrl.org/bulletins.
Sunspot
numbers for
November 21
through 27,
2024 were 148,
170, 156, 164,
140, 163, and
141, with a
mean of 155.7.
10.7 cm flux
was 166.2,
179.1, 199.9,
202.7, 220.4,
222.3, and
225, with a
mean of 202.2.
Estimated
planetary A
indices were
8, 12, 8, 7,
11, 7, and 5,
with a mean of
8.3. Middle
latitude A
Index was 5,
10, 7, 7, 9,
6, and 3, with
a mean of 6.7.
NNNN
/EX
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