Register Account

Login Help

ARRL Propagation Bulletin ARLP043 (2022)

ARLP043 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 43  ARLP043
From Tad Cook, K7RA
Seattle, WA  October 28, 2022
To all radio amateurs 

ARLP043 Propagation de K7RA

Sunspot activity seems listless. Average daily sunspot numbers went
from 57.3 to 58.4 (see note at the end of the bulletin concerning
last week's averages) while solar flux went from 119.6 to 113.2.

On Thursday, the day after the reporting week ended, the sunspot
number was 72, over 13 points above the previous 7 day average.
Perhaps this is a promising sign.

The middle latitude geomagnetic numbers this week are wrong. See
what I mean:

I emailed a contact at NOAA about this, and here is the reply:

"Mid lat numbers are absolutely NOT correct.

"Fredericksburg magnetometer is undergoing maintenance this week and
has been flaky. I've alerted the individual acting in my absence as
well as our developers to see if we can get that cleaned up."

So, the middle latitude numbers presented here at the end of the
bulletin are my own very rough estimates, trying to correlate with
the high latitude and planetary numbers. My NOAA contact emailed me
the data from the Boulder magnetometer, which can be used in lieu of
the Fredericksburg data, and he noted that my estimates were not far

Here is what he sent me:

A index (Boulder)       7, 4, 22, 13, 6, 5, 4 with a mean of 8.7
A index (K7RA estimate) 5, 4, 24, 15, 7, 5, 4 with a mean of 9.1

Average daily planetary A index went from 18.6 to 10.4, and middle
latitude numbers from 8.1 to 9.1.

Predicted solar flux is 125 on October 28 to November 3, 112 on
November 4-5, 118 on November 6-9, 115 on November 10-12, 112 on
November 13-14, 110 on November 15, 108 on November 16-18, 104 on
November 19, 100 on November 20-23, 98 on November 24-25, 100 on
November 26, then 105 on November 27-28, 110 on November 29, 112 on
November 30 through December 2, and 118 on December 3-6.

The rise in solar flux in the first week in November to 160
presented in the previous two bulletins is gone from the current
prediction. But this Thursday solar flux forecast is more optimistic
for the near term than the Wednesday forecast in yesterday's ARRL

Predicted planetary A index is 8, 18, 22, 15, 12, 10 and 8 on
October 28 through November 3, 5 on November 4-9, then 18, 18 and 15
on November 10-12, 5 on November 13-17, then 25, 18, 17 and 12 on
November 18-21, 5 on November 22-23, then 8, 15 and 20 on November
24-26, then 15, 15 and 12 on November 27-29, and 5 on November 30
through December 6.

From F. K. Janda, OK1HH:

"Not much happened on the Sun over the past few days from the point
of view of a terrestrial observer. Overall activity was low. Of
note, the co-rotating interaction region (CIR) hit Earth's magnetic
field on October 22, sparking a G1-class geomagnetic storm and
bright auroras around the Arctic Circle.

"Earth's magnetic field calmed down and active sunspot regions began
to sink beyond the southwestern edge of the solar disk, while others
emerged in the northeast.

"Although helioseismic maps revealed interesting activity on the
Sun's far side, this will likely end before it emerges on the
eastern edge of the solar disk."

Scott, N7KQ in Fort Meyers, Florida wrote:

"I wish I had sent this earlier. I worked Japan twice lately on 10
meters from Southwest Florida. Once on October 12th (JM7OLW) and on
October 18th (JA1KIH) using an indoor dipole above the garage at 14
feet. Both were weak but 100% copy. They both reported the same for
my signal. These contacts were CW, and I run 500 watts."

10 meters has been much better lately, and for Scott, working
stations in Japan is more difficult than for me in Seattle, where we
have always had a pipeline to Japan. His path length is about 7,000
miles, while mine is only about 5000 miles, and I recall during past
sunspot cycle peaks calling CQ running barefoot into a low dipole
produced huge pileups of JA signals.

My own 10 meter CW beacon (K7RA/B, 28.2833 MHz) has been getting
more reports lately. A couple of listeners even mailed QSL cards.

Thanks to Darrel, AA7FV for a tip that led me to a news item about a
gamma ray burst.

Be sure to visit and using the archives feature in
the upper right corner, go to October 18 to read about the October 9
gamma ray burst, and the amateur astronomer who detected it using an
unusual VLF antenna.

This burst of energy happened 2.4 billion years ago and took that
long to reach us.

Here is what stage Earth was in at that time:

More info on the event:

Here is a link to Darrel's own data, labeled Agua Caliente:

Did you know there is crowd sourced geomagnetic data, using smart
phones? You can participate:

Here is a Forbes article on doomsday flares:

Some tabloid news on flares:

Something even worse than a Carrington Event?

In last week's Propagation Forecast Bulletin ARLP042 the averages
were wrong.

The correct averages for the numbers at the end of the bulletin in
ARLP042 were 57.3, 119.6, 10.6 and 8.1 for sunspot number, solar
flux, planetary A index and middle latitude A index respectively.
The wrong numbers were actually from the previous week.

Send your tips, reports, observations, questions, and comments to

For more information concerning shortwave radio propagation, see and the ARRL Technical Information
Service at . For an
explanation of numbers used in this bulletin, see .

An archive of past propagation bulletins is at . More good
information and tutorials on propagation are at .

Instructions for starting or ending email distribution of ARRL
bulletins are at .

Sunspot numbers for October 20 through 26, 2022 were 33, 60, 55, 65,
46, 72, and 78, with a mean of 58.4. 10.7 cm flux was 115.8, 109.4,
105, 108.4, 114.8, 116.3, and 122.4, with a mean of 113.2. Estimated
planetary A indices were 7, 5, 27, 16, 8, 5, and 5, with a mean of
10.4. Middle latitude A index was 5, 4, 24, 15, 7, 5, and 4, with a
mean of 9.1.


Instragram     Facebook     Twitter     YouTube     LinkedIn