Here’s the latest Amateur Radio propagation forecast from Tad Cook (K7RA).
Views expressed in this Amateur/Ham Radio propagation update are those of the reporters and correspondents. Accessed on 01 October 2022, 0326 UTC.
Content republished with permission of The ARRL. Copyright ARRL.
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ARLP039 Propagation de K7RA
QST de W1AW
Propagation Forecast Bulletin 39 ARLP039
From Tad Cook, K7RA
Seattle, WA September 30, 2022
To all radio amateurs
SB PROP ARL ARLP039
ARLP039 Propagation de K7RA
Sunspot activity rose this reporting week, September 22-28, with
average daily sunspot numbers increasing from 68 to 105.1. But solar
flux? Not so much. Average daily solar flux rose from 134.3 to
So, the sunspot average rose 55% and solar flux only 3%. I usually
expect the numbers to track more closely.
New sunspots appeared on September 22 and 23, and one more on
September 27. On Thursday night (September 29) NOAA reported the
daily sunspot number at 56, little more than half the average for
the previous seven days, which is 105.1.
Tuesday September 27 had lots of geomagnetic activity, with the
planetary A index at 24 and middle latitude at 33. Spaceweather.com
blamed an unexpected CME. They also report a huge sunspot beyond the
Sun’s eastern horizon with a helioseismic image at,
The Australian Space Weather Forecasting Centre issued a geomagnetic
warning at 2146 UTC on September 28:
“Geomagnetic 27 day recurrence patterns indicate that G1 geomagnetic
activity is likely during the interval 30-Sep to 02-Oct.
“INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL HOLE HIGH
SPEED WIND STREAM.”
Predicted solar flux from the Thursday night forecast appears much
more optimistic than the Wednesday numbers, which were in the ARRL
Letter on Thursday.
Instead of 135 and 130 for the next few days, they are 148 on
September 30, 146 on October 1-4, 140 on October 5-7, then 135, 130,
128 and 132 on October 8-11, then 136 on October 12-13, then 138,
140, 138 and 135 on October 14-17, then 132, 130, 128 and 125 on
October 18-21, then 130, 140, 142 and 145 on October 22-25, and 140,
135, 130, 125, 128 and 130 on October 26-31, then 132 on November
1-3, and 135, 130 and 128 on November 4-6.
Planetary A index is predicted at 20, 60 and 40 on September 30
through October 2, then 20, 18, 16 on October 3-5, 12 on October
6-7, then 8 on October 8-14, 10 on October 15-16, 8 on October
17-19, 12 on October 20-21, 8 on October 22-23, 10 on October 24-25,
8 on October 26-27, then in a recurrent disturbance as sunspots
rotate into the same position as weeks earlier, 25, 50, 30, 20, 12
and 10 on October 28 through November 2, and back to 8 on November
Of course, a planetary A index of 50 or 60 is huge, indicating an
expected major geomagnetic disturbance.
“Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s
Ionosphere – September 29, 2022.
“Free continuation of predictions of the Earth’s magnetic field
activity, published in the years 1978 – 2021.
“The following text is very brief as I am traveling around Europe
without a computer. I will add more next time.
“An unexpected and unpredicted surprise was the rise of geomagnetic
activity during the night of September 24-25.
“Further developments did not take place according to assumptions.
Which, by the way, is a precursor to the next increase in solar
“Nevertheless, I present a forecast of further disturbances:
September 30 and especially October 1!
“http://ok1hh.nagano.cz/ – F.K. Janda, OK1HH”
Wow, Frantislav manages to submit his report without a computer!
I’ve never been to Europe (unfortunately), but I imagine him ducking
into some sort of Internet kiosk to file his report.
Here is Dr. Tamitha Skov’s, WX6SWW, the Space Weather Woman, report
from last weekend:
An article on solar research:
Newsweek is at it again:
I continue to see unusual propagation using FT8, such as my signal
only being received in a narrow band 100-200 miles wide on the East
Coast of North America.
You do not need to be an FT8 user to use it to check out the bands.
Just go to the pskreporter map page at
interested in (they even have 11 meters!).
Next, select the default “Signals” and “Sent/Received by” and change
“the callsign” to “grid square,” entering your own four-character
grid (or one near you with a larger ham population) and in the
“Using” field select FT8.
Hit “Go!” and you will see where stations in your area are being
received, including signal levels.
You can enter your own call instead of the grid, and select “Country
of Callsign,” and you will see activity all over your nation. I find
it interesting early in the day to use this on 10 meters, and what I
usually see is activity all over the East Coast, and especially in
the southeast U.S. but not here on the west coast.
But I know that the 10 meter openings will advance across the
country with the movement of Earth relative to our Sun.
Explore the “Display options” link just to the right of the time
listed in the “over the last” field, and you can customize this
tool. I like to select “Show time text in black always,” “Show
connecting lines always,” and “Show SNR.”
The “Show logbook” link is very useful, once you have done a search.
Often, I will use this, searching for the callsign of an FT8 station
who has mysteriously disappeared after connecting to me. I can sort
the entries by Time to find out if anyone has received that station
since I last saw that station’s signal.
The default “over the last” setting is 15 minutes, but when
searching for a callsign you can vary the time over the past 24
Send your tips, reports, observations, questions, and comments to
For more information concerning shortwave radio propagation, see
Service at http://arrl.org/propagation-of
explanation of numbers used in this bulletin, see
An archive of past propagation bulletins is at
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 September 22 through 28, 2022 were 99, 111, 128,
96, 120, 110, and 72, with a mean of 105.1. 10.7 cm flux was 136.7,
146.3, 146.5, 134.7, 135.1, 134.5, and 134.8, with a mean of 138.4.
Estimated planetary A indices were 6, 12, 13, 7, 6, 24, and 5, with
a mean of 10.4. Middle latitude A index was 5, 12, 10, 5, 5, 33, and
3, with a mean of 10.4.