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ARRL Propagation Bulletin ARLP028 (2022)

ARLP028 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 28  ARLP028
From Tad Cook, K7RA
Seattle, WA  July 15, 2022
To all radio amateurs 

ARLP028 Propagation de K7RA

Rising solar activity over the past reporting week (July 7 to 13)
was reflected in increased sunspot numbers and solar flux, and
rising geomagnetic activity as well.

Average daily sunspot numbers increased from 62.6 to 102.1, with the
peak value at 134 on Monday, July 11.  Average daily solar flux rose
from 103.5 to 147.4, with peak values at 164.9 and 164.8 on Tuesday
and Wednesday.

A new sunspot emerged on July 7, another on July 10, and one more on
July 11.  Total sunspot area peaked on July 11.

Planetary A index averaged out at 12.4 (up from 9.8 last week) while
the middle-latitude A index went from 9.7 to 10.6.

Toward the end of the UTC day on July 7, Alaska's college A index
was 46, a very high value, while the last four K index readings of
the day and the next two were 6, 6, 7, 5, 5 and 5.

This was caused by a co-rotating interaction region, sparking a G-1
class geomagnetic storm.

Look here for info on co-rotating interaction regions:

The Thursday night prediction from USAF shows improvement from the
Wednesday outlook, with solar flux at 170 on July 15 and 16, 165 on
July 17 and 18, 160 on July 19 and 20, then 155 and 145 on July 21
and 22, 135 on July 23 and 24, then 138 and 148 on July 25 and 26,
150 on July 27 to 29, 160 on July 30 clear out to August 7, then
155, 145 and 135 on August 8 to 10, 138 on August 11 and 12, then
128 and 125 on August 13 and 14, then 130 on August 15 to 17, and
135 on August 18 to 20.

Predicted planetary A index is 8 on July 15 to 21, then 10, 20 and
12 on July 22 to 24, 8 again on July 25 through August 2, then 12
and 10 on August 3 and 4, and 8 on August 5 to 7, then 15, 28 and 12
on August 8 to 10, 8 on August 11 to 17, then 15, 20 and 12 on
August 18 to 20, and 8 on August 21 through the end of the month.

OK1HH wrote:

"Solar activity continued to rise as predicted, a little faster than
we anticipated.  The area of sunspots increased significantly.  We
observed several long and large filaments, especially on July 11 and
12.  Geomagnetically calmer days 9 and 10 and 13 and 14 July were
replaced by G1-Minor Geomagnetic Storm conditions on July 8 and 12.
The influx of protons of solar origin intensified after the July 9
eruption (with a maximum at 1348 UT) lasted until July 12.
Shortwave propagation conditions varied erratically, worst on 8
July, better starting on 11 July."

W5CTD wrote on July 9 that the previous Saturday he was playing
around with a 20 meter Hustler mobile antenna mag-mounted on his

He was puzzled at first when he heard stations calling "CQ Contest",
til he looked it up and found out it was the IARU DX Contest.

Chuck did not mention what mode he used, so I will assume it was
SSB.  He was surprised to work many European stations, in fact, the
list seemed to include all the European countries.

Signals were strong, and he noted that his antenna was
non-directional, and on his car parked on the street.

The opening lasted from 0200 to 0400 UTC, but by 0430 the opening
was over. "One improbable and amazing night."

KS7T in Montana, who I worked recently on 17 meter FT8, sent me this
in an email, which I edited:

"I accidentally came across condx on 15 meter CW during the IARU
contest that I haven't experienced there since the ARRL CW contest
back in February 2000 when I was working Europe from Montana at 2 am
local MST.

20 started showing some signs of fading to EU right before 11 a.m.
local and when that happens my instinct usually switches me to 40
but not this time.  My subconscious was begging me to check out 15.
So I did.  First I heard a B4 (China?), so tuned around expecting to
hear JAs.  There were none, but what I did hear was many
headquarters signals from all over EU.  Had been on 15 earlier in
the daytime and heard and worked two of those plus CR3DX, but that
was it.

I wasn't expecting to work any of those EU stns I just heard because
a lot of them were weak, a few were S9 but fired up on 15 and just
had to give 'em a call.  Well, not only did I work all 19 of them,
but on first call, too.  Had 22 qs in all between 11pm and midnight
on 15.

The other 3 were two VK stns and the B4 who was a struggle.  He got
my call OK but took several minutes to get the 06 through to him.

Last night got on 6 and it had a bit of an opening to the east coast
but just a few 4s and 2 1s were seen.  Worked some 9s and K4RW in

I have 44 states and one JA on 6 meters since 2020 either with my
tribander or a homebrew 6 el vertical beam on the ground running

I don't think I have ever seen a year like this one propagation wise
in my 66 years in ham radio.  It has been quite frustrating at times
but also very surprising, too."

New video a few days ago from Dr. Tamitha Skov:

Next week I hope to get to reports from N2CG about his WM2XCS 8
meter (49 MHz) beacon.

Send your tips, reports, 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 July 7 through 13, 2022 were 80, 81, 89, 113,
134, 117, and 101, with a mean of 102.1.  10.7 cm flux was 121.3,
129.6, 136.9, 153, 161, 164.9, and 164.8, with a mean of 147.4.
Estimated planetary A indices were 20, 19, 6, 7, 12, 18, and 5, with
a mean of 12.4.  Middle latitude A index was 15, 14, 6, 8, 10, 16,
and 5, with a mean of 10.6.


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