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ARRL Propagation Bulletin ARLP003 (2021)

ARLP003 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 3  ARLP003
From Tad Cook, K7RA
Seattle, WA  January 15, 2021
To all radio amateurs 

ARLP003 Propagation de K7RA

What happened? Solar Cycle 25 seemed well underway, but no new
sunspots emerged since last year prior to Christmas, on December 23,
2020 to be exact. The last time any sunspot was visible was on
January 2. On January 14, posted, "Welcome back,
solar minimum."

Average daily solar flux declined from 78.6 to 73.8. Geomagnetic A
index remained quiet.

Predicted solar flux for the next 30 days is 74, 74 and 75 on
January 15-17, 80 on January 18-21, then 78 on January 22-27, 77 on
January 28-31, 75 on February 1-6, and 74 on February 7-13. Flux is
expected to peak at 78 again after February 14.

Predicted planetary A index is 5 on January 15-16, then 10, 12, 10
and 8 on January 17-20, 5 on January 21-24, 8 on January 25-26, 5 on
January 27-31, 10 on February 1-2, 5 on February 3-12 and 10 on
February 13.

Geomagnetic activity forecast for the period January 15 to February
10, 2021 from F.K. Janda, OK1HH:

"Geomagnetic field will be:
quiet on: January 22, 28-30, February 4, 10
quiet to unsettled on: January 23, 25, 27, February 5-6, 9
quiet to active on: January 15-16, 21, 24, 26, 31, February 1, 3
unsettled to active: January 17-20, February 2, 7-8
active to disturbed: none predicted
"Solar wind will intensify on January (19-20,) 21, (25-27, 31)
February (1,) 2-3.

"Parenthesis means lower probability of activity enhancement.

"The predictability of changes is lower again, as there are
ambiguous and changing indications."

Peering at STEREO spacecraft images via I see a bright spot due to cross a few
days from now, so perhaps that indicates a new sunspot over the
solar horizon. But I have been fooled by bright spots on STEREO in
the past which did not emerge as sunspots.

Jon Jones, N0JK reports E-skip on 6 meters:

"Sporadic-E on 50 MHz dropped off after the first week of January.
There was a sporadic-E opening I found January 10 with K8TB (EN72)
in on FT8 at 1937 UTC.

"On January 14 a rare and unusual opening on 6 meters occurred
between New England, VE1 and Europe. DK8NW and DK1MAX were spotted
at 1415 UTC by WW1L (FN54). HA2NP was spotted by VE1P UTC (FN85) at
1436 UTC.  VE1PZ was spotted by OH6MW at 1430 UTC calling CQ on
50.313 MHz FT8.

"Propagation mode unclear but probably multi-hop sporadic-E. Solar
flux only 73, unlikely to be F2."

A few days ago Dr. Tamitha Skov, WX6SWW, posted this video: .

K9LA gave an excellent presentation on propagation for the Madison
DX Club on Tuesday, and the video will appear here shortly:

Until then, you can also watch a November presentation on Solar
Cycle 25 by Dr. Douglas Biesecker of the NOAA Space Weather
Prediction Center via that same link.

More speculation about Solar Cycle 25:

WB8VLC in Salem, Oregon (CN84lv) sent an extensive listing of DX
worked over the past few months, none of it using FT8, just SSB and
CW. Recently on January 10 using a home made Moxon antenna at 24
feet on 17 meters he worked TZ4AM on CW in Mali at 1903 UTC with 599
signals both ways, and a few minutes earlier at 1857 UTC on SSB he
worked V51WH in Namibia, with S9 signals which persisted for 2

Back in late November on 10 meter FM he worked Brazil, Costa Rica
and Jamaica.

He wrote, "I like to promote the upper bands 10 and 12 meters to
show that they are open more often than one would think."

If you would like to make a comment or have a tip for our readers,
please email the author at, .

For more information concerning radio propagation, see and the ARRL Technical Information
Service web page 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 January 7 through 13, 2021 were 0, 0, 0, 0, 0,
0, and 0, with a mean of 0. 10.7 cm flux was 74.6, 75.2, 74.2, 73.1,
73.2, 72.8, and 73.2, with a mean of 73.8. Estimated planetary A
indices were 6, 2, 3, 3, 14, 9, and 4, with a mean of 5.9. Middle
latitude A index was 4, 1, 2, 3, 10, 8, and 3, with a mean of 4.4.


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