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ARRL Propagation Bulletin ARLP006 (2020)

ARLP006 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 6  ARLP006
From Tad Cook, K7RA
Seattle, WA  February 7, 2020
To all radio amateurs 

ARLP006 Propagation de K7RA

We saw a nice run of Solar Cycle 24 and Solar Cycle 25 sunspots from
January 24 through February 1. Daily sunspot number reached a short
term peak of 18 on January  26.

Average daily sunspot numbers declined from 11.1 reported in last
week's propagation forecast bulletin ARLP005 to 4.7 over the current
reporting week, January 30 through February 5.

Predicted solar flux for the next 45 days is 71 on February 7-14, 72
on February 15-20, 73 on February 21-22, 74 on February 23-29, 72 on
March 1-3, 71 on March 4-11, 72 on March 12-18, 73 on March 19-20,
and 74 on March 21-22.

Predicted planetary A index is 8 on February 7, 5 on February 8-24,
10 on February 25-26, 5 on February 27-29, 8 on March 1-3, and 5 on
March 4-22.

Geomagnetic activity forecast for the period February 7 to March 04,
2020 from F.K. Janda, OK1HH.

"Geomagnetic field will be
quiet on: February 12, 15-23
quiet to unsettled on: February 8, 10-11, 13-14, 24, 27, March 1-4
quiet to active on: February 7, (9, 28)
unsettled to active on: (February 25-26)
active to disturbed: none

"Solar wind will intensify on: February 7, 12-15, (16,) 18-20
(21-22,) 26, (March 4).

"Parenthesis means lower probability of activity enhancement."

David Moore sent this:

"Scientists have unlocked one of the mysteries of how particles from
flares on the Sun accumulate at early stages in the energization of
hazardous radiation that is harmful to astronauts, satellites and
electronic equipment. Using data from NASA's Parker Solar Probe,
they observed one of the largest events that shows how plasma is
released after a solar flare can accelerate and pile up energetic
particles generating dangerous radiation conditions."

" ."

AA2F sent this in a message he titled "Martian sporadic-E?"

Ted Leaf, K6HI, Kona, Hawaii sent this:

Jeff, N8II reported on January 31:

"The CQ World Wide 160 Meter CW contest on January 25-26th featured
the best conditions I have ever experienced in a top band test. I
worked 34 outside of NA DX QSOs on the first night and 90 Europeans
the second night running 100W to my half sloper!

"From 0030-0330Z signals were incredibly strong from Europe. I was
able to call CQ and get many EU answers from all over the continent
and was called by P33W in Cyprus and 4X2M in Israel. A total of 26
Germans were logged in the contest. The highlight of the first night
was being called by CX6VM in Uruguay for my best DX of the weekend.

"The solar flux continues to inch higher, but openings on 17M to
Europe are generally poor and just an occasional Mediterranean
opening occurs on 15M around 1500Z."

Latest forecast from Dr. Tamitha Skov, WX6SWW:

If you would like to make a comment or have a tip for our readers,
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

Monthly propagation charts between four USA regions and twelve
overseas locations are at

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

Sunspot numbers for January 30 through February 5, 2020 were 11, 11,
11, 0, 0, 0, and 0, with a mean of 4.7. 10.7 cm flux was 74.1, 73.9,
72.5, 72.2, 72.1, 70.3, and 70.6, with a mean of 72.2. Estimated
planetary A indices were 12, 8, 6, 6, 5, 5, and 5, with a mean of
6.7. Middle latitude A index was 9, 6, 4, 4, 3, 5, and 4, with a
mean of 5.


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