ARLP002 Propagation de K7RA


Here’s the latest Propagation Forecast from Tad Cook (K7RA).

Views expressed in this Amateur/Ham Radio news update are those of the reporters and correspondents.

Content supplied by Tad Cook (K7RA), HQ ARRL, and W1AW.

Accessed on 08 January 2021, 2238 UTC, Post 1813.

Source (email message from HQ ARRL and W1AW):

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ARLP002 Propagation de K7RA

Propagation Forecast Bulletin 2  ARLP002
From Tad Cook, K7RA
Seattle, WA  January 8, 2021
To all radio amateurs

ARLP002 Propagation de K7RA

Sunspots disappeared after January 2, so the average daily sunspot
number dropped from 27.1 last week to 10 for this reporting week,
December 31 through January 6.

As a result, average daily solar flux declined as well, from 86.4 to

Geomagnetic indicators remain quiet, with planetary A index changing
from 6.9 to 5.1, and middle latitude numbers from 5 to 4.

This decline was unexpected, and of course we would rather see more
and more sunspots as Solar Cycle 25 progresses, but this is normal. We
expect much variability in any sunspot cycle.

Predicted solar flux for the next 30 days looks depressed, far
different from the high 80s we saw around Christmas. Solar flux is
expected at 74 on January 8-15, 80 on January 16, 82 on January
17-27, 80 on January 28-31, and 78 on February 1-6. Flux values may
rise to 82 around mid-February.

Planetary A index is predicted at 5 on January 8-9, 8 on January
10-11, 5 on January 12-16, 10 on January 17-20, 5 on January 21-24,
8 on January 25-26, 5 on January 27-31, then 10, 10 and 8 on
February 1-3, and 5 on February 4-5. A index may rise to 10 by

This prediction, prepared by the US Air Force, is updated daily,
usually after 2120 UTC, and can be found at, .

Geomagnetic activity forecast for the period January 8 to February
3, 2021 from OK1HH.

“Geomagnetic field will be,

quiet on: January 10, 12-14, 22, 30-31

quiet to unsettled on: January 11, 23, 27-29, February 1

quiet to active on: January 8, 15-16, 21, 24-26

unsettled to active: January 9, 17, 19-20, February 3

active to disturbed: January 18, February 2

Solar wind will intensify on: (January 8-9, 15-17, 19-20,) 21 (- 22,
(23, 25-26,) February 2-3.

“Parenthesis means lower probability of activity enhancement.  The
predictability of changes is lower again, as there are ambiguous and
changing indications. Including rapidly emerging and disappearing
narrow bands of solar coronal holes.”

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 December 31, 2020 through January 6, 2021 were
25, 23, 22, 0, 0, 0, and 0, with a mean of 10. 10.7 cm flux was
81.2, 80.4, 81.5, 80.4, 77.6, 75.1, and 74.1, with a mean of 78.6.
Estimated planetary A indices were 3, 4, 2, 2, 3, 11, and 11, with a
mean of 5.1. Middle latitude A index was 2, 3, 1, 1, 3, 9, and 9,
with a mean of 4.

Hawaii Island Amateur/Ham Radio News:

The Big Island Amateur Radio Club (BIARC) will meet on Saturday, 09 January 2021 via the ZOOM protocol.  The Board meeting begins at 1200 HST, while the general membership meeting is set for 1400 HST.  You can find check in details on the BIARC ListServe.

Doug Wilson (KH7DQ) will begin a new Technician License Preparation Class on 10 February 2021 at 1830 HST.  The class will be using the ZOOM conference protocol.  For details, please go here:

Aloha es 73 de Russell Roberts (KH6JRM)

Public Information Officer

Hawaii County, ARRL Pacific Section


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