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ARRL Propagation Bulletin ARLP003 (2020)

ARLP003 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 3  ARLP003
From Tad Cook, K7RA
Seattle, WA  January 17, 2020
To all radio amateurs 

ARLP003 Propagation de K7RA

Solar Cycle 25 sunspots persisted for the first two days (January
9-10) of this reporting week, January 9-15, with daily sunspot
numbers of 14 and 11. That brought the weekly average daily sunspot
number from 8.4 last week to 3.6. Average daily solar flux edged up
from 71.8 to 72.5.

Average daily planetary A index declined from 6.3 to 5.6, and
average middle latitude A index went from 5.3 to 3.7.

Predicted solar flux for the next 45 days is 72 and 71 on January
17-18, 70 on January 19 through February 7, 72 on February 8-22, and
70 on February 23 through March 1.

Predicted planetary A index is 5 on January 17-18, 8 on January
19-20, 5 on January 21-31, 8 on February 1-2, 5 on February 3, 10 on
February 4-6, 5 on February 7-9, 10 on February 10-11, 5 on February
12-22, 8 on February 23-24, 5 on February 25-27, 8 on February 28-29
and 5 on March 1.

Geomagnetic activity forecast for the period January 17 until
February 12, 2020 by F.K. Janda, OK1HH.

"Geomagnetic field will be:

"Quiet on: January 18, 29-30, February 6-9

"Quiet to unsettled on: January 19-21, 24-28, February 1, 4-5, 10-11

"Quiet to active on: (January 17, 22-23, 31, February 2-3, 12)

"No unsettled to active periods predicted.  No active to disturbed
periods predicted.

"Solar wind will intensify on: January (17, 22-24,) February 2 (-5).

"Parenthesis means lower probability of activity enhancement.  The
predictability of changes is lower again."

N8II wrote, concerning his report in last week's bulletin:

"I forgot to mention that the Jan 9 QSO with LA5MIA was on 20M SSB
versus the Es QSOs on 10M."

Also, from Jon Jones, N0JK:

"Jeff, N8II mentioned conditions on 160M in the Stew Perry contest
'January 28-29.' I am sure he meant December 28-29, 2019.

"His 10M Es reports correlate with the 6M Es occurring. Hope more
winter Es."

Jon Jones, N0JK noted in an email titled "more corrections":

"I made some boo-boos, too.

"K1SIX is in grid FN43.

"KN4NN is in grid EM70. Noted correctly on my FT8 screen shot."

Unfortunately, as this bulletin is text based, we cannot display the
various screen shots and graphics we receive.

N0JK shared late on January 16:

"6 meter Es seemed to vanish after the strong openings the second
week of January. A brief Es opening between Florida and Ohio was
noted January 13 around 1800z by KD4ESV EL87, KW4BY EL96, and
others. AA5B operated MSK144 meteor scatter January 15 from rare
grid DM63.

"January VHF contest this weekend. Jon, N0JK."

It seems we have crossed a threshold. Though solar activity remains
low, recent history shows no Solar Cycle 24 sunspots, only Solar
Cycle 25 activity. I remain optimistic.

Also, with historically low geomagnetic activity, this is a great
time to enjoy 160 meters.

A new forecast from Dr. Tamitha Skov, WX6SWW, can be found at:

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 9 through 15, 2020 were 14, 11, 0, 0, 0,
0, and 0, with a mean of 3.6. 10.7 cm flux was 74.4, 72.8, 73.5,
71.9, 71.5, 71.9, and 71.2, with a mean of 72.5. Estimated planetary
A indices were 12, 7, 6, 4, 3, 3, and 4, with a mean of 5.6. Middle
latitude A index was 8, 6, 4, 2, 2, 2, and 2, with a mean of 3.7.


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