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ARRL Propagation Bulletin ARLP002 (2016)

ARLP002 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 2  ARLP002
From Tad Cook, K7RA
Seattle, WA  January 8, 2016
To all radio amateurs 

ARLP002 Propagation de K7RA

Solar indices were down over the past reporting week (December 31,
2015 through January 6, 2016) with average daily sunspot numbers
down from 49.6 to 41 and average daily solar flux down from 122.3 to

Average daily planetary A index declined from 21.7 to 16.6 and
average mid-latitude A index from 12.6 to 10.6.

Predicted solar flux is 105 on January 8-10, 100 on January 11-12,
95 on January 13-14, then 105, 110 and 115 on January 15-17, 120 on
January 18-21, then 115, 110, 105 and 110 on January 22-25, 115 on
January 26-27, 110 on January 28, and 105 on January 29 through
February 3. Solar flux then peaks for the near terms at 115 on
February 5-6 and again at 120 on February 14-17.

Predicted planetary A index is 8 on January 8, 5 on January 9-11, 12
on January 12, 8 on January 13, 5 on January 14-20, then 8, 15, 12
and 8 on January 21-24, 5 on January 25-30, 12 on January 31, 8 on
February 1, 20 on February 2-3, 12 on February 4, 8 on February 5
and 5 on February 6-16.

Petr Kolman, OK1MGW predicts the geomagnetic field will be quiet to
unsettled on January 8-9, active to disturbed on January 10, quiet
to active January 11, quiet to unsettled January 12-14, mostly quiet
January 15-17, quiet January 18-19, quiet to unsettled January
20-22, mostly quiet January 23, quiet on January 24-26, quiet to
active January 27-28, quiet to unsettled January 29-30, mostly quiet
January 31, quiet to active February 1-2, and quiet to unsettled
February 3.

Petr is less certain about his forecast over the period January

He predicts increased solar wind over January 10-11 and 27-28.

At 2302 UTC on January 4, Australia's Space Weather Services issued
a geomagnetic warning:

"Coronal hole effects are likely to result in periods of active
geomagnetic conditions in the Australian region, with minor storm
levels at higher latitudes.

"Increased geomagnetic activity expected due to coronal hole high
speed wind stream from 06-07 January 2016."

You can subscribe to their various alerts at

Sure enough, as predicted there was increased geomagnetic activity
on January 6-7. The mid-latitude A index on those dates was 12 and
11, the planetary A index was 17 and 14 and the College A index
(Fairbanks, Alaska) values were 27 and 22.

Popular Science this week has a basic article about sunspots:

There was a geomagnetic storm last week, just in time for New Year's
and Straight Key Night:

Participants in Straight Key Night noted the poor propagation
overnight, but said that during New Year's Day conditions improved.

See and select 2016 ARRL
Straight Key Night in the drop-down.

WB2AWQ noted that he used a keyboard, which was actually a piece of
wood with five telegraph keys attached.

Don't miss comments from W0AAA about past SKNs as well as his page.

As usual for SKN, many stations used various vintage gear and keys.

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 the ARRL
Technical Information Service web page at, For an explanation of the
numbers used in this bulletin, see An archive of past
propagation bulletins is at More good
information and tutorials on propagation are at

My own archives of the NOAA/USAF daily 45 day forecast for solar
flux and planetary A index are in downloadable spreadsheet format at and .

Click on "Download this file" to download the archive, and ignore
the security warning about file format. Pop-up blockers may suppress
the download.

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 December 31 through January 6 were 18, 40, 52,
50, 60, 29, and 38, with a mean of 41. 10.7 cm flux was 96.2, 98.4,
100, 101.9, 95.3, 95.2, and 100.2, with a mean of 98.2. Estimated
planetary A indices were 43, 27, 10, 7, 5, 7, and 17, with a mean of
16.6. Estimated mid-latitude A indices were 25, 17, 6, 5, 4, 5, and
12, with a mean of 10.6.


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