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ARRL Propagation Bulletin ARLP047 (2018)

ARLP047 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 47  ARLP047
From Tad Cook, K7RA
Seattle, WA  November 26, 2018
To all radio amateurs 

ARLP047 Propagation de K7RA

We saw sunspots return recently, but only for a week, November
13-19. From last week's bulletin, average daily sunspot number rose
from 3.1 to 9.4, while average daily solar flux rose from 68.5 to

That week long sunspot appearance was sunspot number 2727, but last
weekend another smaller sunspot appeared briefly, so brief that it
was not assigned a number, but significant because the polarity was
reversed, so it is a sunspot from the upcoming Solar Cycle 25.

See for details on the brief appearance.

Mike Schaffer, KA3JAW pointed out that this was the second recent
reverse polarity sunspot, after an earlier one on Friday, November

Geomagnetic indicators were quieter, with average planetary A index
dropping from 8.1 to 3.3, while average mid-latitude A index
declined from 6.3 to 2.1.

Predicted solar flux is 69 on November 23-29, 68 on November 30
through December 2, 69 and 70 on December 3-4, 71 on December 5-15,
72 on December 16-17, 71 on December 18, 68 on December 19-29, 69 on
December 30-31, and 71 on January 1-6.

Predicted planetary A index is 5 on November 23-24, 8 on November
25-27, 5 on November 28-30, then 15 and 30 on December 1-2, 10 on
December 3-4, 8 on December 5-6, 12 on December 7-8, 8 on December
9, 5 on December 10-15, then 8, 8, 10 and 8 on December 16-19, 5 on
December 20-27, 15 and 30 on December 28-29, 10 on December 30-31, 8
on January 1-2, 12 on January 3-4, then 8 and 5 on January 5-6.

"Geomagnetic activity forecast for the period November 23 to
December 19, 2018 from F.K. Janda, OK1HH.

"Geomagnetic field will be:
Quiet on November 23-25, 29-30, December 12-15
Quiet to unsettled on November 26, December 3-4, 10, 16, 18-19
Quiet to active on November 27-28, December 11, 17
Unsettled to active on December (1, 5-9)
Active to disturbed on December 2

"Solar wind will intensify on November (23, 30) and on December 1-3,
(4-6,) 7-9, (10-12, 17-18).

"Parenthesis means lower probability of activity enhancement."

From Dr. Tamitha Skov:

"Dear Tad,

"After the horrific fires in southern California this month, the
Thanksgiving holiday holds a very special meaning. As you might have
heard me mention before, several of my friends were recently
evacuated due to the Woolsey fire and one even lost their home in
Malibu Lake. It's no exaggeration when I say it will take years for
their lives to return to normal. I feel very fortunate that my home
was spared.

"While my family and I sit down to dinner and count our blessings
today, I realize my family has grown a bit larger over this past
year. It was just a year ago that I began writing these emails to
you on a weekly basis. Slowly but surely, I've been sharing bits and
pieces of my life with you both here and on Patreon. Many of you
have graciously written back and shared bits and pieces of your life
with me in return. These 'gift exchanges,' as I call them, have
enriched my life so much. So much, in fact, that I can't help but
think of you as part of my family on a day like today.

"So while the Sun takes a breather and gives us a Thanksgiving
reprieve this week, know that you all are in my thoughts. The
current forecast may be a little bit on the dull side while we wait
for a new chance for a solar storm, but I for one, have all the joy
and excitement I need right here.

"Cheers, Tamitha"

D. Moore sent this: .

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
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 November 15 through 21, 2018 were 13, 14, 13,
14, 12, 0, and 0, with a mean of 9.4. 10.7 cm flux was 68.4, 71.1,
73.3, 72.3, 71.1, 70.5, and 68.8, with a mean of 70.8. Estimated
planetary A indices were 2, 2, 1, 3, 4, 6, and 5, with a mean of
3.3. Estimated mid-latitude A indices were 1, 1, 1, 2, 2, 5, and 3,
with a mean of 2.1.


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