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ARRL Propagation Bulletin ARLP038 (2018)

SB PROP @ ARL $ARLP038
ARLP038 Propagation de K7RA

ZCZC AP38
QST de W1AW  
Propagation Forecast Bulletin 38  ARLP038
From Tad Cook, K7RA
Seattle, WA  September 21, 2018
To all radio amateurs 

SB PROP ARL ARLP038
ARLP038 Propagation de K7RA

Sunspots are gone again this week, with none observed since
September 12.

Average daily sunspot number declined to zero this week from 7.6
last week.  Average daily solar flux was unchanged at 68.6.  Average
daily planetary A index declined from 12.6 to 9.7, while average
daily mid-latitude A index went from 10 to 8.3.

The Autumnal equinox is this weekend, at 0154 UTC on Sunday,
September 23, 2018.  The weeks before and after the equinox are
typically a better period for worldwide HF propagation because both
the Northern and Southern Hemispheres are seeing an equal amount of
solar radiation.

For some reason the space weather squadron at USAF has been unable
to transmit their daily 45-day forecast of solar flux and planetary
A index, so we are relying on a recent 27 day forecast from NOAA.

Unfortunately, unlike the daily Air Force prediction, this one is
several days old and only comes out weekly:

Predicted solar flux is 68 on September 21 to 26, 69 on September 27
through October 1, 70 on October 2 to 9, and 69 on October 10 to 13.

Predicted planetary A index is 5 on September 21 and 22, then 16 and
12 on September 23 and 24, 5 on September 25 to 30, 8 and 10 on
October 1 and 2, 5 on October 3 to 6, then 20, 30, 10, 18, 15 and 8
on October 7 to 12, and 5 on October 13.

Here is the latest from Dr. Tamitha Skov:

https://youtu.be/h-a4B1JoeUQ

Mark Lunday, WD4ELG of Greensboro, North Carolina sent an email
titled, "Who says bands are dead?" and a list of stations copied on
15 meter FT8 around 2300 UTC on September 18:

UT0LQ (Ukraine), A41CK (Oman), DL1NKS (Eichenbuehl, Germany), OG1AO
(Finland), SP0QMP (Poland), W0ITT (Missouri), K3JYD (West Virginia),
K4MIA (Florida), CO2RQ (Havana, Cuba) and XE1IM (Michoacan, Mexico).

Mark was using a 40 meter dipole hung at 59 feet.

This week's geomagnetic forecast from OK1HH:

"Geomagnetic activity forecast for the period September 21 to
October 17, 2018

Geomagnetic field will be:
Quiet on September 26 to 28, October 4 and 5, 16 and 17
Quiet to unsettled on September 21, 25, 30, October 3, 12, 15
Quiet to active on September 24, 29, October 2, 6, 11, 13 and 14
Unsettled to active on September 23, October 1, 6, 9 and 10
Active to disturbed on September 22, October 7 and 8

Solar wind will intensify on September 22 to 24, (25), 29, October 1
and 2, 6 to 9

Remarks:
- Parenthesis means lower probability of activity enhancement.
- Reliability of predictions will be low again.

F. K. Janda, OK1HH"

For more information concerning radio propagation, see the ARRL
Technical Information Service at
http://arrl.org/propagation-of-rf-signals.  For an explanation of
numbers used in this bulletin, see
http://arrl.org/the-sun-the-earth-the-ionosphere.

An archive of past propagation bulletins is at
http://arrl.org/w1aw-bulletins-archive-propagation.  More good
information and tutorials on propagation are at http://k9la.us/.

Monthly propagation charts between four USA regions and twelve
overseas locations are at http://arrl.org/propagation.

Instructions for starting or ending email distribution of ARRL
bulletins are at http://arrl.org/bulletins.

Sunspot numbers for September 13 through 19, 2018 were 0, 0, 0, 0,
0, 0, and 0, with a mean of 0.  10.7 cm flux was 69.6, 69, 68.5,
69.1, 67.8, 68.1, and 67.9, with a mean of 68.6.  Estimated
planetary A indices were 17, 16, 8, 6, 11, 6, and 4, with a mean of
9.7.  Estimated mid-latitude A indices were 17, 11, 7, 5, 9, 5, and
4, with a mean of 8.3.
NNNN
/EX