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ARRL Propagation Bulletin ARLP040 (2018)

ARLP040 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 40  ARLP040
From Tad Cook, K7RA
Seattle, WA  October 5, 2018
To all radio amateurs 

ARLP040 Propagation de K7RA

Sunspots finally returned on September 29, after over two weeks with

Average daily sunspot numbers increased from 0 to 9.6, and average
daily solar flux increased from 67.9 to 68.4 over the past week,
September 27 through October 3.

Average daily planetary A index declined from 10.9 to 7.7, while
average mid-latitude A index changed from 7.9 to 6.1.

Predicted solar flux is 68 on October 5 to 18, 70 on October 19
through November 2, 68 on November 3 to 14, and 70 on November 15 to

Predicted planetary A index is 5 on October 5 and 6, 20 on October 7
and 8, 12 on October 9 and 10, then 10, 8, 5, 12 and 8 on October 11
to 15, 5 on October 16 and 17, then 10, 25, 14, 8 and 12 on October
18 to 22, 8 on October 23 to 25, then 10, 6, 12, 8 and 5 on October
26 to 30, then 8 on October 31 through November 2, then 20, 35, 10,
18 and 15 on November 3 to 7, then 8, 5, 10, 8 and 5 on November 8
to 12, and 5, 10, 25, 15, 8 and 12 on November 13 to 18.

Geomagnetic activity forecast for the period October 05 to 31, 2018
from F. K. Janda, OK1HH.

"Geomagnetic field will be: 
Quiet on October 15 and 16, 29 and 30
Quiet to unsettled on October 12, 14, 27, 31 
Quiet to active on October 5, 10 and 11, 20, 22 to 26 
Unsettled to active on October 6, 9, 17, 28 
Active to disturbed on October 7 and 8, 13, 18 and 19, 21

Solar wind will intensify on October 7 to 9, 11 to 13, 18 to 20, (27
and 28)

Parenthesis means lower probability of activity enhancement."

From Australia's Space Weather Services:


Geomagnetic activity is expected to increase to active levels on UTC
day 7 Oct and to minor storm levels on 8 Oct.  There is a remote
chance that for short periods the geomagnetic activity may even
reach major storm levels during this interval.

The disturbance is due to the expected arrival of CIR (Corotating
Interaction Regions) and HSS (High Speed Streams) associated with a
large recurrent positive polarity north polar connected coronal
hole.  The aurora may be visible on the local nights of the 7 and 8
October from Tasmania, coastline of Victoria and Southwest coast of
Western Australia.


07 Oct:  Active 
08 Oct:  Minor Storm
09 Oct:  Active"

Following the recent temporary shutdown of the solar observatory in
Sunspot, New Mexico, the local newspaper in Alamogordo ran this
article by local astronomer Alan Hale, explaining some solar

Ted Leaf, K6HI had a comment about the K9SQG 40 meter observations
last week.

"Aloha Evan.  40 may be dead for DX but not for NVIS.  We have a
daily 40m net at 4pm local Hawaii time.  Goes all over the islands,
out to more than 200 miles.  Lots of S9+ signals.

For a very low antenna, tell me how well do you get out for DX?"

NVIS is Near Vertical Incidence Skywave propagation).  See .

Evan wrote on September 28:

"Interestingly I've been having nightly schedules on 40M, between
Dayton and Wimberley Texas, a distance of about 1500 miles perhaps,
and signals both ways are +20 to 30 over S9 for an hour or more at a
time.  This is in the 9:30 to 11 pm range, Eastern time.  Going to
try earlier in the evening too and see about that.  Bottom line, 40M
is usable at night but people haven't discovered it yet, hi hi."

On September 28, KD6JUI wrote:

"Hi Tad

Here's your kayak guy.  I was operating today from the boat on 17
and 20m CW.  Using poor wire antenna, but managed two contacts on

However, I was amazed to hear France (F6HKA) and Italy (I8QJU)
coming in loud and clear on 20m CW.  I was unable to get ANY
contacts on 20m, but was surprised to hear these guys coming in like
locals at around 1 p.m. Pacific time.

bil paul, KD6JUI

Operating on the Haas Slough SE of Dixon, CA"

The November, 2016 issue of QST features an article by KD6JUI
describing his kayak operations.

Charles, KW6G wrote:

"The equinox effects are definitely significant.  Wednesday night,
September 26 I worked an ATNO; ZD9CW on Tristan de Cunha Island on
40 meters around 0700 UTC.  Got him on CW on the 3rd call!  I was
running my IC7600 driving an Avon 1010 amp to a ground mounted
Butternut HF9V.  I have copied him last night as well.

Longer propagation does have its advantages!  However, after working
277 DXCC entities, finding new ones during this time of the Sun Spot
Cycle is pretty difficult."

Regarding comments by NN4X last week about noctilucent clouds and
e-skip, Jon Jones, N0JK mentioned that he discussed this subject in
the most recent World Above 50 MHz column in QST.

For more information concerning radio propagation, see the ARRL
Technical Information Service 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 September 27 through October 3, 2018 were 0, 0,
13, 14, 14, 14, and 12, with a mean of 9.6. 10.7 cm flux was 67.1,
69.1, 68.7, 68.3, 70.1, 67, and 68.4, with a mean of 68.4.
Estimated planetary A indices were 7, 8, 10, 6, 9, 8, and 6, with a
mean of 7.7.  Estimated mid-latitude A indices were 6, 8, 9, 4, 6,
6, and 4, with a mean of 6.1.