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ARRL Propagation Bulletin ARLP031 (2019)

ARLP031 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 31  ARLP031
From Tad Cook, K7RA
Seattle, WA  August 2, 2019
To all radio amateurs 

ARLP031 Propagation de K7RA

No sunspots were observed over the past week, and solar flux remains
flat, with average daily values declining from 67.3 to 67.
Average daily planetary A index went from 5.3 to 5, and middle
latitude A index from 6.3 to 5.9.
Predicted solar flux for the next 45 days remains at 67, August 2
through September 15, every day.
Predicted planetary A index is 5 on August 2 and 3, then 8, 18, 15,
12 and 8 on August 4 to 8, 5 on August 9 to 16, 8 on August 17 and
18, 5 on August 19 to 26, then 8, 16, 8, 5, 8, 22 and 16 on August
27 through September 2, 5 on September 3 to 12, 8 on September 13
and 14, and 5 on August 15.
Geomagnetic activity forecast for the period August 2 to 28, 2019
from F. K. Janda, OK1HH.
"Geomagnetic field will be:  
Quiet on August 2 and 3, 8, 12 to 15, 21 and 22  
Quiet to unsettled on August 9, 16 and 17, 23, 25  
Quiet to active on August 4 and 5, 7, (10 and 11,) 19 and 20, 24, 28  
Unsettled to active on August 6, (18, 26 and 27)  
Active to disturbed-None! 
Solar wind will intensify on August (2 and 3,) 6-8, (9 and 14,) 27
and 28
Parenthesis means lower probability of activity enhancement." reminds us, "BE ALERT FOR PERSEID FIREBALLS:  Earth
is entering a stream of debris from giant Comet Swift-Tuttle, source
of the annual Perseid meteor shower. Forecasters say the shower
won't peak until Aug. 12 and 13, but already NASA cameras are
catching Perseid fireballs streaking over the USA. The Perseids
produce more fireballs than any other annual shower--largely due to
the size of the parent comet--so your chances of seeing one are
Larry Koziel, K8MU sent this, about simulating the sun in a lab:
Larry and several others including Max White, M0VE reported recently
about solar tsunamis:
George, N2CG in Saddle Brook, New Jersey wrote on July 29:
"So far this year's Summer E's Season daily NA to Europe 6m FT8 mode
openings have mostly bypassed the FN20 and adjacent grids and
favoring the NA South East (especially grids EL and EM) as seen
daily on the DXMAPS Website.
Whatever EU openings I did manage to work so far were short lived
lasting just a few minutes to 20 minutes at best.
However that changed on Sunday July 28, 2019 beginning around 2100
UTC in the NA South East Coast area and around 2200 UTC at my NJ QTH
FN20wv when primarily Finland with a few Sweden and Norway stations
came in with very good FT8 mode signals for over an hour. I managed
to decode the following stations: OH2MA, OH2FQV, OH2FNR, OH3XF,
LA2XPA and SM3CCM and I worked OG2M, OH3SR and OH3XA. This was my
very first time working Finland on 6m and shortly after my QSO with
OH3SR he verified our QSO on LoTW!
August will bring the prime 6m E's Season to a close. However, maybe
the 6m gods have another surprise opening before the end of the
The latest from WX6SWW:
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 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 July 25 through 31, 2019 were 0, 0, 0, 0, 0, 0,
and 0, with a mean of 0. 10.7 cm flux was 68.2, 67.6, 66.7, 67.1,
66.1, 66.2, and 66.9, with a mean of 67. Estimated planetary A
indices were 3, 3, 4, 4, 5, 8, and 8 with a mean of 5. Middle
latitude A index was 3, 4, 4, 7, 5, 8, and 10, with a mean of 5.9.


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