ARRL

Secure Site Login

ARRL Propagation Bulletin ARLP027 (2019)

SB PROP @ ARL $ARLP027
ARLP027 Propagation de K7RA

ZCZC AP27
QST de W1AW  
Propagation Forecast Bulletin 27  ARLP027
From Tad Cook, K7RA
Seattle, WA  July 5, 2019
To all radio amateurs 

SB PROP ARL ARLP027
ARLP027 Propagation de K7RA

Solar activity remains very low. Over the past two weeks only four
days had visible sunspots, so average daily sunspot numbers went
from 6.7 in last week's report to 1.6 this week.

Average daily solar flux remained the same, moving only from 67.4 to
67.5. Geomagnetic activity was also flat, with average daily
planetary A index changing from 5 to 4.9, and average daily
mid-latitude A index from 5.7 to 5.1.

Predicted solar flux over the next 45 days is also flat, with solar
flux at 68 on July 5-12, 67 on July 13-19, 68 on July 20 through
August 3, 69 on August 4-5, 68 on August 6-7, 67 on August 8-15, and
68 on August 16-18.

Predicted planetary A index is 18 and 10 on July 5-6, 5 on July 7-8,
then 10, 15, 12 and 8 on July 9-12, 5 on July 13 through August 1, 8
on August 2, 5 on August 3-5, 8 on August 6-7, and 5 on August 8-18.

F.K. Janda, OK1HH sent this geomagnetic activity forecast for the
period July 5-31, 2019.

"Geomagnetic field will be:
Quiet on July 12-16, 25-26
Quiet to unsettled on July 8-9, 17, 20-21, (27)
Quiet to active on July 10-11, (19, 21, 24)
Unsettled to active on July 6-7, (18, 22-23, 28-31)
Active to disturbed on July 5

"Solar wind will intensify on July 5-7, (8-9,) 10-11, (17-19, 22-24).

"Parenthesis means lower probability of activity enhancement.

"Next Geomagnetic activity forecast will be issued on July 18."

Thanks to N7SO for this site:

https://bit.ly/2xvU1dr

Spaceweather.com reported this week that a sunspot from new (next)
Solar Cycle 25 appeared briefly on July 1. This is based on the
polarity of the sunspot (which was visible so briefly that it was
not assigned a number), opposite from spots from current Solar Cycle 24.

So far Solar Cycle 25 sunspots appeared on December 20, 2016, April 8 and
November 17, 2018, May 28 and July 1, 2018.

Several months ago some new solar cycle predictions were published.
Note there is no expectation for another Maunder Minimum:

https://spaceweatherarchive.com/2019/04/10/experts-predict-the-solar-cycle/

On July 1 K1HTV made what may be the first documented Trans-Atlantic
50 MHz 2-way contacts using the new FT4 mode. At 1854Z the first FT4
QSO was completed with F5SSD and 5 minutes later, with IZ8WGU.

Wayne, W2ZDP in Clinton, North Carolina reports: "On 7/1/19,
starting about 1400Z, when I first noticed it at my location in
FM04, 6 meter FT8 was like 20 meter FT8, with Europe coming in all
day long, lasting until about 2000Z

"I'm sure that I'm not the only one to comment on this but I only
have a modest 6 meter station, 100 watts to a 4 element beam at 30
feet. I have never witnessed such a prolific opening to Europe since
I moved from FN02 to FM04.

"When was all said and done, I managed to work 14 countries and 22
grids. This would have been a normal day on 17 meters but on
6...Spectacular!"

If you would like to make a comment or have a tip for our readers,
email the author at, k7ra@arrl.net.

For more information concerning radio propagation, see the ARRL
Technical Information Service web page 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 June 27 through July 3, 2019 were 11, 0, 0, 0,
0, 0, and 0, with a mean of 1.6. 10.7 cm flux was 67, 68.1, 67.6,
67.4, 68.2, 67.3, and 66.9, with a mean of 67.5. Estimated planetary
A indices were 4, 4, 3, 4, 9, 5, and 5, with a mean of 4.9. Middle
latitude A index was 4, 5, 3, 3, 10, 5, and 6, with a mean of 5.1.
NNNN
/EX