ARRL

Secure Site Login

ARRL Propagation Bulletin ARLP030 (2019)

SB PROP @ ARL $ARLP030
ARLP030 Propagation de K7RA

ZCZC AP30
QST de W1AW  
Propagation Forecast Bulletin 30  ARLP030
From Tad Cook, K7RA
Seattle, WA  July 26, 2019
To all radio amateurs 

SB PROP ARL ARLP030
ARLP030 Propagation de K7RA

On Monday July 22 a new sunspot appeared, but just for one day. The
magnetic signature showed it was from the current cycle 24.
 
Average daily solar flux increased insignificantly from 67 to 67.3
this week.
 
Predicted solar flux is 68 for July 26 through August 1, then 67 on
August 2 through September 8.
 
Predicted planetary A index is 8 on July 26 and 27, 5 on July 28
through August 3, then 8, 15, 15 and 8 on August 4 to 7, 5 on August
8 to 18, 8 on August 19 and 20, 5 on August 21, 8 on August 22 to
24, 5 on August 25 to 30, then 8, 15, 15 and 8 on August 31 through
September 3, and 5 on September 4 to 8.
 
Geomagnetic activity forecast for the period July 26 through August
21, 2019 from F. K. Janda, OK1HH.
 
"Geomagnetic field will be: 
Quiet on August 2 and 3, 8, 13 and 14, 21 
Quiet to unsettled on July 26 and 27, 29 to 31, August 1, 9, 15 to 18 
Quiet to active on (July 28,) August 4, 7, (10 to 12,) 19 and 20
Unsettled to active on August 5 and 6 
Active to disturbed - none
 
Solar wind will intensify on August (2 and 3) 7 and 8, (9 to 14)
 
Parenthesis means lower probability of activity enhancement."
 
End of the current cycle, and beginning of the new one:
 
https://www.eurekalert.org/pub_releases/2019-07/ncfa-ot072319.php
 
Max White, M0VNG sent this, about the Solar Wind Composition
Experiment during the Apollo 11 mission:
 
https://bit.ly/2y849cJ
 
The latest video from Dr. Tamitha Skov, WX6SWW.
 
https://youtu.be/Qbqku2_NgDg
 
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 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 July 18 through 24, 2019 were 0, 0, 0, 0, 11, 0,
and 0, with a mean of 1.6. 10.7 cm flux was 67, 66.7, 67, 67.7,
67.3, 67.4, and 67.8, with a mean of 67.3. Estimated planetary A
indices were 3, 4, 3, 8, 8, 6, and 5, with a mean of 5.3. Middle
latitude A index was 4, 3, 5, 9, 11, 7, and 5, with a mean of 6.3.
NNNN
/EX