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ARRL Propagation Bulletin ARLP022 (2019)

ARLP022 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 22  ARLP022
From Tad Cook, K7RA
Seattle, WA  May 31, 2019
To all radio amateurs 

ARLP022 Propagation de K7RA

No sunspots appeared over this past reporting week, May 23 to 29.
Compared to the previous seven days, average daily solar flux
dropped from 69.8 to 67.4.  Average daily planetary A index
increased from 5 to 7.3, and average mid-latitude A index went from
6.1 to 8.1.
Predicted solar flux over the next 45 days is 70 on May 31, 71 on
June 1, 72 on June 2 to 6, 76 on June 7 to 10, 74 on June 11, 72 on
June 12 and 13, 70 on June 14 and 15, 69 on June 16 and 17, 68 on
June 18, 67 on June 19 to 26, 68 and 70 on June 27 and 28, 72 on
June 29 through July 10, then 70 and 68 on July 11 and 12 and 67 on
July 13 and 14.
Predicted planetary A index is 8 on May 31, 5 on June 1 to 4, 8 on
June 5 and 6, 5 on June 7 to 15, 8 on June 16 to 18, 5 on June 19 to
23, then 10, 16, 12, 10, 10 and 8 on June 24 to 29 and 5 on June 30
through July 14.
When might we see a return of visible sunspots?  Perhaps a table of
recent sunspot numbers and solar flux gives us a clue:
Note when the solar flux dropped below 70, sunspots disappeared.
With predicted flux values above 70 for the first half of June,
perhaps we won't have long to wait.
OK1HH sends us his geomagnetic forecast.
"Geomagnetic activity forecast for the period May 31 thru June 26,
Geomagnetic field will be: 
Quiet on June 13 and 14 
Quiet to unsettled on May 31, June 1 to 6, 9, 15, 19 to 22 
Quiet to active on June 8, 11 and 12, 16 to 18 
Unsettled to active on June 7, 10, 23 to 26 
Solar wind will intensify on (May 31 to June 1,) June 10 to 14, 24
to 26
Parenthesis means lower probability of activity enhancement."
N8II sent us his observations on last weekend's CQ WW WPX CW
contest, from West Virginia:
"Band conditions during the 2 weeks leading up to the WPX CW contest
were quite poor from here except for a few sporadic E openings
including one on 10M phone double hop to OR and WA.
Right from the start, conditions were exceptional.  In the first few
minutes I worked New Zealand and Hawaii on 15 meters, both weak.  20
meters was wide open to almost all of Europe excluding Britain and
France/Benelux countries until about 0115Z, then still open well to
some of EU (northern loud).  Asia conditions improved then including
some Russians in zone 18 and Kazakhstan.  There was some short skip
into the USA and Canada indicating some sporadic E help.  N3QE in MD
nearby reported best ever WPX CW 80M conditions and 40M excellent as
well Friday night.
Saturday morning the sporadic E fun continued as it did throughout
whenever I was operating until the end at 2400Z Sunday.  Also 2 big
gun Japanese stations were logged with good signals around 1240Z.
Over the weekend, I made 204 QSO's on 15M, about 65 USA and Canada,
and 45 QSO's on 10.  The first European to go into the 15M log was
SP8R in Poland at 1256Z followed quickly by UW3U Ukraine.  There
were very few loud EU signals on 15 Saturday, but many that I
struggled to work then were much louder on Sunday.  Conditions
Saturday favored Central EU with Hungary, Czech and Slovak
Republics, Slovenia, Croatia and Italy going into the log.
Amazingly I was able to technically work all continents over the 2
days on both 15 and 10 meters thanks to the multi-hop sporadic E!
P33W in Cyprus was logged on 40 to 10M for Asia, CN3A, Morocco (also
40 to 10M) and CR3DX, Madeira Is. for AF, WH7V on 10 (1853Z
Saturday, very rare) and several Hawaiians on 15 for OC, YW1K,
Venezuela (only SA on 10) for SA, and on 10 YT7Z, Serbia at 1442Z
Sunday along with HG3N Hungary, LZ8R Bulgaria, IB9T Sicily, and CR6K
Portugal for EU.
Each late afternoon Europe boomed in on 20 until past 2400Z
(Friday/Saturday).  At the end there was good sporadic E in almost
every direction.  Both Saturday and Sunday evening there was
essentially no skip zone on 40 vs. the usual one extending into NY,
New England, OH, and NC.  Europe was exceptional on 40M from
2400Z-0200Z Saturday evening with decently low static crashes."
When Jeff mentioned "Benelux", I had to look this up, and no, it
wasn't a typo.  In fact, it has been around since 1944:
Until I read this, I also had no idea that "Luxembourgish" is a
On May 25, Ken Brown, N4SO of Alabama sent this report on recent 40
meter FT8 activity:
"40 Meters FT8 mode, power is 10 watts antenna is a Half Square.
234330 -17 -0.5 1189 ~ CQ YB3BBF OI72 Indonesia
Time represented is 2343 UTC and is before local sunset.
Very unusual time but that is Indonesia open with Caribbean, South
America, and Europe coming through all at the same time.
(Indonesia is very common early morning 1000, 1100, 1200 UTC)
Here is a sample of call signs: 9K2NO, ON4XM, EW8W, JA1EOD, JK7CWL,
I did not work Indonesia, Philippines, or Korea due to them working
the stronger Japanese stations, or others in the local area."
Here is the best article I've ever read describing the solar cycle
prediction panel that met in Boulder in the first week in March, and
"best" includes any of the previous meetings.
The writer makes a common error in confusing the daily sunspot
number with the number of sunspots, no doubt due to the arcane
method for arriving at the number.  She mentions 14 sunspots, but
the sunspot number on the day of the meeting was 14, meaning there
were four sunspots within a single group.  The sunspot number counts
10 points for each group, and one point each for the sunspots within
that group.
Thanks to Paul Drahn, KD7HB for this:
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 May 23 through 29, 2019 were 0, 0, 0, 0, 0, 0,
and 0, with a mean of 0. 10.7 cm flux was 66.5, 66.4, 67, 68, 67.5,
68.1, and 68.2, with a mean of 67.4. Estimated planetary A indices
were 5, 5, 4, 5, 10, 8, and 14, with a mean of 7.3. Middle latitude
A index was 5, 6, 3, 6, 12, 9, and 16, with a mean of 8.1.


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