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ARRL Propagation Bulletin ARLP025 (2018)

ARLP025 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 25  ARLP025
From Tad Cook, K7RA
Seattle, WA  June 22, 2018
To all radio amateurs 

ARLP025 Propagation de K7RA

On Wednesday, June 20 reported the
sudden emergence of Sunspot AR2715. The sunspot number on that day
shot up to 54, and it was 53 the next day. Average daily sunspot
number for the reporting week (June 14-20) was 25.7, up from 4 the
previous week.  Average daily solar flux rose from 69.4 to 74. Solar
flux was 82.1 on June 20.

We have not seen numbers such as this since last September. This is
good news just before ARRL Field Day, assuming the activity does not
produce any geomagnetic disturbance.

Predicted solar flux is 82 on June 22, 80 on June 23-24, 78 on June
25-28, 75 and 70 on June 29-30, 68 on July 1-6, 70 on July 7, 72 on
July 8-13, 74 and 72 on July 14-15, 74 on July 16-20, 70 on July
21-27, 68 on July 28 through August 2, and 72 on August 3-5.

Predicted planetary A index is 5 on June 22-23, then 12, 8, 5, 8,
20, 15 and 10 on June 24-30, 5 on July 1-14, 8 on July 15-16, 5 on
July 17-20, 8 on July 21-22, then 5, 15, 28, 18 and 10 on July
23-27, and 5 on July 28 through August 5.

We saw some heightened geomagnetic activity on Monday, June 18 UTC
when the planetary K index rose to 5, and later in the day Alaska's
College K index hit 6 over two of the eight 3-hour periods for the
day. College A index was 33.

Jeff Hartley, N8II of Shepherdstown West Virginia sent this report
yesterday, June 21:

"Today we are finally taking a breather from widespread sporadic-E
openings to many different areas. The best 10M opening I have worked
so far was on June 4 when I worked 72 European stations on SSB with
best DX into Poland, Slovak Republic, and Greece (most EU stations
ever worked by me in single Es opening). Quite a few were running
25W or less and I worked all of the UK countries except Jersey which
was self-spotted, incredible!

"On the morning of June 17, I heard about 15 Italian stations on 10M
CW and SSB working the Italian 10M contest; none would stop long
enough to answer my calls. But, after returning from the W3LPL open
house, I started making QSOs for the WV QSO Party on 10M SSB and
there was IT9ACN at 2207Z calling CQ in his contest and he was
thrilled to work me; he and his Sicilian friend IT9BUN were both
about S8 with QSB. I went on to work another IT9, IK7, and MM0TFU
(weak) in Scotland along with 19 USA stations to the west and south.
After a QSY to 15M, a station from northern Spain called in and
quite a few EU stations were worked in the 2300 and 2400Z hours on
20M SSB along with many Es QSOs into all W4s (except VA/NC), OH, MI,
all W9s, all W5s, and NY plus all New England states.

"The party continued on 10M SSB on the June 17 working KW2W in VT at
1309Z and then on 15M CW, HV0A Vatican (first HV in over 1-1/2
years) via probable Es.  Then back to 10M SSB double hop Es opened
by 2333Z to Steve, WB2WIK in Los Angeles also working 2 other SOCAL
stations, and on single hop QSOs with FL, KS, MO, IL, AL and MS.

"On June 18 starting at 2039Z on 10M CW I found and worked F5NBX
France, M0BKL England, and IK1ZOC Italy. Then starting 2215Z on 10
SSB I worked WP4PPV Puerto Rico, ME, and FL.

"On June 19 starting 2024Z on 10 CW, I found HB9BKL Switzerland,
M0BKL again, and was called by IU4FJI Italy. Then I switched to 10
SSB to work 2E0IQD, England and I5KAP in Florence.

"June 20 featured very intense sporadic-E for many hours returning
to 10M SSB at 0123Z putting K7CAR at a state park in UT, and another
UT, CO, AZ, KY, MI and many 4s, 5s, 9s and 0s in the log. Almost all
day long during the daytime into late evening there was widespread
Es, but I was too busy until 2350Z to operate when I worked MN, NY
grid FN13 (very unusual), VE3TM FN25, and MO on 6 meters. Then it
was down to 10 SSB to work several southern VE3s, Eastern TN,
western NC, MI, OH, TN, MI, MO, GA, and several other FL stations
going QRT at 0120Z. I saw Midwest to EU QSOs reported on 6M around

Mike Treister, W9NY of Chicago wrote:

"Interesting about the increased sunspots. Have heard a lot of skip
- few hundred miles - from all directions on 6 and 10 the past few
days. Some pretty astounding signal strengths too. Nice to see so
many on the air - lots of obvious new hams who have not previously
worked 6 or 10 meter skip very excited with their QSOs. Almost more
enjoyable listening than working the stations!"

New report from Dr. Tamitha Skov:

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 web page 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 June 14 to 20, 2018 were 16, 13, 13, 15, 28, 41,
and 54, with a mean of 25.7. 10.7 cm flux was 72.4, 70.6, 70.5,
72.3, 73.7, 76.6, and 82.1, with a mean of 74. Estimated planetary A
indices were 5, 4, 3, 5, 19, 6, and 5, with a mean of 6.7. Estimated
mid-latitude A indices were 7, 6, 4, 7, 20, 6, and 7, with a mean of


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