SB PROP @ ARL $ARLP015
ARLP015 Propagation de K7RA

ZCZC AP15
QST de W1AW
Propagation Forecast Bulletin 15  ARLP015
> From Tad Cook, K7RA
Seattle, WA  April 14, 2017
To all radio amateurs

SB PROP ARL ARLP015
ARLP015 Propagation de K7RA

Solar indicators, both sunspot numbers and solar flux, both dropped this week,
in fact on April 8 there were no sunspots. Average daily sunspot numbers
declined from 65.9 to 16.6, and average daily solar flux went from 96.5 to
73.8, compared to the previous seven days, .

Average daily planetary A index went from 15.6 to 10.6, and average daily
mid-latitude A index declined from 13 to 9.3.

Predicted solar flux shows 75 on April 14-15, 85 on April 16-17, 80 on April
18, 95 on April 19-21, 92 on April 22-23, 90 on April 24-29, 80 on April 30, 78
 on May 1-2, 72 on May 3-4, 75 on May 5-6, 72 on May 7-12, 75 and 85 on May
13-14, 88 on May 15-16, 95 on May 17-18, 92 on May 19-20, and 90 on May 21-26.

Predicted planetary A index is 8, 10 and 8 on April 14-16, 25 on April 17-18,
12 and 8 on April 19-20, 5 on April 21-22, then 55, 28, 20 and 22 on April
23-26, then 28, 15, 8 and 5 on April 27-30, then 20, 10, 8 and 10 on May 1-4,
15 on May 5-6, 12 on May 7, 8 on May 8-10, 5 on May 11-13, then 20, 18 and 10
on May 14-16, 5 on May 17-19, then 55, 28, 20, 22, 28, 15 and 8 on May 20-26.

F.K. Janda, OK1HH sent us his geomagnetic activity forecast for the period
April 14 to May 9, 2017.

"Geomagnetic field will be:
Quiet on April 16, 20-22, 30, May 5, 9-10
Mostly quiet on April 14-15, 21, May 3-4, 6
Quiet to unsettled April 19, 29, May 1, 2, 7, 8
Quiet to active on April 23, 25-28
Active to disturbed on April 17-18, 24

"Amplifications of the solar wind from coronal holes are expected on April
(15,) 16-19, 24-27

"Remark: - Parenthesis means lower probability of activity enhancement and/or
lower reliability of prediction."



Doctor Tamitha Skov's latest video concerning space weather can be found at:

http://bit.ly/2pwQIwu



Bil Paul (I think he must be KD6GUI) wrote on April 7:

"The high solar flux number for Wednesday, April 5 (around 95) didn't seem to
translate into good propagation. I was out in my kayak trying to qualify an
island in Northern California for U.S. Islands on the Air, running my usual 10w
 into an end-fed half-wave wire vertical (won't even get into how I can set
that up while operating from kayak!).

"As usual, started operating on 17m SSB. One contact told me I was the only
signal he was hearing on the entire band. Only obtained 3 contacts on 17
(SSB/CW), then went down and tried 20m. I could hear Europe and South America
coming in on SSB, but from my little pistol setup, I only found 3 more contacts
 before I rolled up the rug and went QRT.

"But it's encouraging that the SF is often predicted to be running considerably
 higher for the next 30 days or so.

"I don't know if you read CQ magazine, but I have an article in the April issue
 about a 91-year old ham/navy vet in PA who intercepted Japanese code
transmissions in Alaska during WWII."




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-ionosph...

An archive of past propagation bulletins is at
http://arrl.org/w1aw-bulletins-archive-propag... 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 April 6 through 12, 2017 were 38, 27, 0, 13, 13, 12, and
13, with a mean of 16.6. 10.7 cm flux was 75.7, 73.9, 73.1, 74.4, 73.6, 74.6,
and 71.4, with a mean of 73.8. Estimated planetary A indices were 7, 10, 16,
18, 5, 12, and 6, with a mean of 10.6. Estimated mid-latitude A indices were 5,
 9, 14, 16, 5, 10, and 6, with a mean of 9.3.

NNNN
/EX

)\/(ark

Always Mount a Scratch Monkey
Do you manage your own servers? If you are not running an IDS/IPS yer doin' it
wrong...
... We spend billions on games of chance, not including weddings.
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