SB PROP @ ARL $ARLP017
ARLP017 Propagation de K7RA

ZCZC AP17
QST de W1AW
Propagation Forecast Bulletin 17  ARLP017
> From Tad Cook, K7RA
Seattle, WA  April 27, 2018
To all radio amateurs

SB PROP ARL ARLP017
ARLP017 Propagation de K7RA

Solar activity increased over the past week, with average daily sunspot numbers
 up from 5.4 to 20 and average daily solar flux rallying from 69.9 to 73.4. The
 previous week saw four days with no sunspots, and the recent week had sunspots
 on every day. New sunspot groups emerged on April 19 and 21.

Predicted solar flux is 69 on April 27-29, 68 on April 30 through May 3, 70 on
May 4-16, 75 on May 17-29, 70 on May 30 through June 10.

Predicted planetary A index is 12 on April 27, 5 on April 28 through May 5,
then 10, 15, 12, 10 and 8 on May 6-10, 5 on May 11-16, then 42, 12 and 8 on May
 17-19, 5 on May 20-22, then 8 and 12 on May 23-24, 5 on May 25 through June 1,
 then 10, 15, 12, 10 and 8 on June 2-6, then 5 on June 7-10.



Geomagnetic activity forecast for the period April 27 to May 22, 2018 from F.K.
 Janda, OK1HH of the Czech Propagation Interest Group.

"Geomagnetic field will be:
Quiet on April 30
Mostly quiet on April 28, May 3, 14, 16, 21-22
Quiet to unsettled on April 27, 29, May 1, 4, 8, 11-13, 19-20
Quiet to active on May 2, 5, 9-10, 15, (18)
Active to disturbed on May 6-7, 17

"Solar wind will intensify on April (27-29), May (2,) 5-7, (8-11,) 17-18,
(19-20).

"Remarks:
- Parenthesis means lower probability of activity enhancement.
- With regard to ongoing changes, current forecasts are less
  reliable again."



Interesting videos with general information on sunspots and solar flares:

http://www.thesuntoday.org/the-sun/solar-acti...

From the same source, multiple detailed images per day of the Sun viewed at
different wavelengths:

http://www.thesuntoday.org/the-sun-now/



Dr. Tamitha Skov will probably release a new space weather video after this
bulletin is sent to ARRL HQ for distribution. This is probably a good place to
check for her latest report:

https://www.youtube.com/user/SpWxfx



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
bat http://arrl.org/bulletins.

Sunspot numbers for April 19 through 25, 2018 were 14, 14, 34, 20, 22, 19, and
17, with a mean of 20. 10.7 cm flux was 70.8, 73, 76.8, 75.7, 73.9, 72.9, and
70.8, with a mean of 73.4. Estimated planetary A indices were 3, 47, 12, 5, 6,
5, and 5, with a mean of 11.9. Estimated mid-latitude A indices were 2, 29, 10,
 5, 6, 4, and 4, with a mean of 8.6.

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...
... If envy were a disease everyone would be sick.
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