ARRL

ARRL Propagation Bulletin ARLP017 (2014)

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 25, 2014
To all radio amateurs 

SB PROP ARL ARLP017
ARLP017 Propagation de K7RA

Average daily sunspot numbers during the past week rose 84.3 points,
from 118.4 to 202.7. Average daily solar flux was up 11.3 points to
160.4.

The predicted average solar flux on April 19 for the next four days,
April 24-27, was 150, but this was downgraded yesterday. On April 23
the average for the same period was adjusted down to 122.5, and on
April 24 the average over the same period was 123.3. Of course that
latest average now included one known value, the actual solar flux
for April 24, which was 130.1.

The latest projection has solar flux at 125, 120, 118, 115 and 112
on April 25-29, 110 on April 30 through May 2, 155 on May 3-4, then
160, 165, 160, 155 and 150 on May 5-9, then 155 on May 10-14, 150 on
May 15-17, and 165 on May 18.

Predicted planetary A index is 8 on April 25, 5 on April 26 through
May 13, followed by 10, 8, 15, 25, 20 and 10 on May 14-19, and 8 on
May 20-22.

Petr Kolman, OK1MGW of the Czech Propagation Interest Group on April
24 predicted geomagnetic conditions to be quiet to unsettled on
April 25-26, mostly quiet April 27-30, quiet May 1-2, mostly quiet
May 3, quiet to unsettled May 4, quiet May 5, quiet to unsettled May
6, quiet May 7, quiet to active May 8-9, quiet to unsettled May
10-11, mostly quiet May 12-13, quiet to unsettled May 14-15, quiet
to active May 16-17, quiet to unsettled May 18, and mostly quiet May
19-21.

Http://www.spaceweather.com reported today, "Departing sunspot
AR2035 erupted on April 25 at 0032 UT, producing a strong X1.3-class
solar flare and an HF communications blackout on the dayside of
Earth. NASA's Solar Dynamics Observatory recorded a flash of extreme
ultraviolet radiation from the explosion. The explosion also
produced a CME, but because the blast site was so close to the Sun's
western limb, the cloud is not heading toward our planet. The chance
of a geomagnetic storm remains low."

Check
http://origin-www.swpc.noaa.gov/news/sun-solar-maximum-solar-cycle-24-seeing-second-higher-peak-sunspot-number
for a graph showing that the current solar cycle is at a second
peak, higher than the first.

NOAA also released this several days ago, concerning their website
redesign:

"NOAA's Space Weather Prediction Center is pleased to debut the Beta
version of its new website at http://origin-www.swpc.noaa.gov. This
completely redesigned site leverages the latest web technologies to
reach the broadest possible audience. As a Beta release, the site
incorporates the look-and-feel of the final site with major
functions and content included. It is still in development and we
are adding new content and capabilities nearly every week.

"To help in our continued development and ultimately our final
deployment, we are looking to our users for feedback. This includes
feedback on the general usability (look-and-feel, functionality) as
well as the content (suggestions, missing, corrections). We won't be
able to incorporate all suggestions, but they will certainly guide
us as we move to our final, polished release. A feedback link is
provided at the upper right or just go to
http://origin-www.swpc.noaa.gov/content/contact-us."

David Crawford, KF4VXJ of Raleigh, North Carolina sent another
report regarding WWV: "I did notice other stations under WWV's 10
MHz signal, possibly from South America and Italy. In January this
year when propagation took out WWV's signal on 10 MHz in the
evening, I was able to ID and get a QSL card out of the Italcable in
Viareggio.  The Italcable station's signal consists of music
snippets and time pips, with an ID sent by CW giving a web address.
Hearing foreign stations under WWV might be an indication that 30
meters could be open for DX.

"Hopefully we'll have some decent propagation for Field Day 2014."

The station that David heard and QSL'd is an Italian time station,
as reported here back in June 2012:

http://www.hard-core-dx.com/article.php?story=20120617111532649&mode=print

Otherwise, there were no other reports this week.

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 the
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 April 17 through 23 were 296, 263, 259, 192,
168, 136, and 105, with a mean of 202.7. 10.7 cm flux was 178.9,
172.3, 169.3, 162.5, 158.8, 144.8, and 136.1, with a mean of 160.4.
Estimated planetary A indices were 11, 8, 15, 22, 18, 5, and 7, with
a mean of 12.3. Estimated mid-latitude A indices were 11, 7, 13, 20,
18, 4, and 6, with a mean of 11.3.
NNNN
/EX