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.

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 QSLed is an Italian time station, as reported here back in June 2012: http://www.hard-core-dx.com/article.php?story=20120617111532649&mode=print


For more information concerning radio propagation, see the ARRL Technical Information Service 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.