[SFDXA] ARLP030 Propagation de K7RA

Fri Jul 25 16:55:01 EDT 2014

> ZCZC AP30
> QST de W1AW  
> Propagation Forecast Bulletin 30  ARLP030
> From Tad Cook, K7RA
> Seattle, WA  July 25, 2014
> To all radio amateurs 
> 
> SB PROP ARL ARLP030
> ARLP030 Propagation de K7RA
> 
> Last Thursday (July 17) had no sunspots at all, a sobering reminder
> of how weak this solar cycle is. We have to go way back to August
> 14, 2011 to find the last spotless day, and there was only one other
> day with no sunspots in 2011, on January 27.
> 
> On July 18 two new sunspot regions emerged, but the sunspot number
> was only 26. Two days later, on Sunday July 20 the sunspot number
> was just 17, and another new sunspot group emerged. On Tuesday two
> new sunspot regions appeared with a sunspot number of 40, and the
> next day, July 23, the sunspot number was 55 and another new one
> emerged.
> 
> Solar flux ranged from a low of 86.1 on July 19 to a high of 99.1 on
> July 23. Outside of those seven days, on July 24 the solar flux was
> 104, and the sunspot number remained at 55.
> 
> Average daily sunspot numbers from July 17 to 23 were only 25.9,
> down from 96.9 in the previous seven day period. Average daily solar
> flux dropped nearly 41 points to 90.3.
> 
> Predicted solar flux for the near term is 110, 115 and 125 on July
> 25 to 27, 140, 155 and 170 on July 28 to 30, then 185, 170, and 155
> on July 31 through August 2, 150 on August 3 to 5, then 145, 140,
> 135 and 125 on August 6 to 9, 120, 115 and 110 on August 10 to 12,
> 105 on August 13 and 14, then dropping down to 85 on August 18, and
> rising to 150 on August 29.
> 
> Planetary A index was quiet over the past week, and is predicted at
> 8 on July 25 and 26, 5 on July 27 and 28, 12 and 10 on July 29 and
> 30, 5 on July 31 through August 4, 8 on August 5 and 6, 5 on August
> 7 to 9, 8 on August 10 and 11, then 5 on August 12 to 16, 8 on
> August 17 and 18, 5 on August 19 and 20, then 10 and 8 on August 21
> and 22.
> 
> F.K. Janda, OK1HH says to expect mostly quiet geomagnetic conditions
> July 25 and 26, quiet to unsettled July 27, quiet July 28, quiet to
> unsettled July 29, quiet July 30 and 31, quiet to unsettled August
> 1, quiet on August 2, quiet to active August 3, quiet to unsettled
> August 4 to 7, quiet August 8, quiet to active August 9, active to
> disturbed August 10, quiet to active August 11, quiet August 12 to
> 15, mostly quiet August 16, quiet to unsettled August 17, mostly
> quiet August 18, quiet August 19, quiet to active August 20 and
> active to disturbed August 21.
> 
> Lots of comments this week asking where the sunspots have gone, such
> as this L.A. Times article, at 
> http://www.latimes.com/science/sciencenow/la-sci-sn-the-sun-goes-eerily-quiet-20140718-story.html
> No sunspots? Sky and Telescope recommends
> observing faculae: 
> http://www.skyandtelescope.com/astronomy-news/observing-news/how-to-see-solar-faculae-072320143/ .
> 
> Thanks to W9WS and TI3/W7RI
> 
> Southgate Amateur Radio Club has a video with recordings of aurora
> communications on 2 meters in Europe ten years ago today, July 25,
> 2004. You can watch it at 
> http://www.southgatearc.org/news/2014/july/sunspot_652_vhf_aurora_in_belgium.htm .
> 
> Ray Soifer, W2RS of Green Valley, Arizona continued comments from
> last week about six meter propagation:
> 
> "Chordal hop Es seems as plausible an explanation as any for my July
> 5 SSB QSO with EA8DBM, but there's a second chapter to this tale: my
> CW QSO the following day, at 1447Z.  Two such openings on successive
> days? Maybe that's why it's the Magic Band: magicians don't reveal
> their tricks.
> 
> Most people who don't live out here (DM41) don't realize how rare
> transatlantic propagation is for us this far southwest in the
> absence of F2. In 5 years on the band from this QTH, I've heard (and
> worked) only two such stations beyond the Caribbean: CU2JT on June
> 24, 2010, and these two QSOs with Alex. I have worked 47 states (all
> but DE, AK and HI) on CW and/or SSB, but Europe doesn't come easy."
> 
> TI3/W7RI made some comments about propagation in Costa Rica:
> 
> "Here in the lower latitudes, we're seeing the expected downward
> trend in propagation due to the current sunspot lull. Propagation on
> 10 meters has been spotty at best - typical of what is normally seen
> at a solar minimum, and the daily 15 meter openings have been
> starting later in the morning, the mid-day break lasting longer, and
> the band closing earlier in the evening.
> 
> Even 20 meters has been rather spartan, and closing completely a few
> hours after sunset on some days - normally, it's open around the
> clock here. Not a huge surprise, given that the 304a index is the
> lowest I have seen it since the last solar minimum - and
> occasionally even lower than it was during much of that time.
> 
> Six meters hasn't seen a single opening from here in Costa Rica into
> the States in over a month, just the occasional, brief opening into
> the Leeward Islands from time to time, sometimes just after sunrise
> - probably Es. Europe, from here in Central America, remains a dream
> for this season, nothing so far. Usually, we've had several good
> openings by this part of the season, but not this year."
> 
> And Pete Corp, K2ARM also reported on 6 meters on July 23:
> "Propagation finally came through for my area in the Northeast. I
> worked 3 more countries plus more stations in other countries I have
> worked before. The 6 meter CW portion was all signals from Europe,
> great operators. It sure looked like F2 but it couldn't be has to be
> E2."
> 
> On July 21 Pete wrote, "Tad, that was very good information on the
> cycles and the days with no sun spots and even though the HF bands
> are poor now and the SFI is only 89, 6 meters opened to Europe this
> morning and even I worked 2 new countries. It seems like E skip
> during the summer can happen most anytime and my records for the
> last 3 years show good openings every 5 or 6 days. Today I could
> copy 10 or more Europeans but could only work the two."
> 
> 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 July 17 through 23 were 0, 26, 27, 17, 16, 40,
> and 55, with a mean of 25.9.  10.7 cm flux was 88.6, 88.5, 86.1,
> 87.1, 90.1, 92.6, and 99.1, with a mean of 90.3. Estimated planetary
> A indices were 5, 3, 3, 3, 5, 5, and 6, with a mean of 4.3.
> Estimated mid-latitude A indices were 6, 4, 3, 4, 5, 6, and 7, with
> a mean of 5.
> NNNN
> /EX
>