[SFDXA] ARLP014 Propagation de K7RA

Fri Apr 5 15:59:16 EDT 2019

> SB PROP @ ARL $ARLP014
> ARLP014 Propagation de K7RA
> 
> ZCZC AP14
> QST de W1AW  
> Propagation Forecast Bulletin 14  ARLP014
> From Tad Cook, K7RA
> Seattle, WA  April 5, 2019
> To all radio amateurs 
> 
> SB PROP ARL ARLP014
> ARLP014 Propagation de K7RA
> 
> Sunspots have been coming and going, and now this week they
> returned.
> 
> No sunspots were seen from January 31 through March 4, then from
> March 13 to 17, and again March 25 to 30.  They returned on Sunday,
> March 31 but only lasted four days, through Wednesday, April 3.
> Sunspot numbers over that period were 14, 17, 18 and 17.
> 
> Average daily sunspot numbers declined from 16 in last week's report
> to 9.4 this week. Average daily solar flux declined from 75.2 to
> 69.5. Average daily planetary A index rose from 3.7 to 8.4, while
> average middle latitude A index went from 3.9 to 7.3.
> 
> Predicted solar flux is 70 on April 5 to 11, 69 on April 12 and 13,
> 70 on April 14 to 22, then 69, 68, 69 and 69 on April 23 to 26, 70
> on April 27 through May 7, 69 on May 8 to 10, and 70 on May 11 to
> 19.
> 
> Predicted planetary A index is 12, 10, 12 and 8 on April 5 to 8, 5
> on April 9 to 11, then 15 and 8 on April 12 and 13, 5 on April 14 to
> 23, then 10, 8, 5, 8, 10 and 8 on April 24 to 29, 10 on April 30
> through May 1, 8 on May 2 and 3, 10 on May 4, 5 on May 5 to 8, then
> 15 and 8 on May 9 and 10, and 5 on May 11 to 19.
> 
> In last week's bulletin ARLP013 we presented a message from Dr.
> Tamitha Skov, WX6SWW in which she complained about overhyped space
> weather stories in the mainstream press. I think we may have seen
> another example this week from a British tabloid:
> 
> https://bit.ly/2I95JkS
> 
> This was published on Wednesday when the planetary A index was
> slightly unsettled at 12, on Thursday it was 8, and predicted values
> of 12, 10, 12 and 8 follow on April 5 to 8 and 5 on April 9 and 10.
> This is not expected to cause blow outs of "electrical transformers
> and power stations," as mentioned in the article, nor "leave people
> vulnerable to cancer".
> 
> The story was picked up by another UK publication:
> 
> https://bit.ly/2YQ0yMI
> 
> Note they quote Spaceweather.com predicting only "a minor stream of
> solar wind."
> 
> The Washington Post also addressed this issue:
> 
> https://wapo.st/2CHJKxS
> 
> F. K. Janda, OK1HH sends us his geomagnetic activity forecast for
> the period April 5 til May 1, 2019.
> 
> "Geomagnetic field will be: 
> Quiet on April 9, 14, 17 to 19, 
> Quiet to unsettled on April 5 to 8, 16, 20, 26, 
> Quiet to active on April (15, 21 to 23,) 24, 27 to 29, May 1 
> Unsettled to active on April (10 -) 11, 13, 25, 30 
> Active to disturbed April (12) 
> 
> Solar wind will intensify on on April (6,) 12 and 13, 15 and 16, (19
> to 22,) 23 and 24, (25 to 30, May 1)
> 
> Parenthesis means lower probability of activity enhancement."
> 
> Mike Schaeffer, KA3JAW in Easton, Pennsylvania wrote on Thursday
> night:
> 
> "Spring season high frequency band Es is slowly emerging out of its
> dormant state. On Friday, April 5, 0100 UTC (Thursday, April 4, 9:00
> PM EDT local) I was monitoring the 11 meter Citizen Band (27 MHz)
> and noticed a swooshing, light fading condition on channel (28),
> which is normally inactive. All of a sudden like a flick of a light
> switch Es emerged from the states of GA, AL and LA. The average
> distance from Easton, PA was about 1,000 miles. Activity lasted for
> a brief time of about ten minutes. This occurred one hour,
> thirty-two minutes after local sunset (7:28 PM). 10.7cm flux = 70."
> 
> Thanks to John Pieszcynski, W2FV of Trout Lake, Washington for his
> tip on problems with satellite debris during solar minimum, from Dr.
> Tony Phillips of Spaceweather.com:
> 
> https://bit.ly/2CZyxsD
> 
> At 2345 UTC on Monday, April 1 Steve Sacco, NN4X in Florida sent
> this query about something I otherwise heard nothing about:
> 
> "Is there some kind of solar event going on?  I don't see anything
> of note at SolarHam.com.  
> 
> Several folks across the U.S. are hearing an extremely broad-band
> noise in the 30M area. I'm not able to peak it from any heading with
> my 2L Yagi."
> 
> The latest from Dr. Skov:
> 
> https://youtu.be/_dRoznalAg4
> 
> If you would like to make a comment or have a tip for our readers,
> email the author at, k7ra at arrl.net.
> 
> For more information concerning radio propagation, see the ARRL
> Technical Information Service 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-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 March 28 through April 3, 2019 were 0, 0, 0, 14,
> 17, 18, and 17, with a mean of 9.4. 10.7 cm flux was 68.4, 68.8,
> 69.4, 69.5, 69.3, 70.8, and 70.6, with a mean of 69.5. Estimated
> planetary A indices were 11, 7, 4, 11, 8, 6, and 12, with a mean of
> 8.4. Middle latitude A index was 10, 6, 3, 9, 6, 5, and 12, with a
> mean of 7.3.
> NNNN
> /EX