[SFDXA] ARLP033 Propagation de K7RA

[WILLIAM MARX]

> SB PROP @ ARL $ARLP033
> ARLP033 Propagation de K7RA
> 
> ZCZC AP33
> QST de W1AW  
> Propagation Forecast Bulletin 33  ARLP033
> From Tad Cook, K7RA
> Seattle, WA  August 13, 2021
> To all radio amateurs 
> 
> SB PROP ARL ARLP033
> ARLP033 Propagation de K7RA
> 
> Solar activity continues to be very weak, and the latest 45-day
> outlook seems to indicate more of the same.
> 
> Sunspots only appeared on three out of the seven days in our
> reporting week (August 5 to 11) and they were not consecutive.
> 
> Average daily sunspot numbers actually rose a little, from 6 to 9.9.
> Average daily solar flux softened from 74.8 to 73.7.  Average daily
> planetary A index went from 8 to 6.3, while middle latitude averages
> were 7, down from 8.7 last week.
> 
> Predicted solar flux over the next few weeks shows a predicted
> maximum of only 75 on just one day, September 11.  The solar flux
> forecast from USAF and NOAA shows 73 on August 13 and 14, 72 on
> August 15 to 19, 73 on August 20, 74 on August 21 through September
> 1, then 73, 72, 72, 74 and 74 on September 2 to 6, 73 on September 7
> to 10, 75 on September 11, 72 on September 12 to 15, 73 on September
> 16, and 74 on September 17 and beyond.
> 
> Predicted planetary A index is 8 on August 13 to 15, 5 on August 16
> to 22, 8 on August 15 and 16, 5 on August 17 to 22, then 8, 12 and 8
> on August 23 to 25, 5 on August 26 through September 1, then 8 and
> 12, on September 2 and 3, then 8 on September 4 to 6, 5 on September
> 7 to 11, then 12, 10, and 10 September 12 to 14, and 5 on September
> 15 to 18.
> 
> Strangely, the planetary A index for September 5 is listed as 58,
> which I was certain was an error.  This outlier value was repeated
> in Thursday's forecast.  Wednesday's prediction was done by Stover
> and Houseal and Thursday's was from Trost and Houseal.  I have not
> checked earlier forecasts to see when this value first showed up.
> New forecasts appear daily at
> ftp://ftp.swpc.noaa.gov/pub/forecasts/45DF/
> 
> OK1HH is gone for another week, so we present geo-forecasts from two
> of his colleagues:
> 
> "Solar activity forecast for the period August 13-August 19, 2021
> 
> Activity level: mostly very low
> X-ray background flux (1.0 to 8.0 A): in the range A3.5 to A7.0
> Radio flux (10.7 cm): a fluctuation in the range 70 to 75
> Events: class C (0 to 2/period), class M (0/period), class X
> (0/period), proton (0/period)
> Relative sunspot number (Ri): in the range 0 to 55
> 
> Geomagnetic activity forecast for the period August 13 to 19, 
> 2021
> 
> Quiet: August 13 to 16, 19
> Unsettled: August 16 to 18
> Active: possible August 16 and 17
> Minor storm: 0
> Major storm: 0
> Severe storm: 0
> 
> Geomagnetic activity summary: 
> Next week, we expect quiet to unsettled conditions generally.  Till
> the next Sunday, August 15, we expect the quiet to unsettled level
> closer to the lower level.
> 
> Since Monday, August 16, more unsettled conditions are possible.
> Between Monday, August 16, and Wednesday, August 18, more unsettled
> conditions are probable.  Within this interval, an isolated active
> event is also possible."
> 
> Interesting item from Southgate Amateur Radio News:
> 
> https://bit.ly/3sd5LNr
> 
> For more information concerning shortwave radio propagation, see
> http://www.arrl.org/propagation and 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/.
> 
> Instructions for starting or ending email distribution of ARRL
> bulletins are at http://arrl.org/bulletins .
> 
> Sunspot numbers for August 5 through August 11, 2021 were 36, 0, 0,
> 11, 0, 0, and 22, with a mean of 9.9.  10.7 cm flux was 74.3, 74.4,
> 73.7, 73.5, 73, 73.3, and 73.8, with a mean of 73.7.  Estimated
> planetary A indices were 3, 7, 11, 5, 5, 7, and 6, with a mean of
> 6.3.  Middle latitude A index was 3, 9, 9, 6, 6, 9, and 7, with a
> mean of 7.
> NNNN
> /EX