[South Florida DX Association] Fw: ARLP023 Propagation de K7RA

[Bill Marx]

> SB PROP @ ARL $ARLP023
> ARLP023 Propagation de K7RA
> 
> ZCZC AP23
> QST de W1AW  
> Propagation Forecast Bulletin 23  ARLP023
> From Tad Cook, K7RA
> Seattle, WA  June 4, 2004
> To all radio amateurs 
> 
> SB PROP ARL ARLP023
> ARLP023 Propagation de K7RA
> 
> The sun appears nearly blank.  Today one small spot, sunspot 621
> faces earth, but there are no other noticeable areas of activity.
> Only two days ago there were several more sunspots, but they are no
> longer visible.  These sunspots didn't rotate off the visible disk,
> but just faded from view.
> 
> Sunspot numbers and solar flux are understandably quite low.
> Average daily sunspot numbers for the May 27 through June 2 period
> was nearly 40 points lower than the daily average for the previous
> seven days.  Over the same period, average daily solar flux was down
> almost seven points.  Fortunately, geomagnetic activity was low.
> Over the weekend conditions were unsettled, but otherwise several
> days had mid-latitude geomagnetic A indices in the single digits.
> 
> Over the next week expect low geomagnetic activity.  Planetary A
> index for June 4-8 is expected at 10, 8, 8, 10 and 10.  Solar flux
> values for the same days are predicted to be 90, 95, 95, 100 and
> 100.  Solar flux is expected to peak between June 11-16 around 110.
> 
> Now that May is over, we should look at some monthly trends over the
> last year.  The monthly average of daily sunspot numbers for May
> 2003 through May 2004 was 89.6, 118.4, 132.8, 114.3, 82.6, 118.9,
> 103, 75.7, 62.3, 75.6, 81, 59.3 and 77.  The monthly average of
> daily solar flux for the same 13 months was 116.6, 129.4, 127.7,
> 122.1, 112.2, 155.5, 140.8, 116.1, 114.1, 107, 112.1, 101.2 and
> 99.8.  Solar flux hit a new monthly low during May for this downward
> side of the solar cycle when it dropped below 100.
> 
> We're in a late spring propagation mode now.  The higher HF bands,
> such as 10 and 12 meters, are seeing fewer openings, although this
> month we should see sporadic E skip.  As the days grow longer,
> absorption during daylight hours should increase.  Daytime
> propagation on 20 meters won't be as good as a few months earlier,
> but late night propagation should improve.  Also during the summer,
> seasonal noise levels increase, probably more noticeable on 160, 80
> and 40 meters.  40 meters should still be good for some long
> distance nighttime propagation.
> 
> Field Day is still several weeks off, but currently the SEC 45 Day
> AP forecast for planetary A index shows unsettled conditions
> predicted for June 26 and 27 with A values of 15.  This is really
> too early to tell, but the picture of conditions for that weekend
> should become clearer as we approach the date.
> 
> For more information concerning propagation and an explanation of
> the numbers used in this bulletin see the ARRL Technical Information
> Service propagation page at
> http://www.arrl.org/tis/info/propagation.html.
> 
> Sunspot numbers for May 27 through June 2 were 62, 52, 57, 64, 54,
> 76 and 63 with a mean of 61.1.  10.7 cm flux was 101.8, 102.4,
> 101.2, 99.6, 95.4, 90 and 90.4, with a mean of 97.3.  Estimated
> planetary A indices were 6, 9, 14, 13, 14, 16 and 11, with a mean of
> 11.9.  Estimated mid-latitude A indices were 5, 6, 12, 11, 11, 14
> and 9, with a mean of 9.7.
> NNNN
> /EX