Secure Site Login

ARRL Propagation Bulletin ARLP050 (2005)

ARLP050 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 50  ARLP050
From Tad Cook, K7RA
Seattle, WA  November 28, 2005
To all radio amateurs 

ARLP050 Propagation de K7RA

Because of the holiday last week, Propagation Forecast Bulletin
ARLP049 went out without the usual weekly data at the bottom. The
data appears at the end of this bulletin.

Average daily sunspot numbers rose over 27 points to 48.1. Average
daily solar flux values were up 9 points. Geomagnetic indices were
on the average lower.

Daily solar flux is expected to stay around 80 until December 5,
when it is expected to decline. The predicted planetary A index for
the next five days is 12, 10, 15, 20 and 20. This indicates
recurring geomagnetic disturbance, especially toward the end of this

If you would like to make a comment or have a tip for our readers,
email the author at,

For more information concerning radio propagation and an explanation
of the numbers used in this bulletin see the ARRL Technical
Information Service propagation page at, An archive of past
bulletins is found at,

Sunspot numbers for November 17 through 23 were 62, 51, 52, 56, 45,
36 and 35 with a mean of 48.1. 10.7 cm flux was 100.5, 101.1, 102,
96.4, 94.7, 92.6, and 89.7, with a mean of 96.7. Estimated planetary
A indices were 3, 4, 10, 7, 3, 6 and 8 with a mean of 5.9. Estimated
mid-latitude A indices were 1, 2, 6, 5, 2, 3 and 12, with a mean of