ARRL

ARRL Propagation Bulletin ARLP049 (1998)

SB PROP @ ARL $ARLP049
ARLP049 Propagation de K7VVV

ZCZC AP49
QST de W1AW  
Propagation Forecast Bulletin 49  ARLP049
From Tad Cook, K7VVV
Seattle, WA  December 4, 1998
To all radio amateurs 

SB PROP ARL ARLP049
ARLP049 Propagation de K7VVV

HF radio conditions were good over the past week, with moderate
geomagnetic conditions and a rising solar flux.  Sunspot averages
for the week were more than double the week before, and average
solar flux was up over thirty points.  The high point for the week
was on Sunday, when solar flux reached 167.8, which was the highest
it's been since the beginning of September.  Average solar flux for
the previous ninety days was 131 and 132, and solar flux was above
this level on every day, indicating an upward trend.

Now that November has passed, we can see that solar activity is back
up, after a dip in October.  Monthly average solar flux for June
through November was 108.5, 114.1, 136, 137.7, 117.3 and 138.8.

For the next three days, Friday through Sunday, look for a solar
flux of 150, 148 and 148 with a planetary A index around 10 for all
days.  After the weekend solar flux should dip just below 130 around
December 9, then bounce around between 130 and 135 until December
17.  From December 18 until December 27 flux values should rise to
around 150.

N7SO writes to remind us of the NASA Space Weather Bureau website at
spaceweather.com.  There is a lot of data on current conditions, as
well as a great 10 day animation of the sun at
http://spaceweather.com/java/solar-anim.html.  Don't miss the
current image of the aurora updated every seven minutes, as well as
information on solar flares.

Sunspot Numbers for November 26 through December 2 were 132, 121,
110, 126, 186, 153 and 144 with a mean of 138.9.  10.7 cm flux was
156.4, 158.9, 164.8, 167.8, 163.4, 162.7 and 151.7, with a mean of
160.8, and estimated planetary A indices were 11, 8, 5, 6, 13, 13
and 4, with a mean of 8.6.
NNNN
/EX