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ARRL Propagation Bulletin ARLP046 (2002)

ARLP046 Propagation de K7VVV

QST de W1AW  
Propagation Forecast Bulletin 46  ARLP046
From Tad Cook, K7VVV
Seattle, WA  November 8, 2002
To all radio amateurs 

ARLP046 Propagation de K7VVV

Sunspot numbers and solar flux increased last week, when the average
daily sunspot number rose nearly 31 points and the solar flux was up
by nearly 11. Geomagnetic indices have been quite active of late,
although this week was quieter than last. Generally HF operators
appreciate A indices of 10 or lower, but November 1 was the only day
in the past two weeks that the Planetary A index was ever as low as

Lately our planet has been inside a constant solar wind from a
coronal hole. Over the past week conditions haven't been so stormy
that they would produce lower latitude auroras like they did back on
October 24 and 25.

A huge sunspot (number 180) has been squarely earth-directed in the
center of the visible solar disk for the past couple of days, and
the daily sunspot number from Monday through Thursday has risen from
166 to 175, 234 and 259. This sunspot presents a threat of solar
flares. The predicted planetary A index for Friday through Monday is
10, 10, 20 and 20. Solar flux is expected to remain fairly high over
the next few days.

A year ago this bulletin reported that the sunspot numbers were a
small amount lower than this week (less than 4 points) and the solar
flux was about 60 points higher. The latest Preliminary Report and
Forecast of Solar Geophysical Data shows that smoothed solar flux
should be about 44 points lower a year from now, and the latest
prediction for the next solar minimum is around September 2006
through April 2007 for solar flux and centered right around December
2006 to January 2007 for smoothed sunspot number.

Here are monthly averages for solar flux and sunspot numbers for
this year. From January through October, 2002 the average daily
solar flux for each month was 189, 194.5, 154.3, 144.4, 146, 183.5,
191, 206.4, and 153.9. Average daily solar flux for the same months
was 227.3, 205, 179.2, 141.4, 148.7, 174.4, 183.9, 175.8 and 167.

This weekend is the Japan International DX Phone Contest. The object
is for non-JA stations to contact Japanese stations. To work Japan
on 80 meters, try just after local sunset in Japan (around 0748z) to
your local sunrise. For 40 meters, conditions should be good about
an hour earlier than the 80 meter opening until an hour after your
local sunrise. For 20, 15 and 10 meters, check these times:

From Seattle, 20 meters from 1630-1730 and 1930-0500z, 15 meters
2130-0230z, 10 meters 2200-0100z.

From California, 20 meters 1500-1830 and 2000-0730z, getting
stronger later in the second period, 15 meters 2100-0330z, 10 meters

From Salt Lake City, 20 meters 1500-1830 and 2030-0530z, again
stronger during the second period has the hour gets later, 15 meters
2100-0230z, 10 meters 2200-0030z.

From Dallas, 20 meters 1300-1900z (stronger early in the period) and
0200-0530z, 15 meters 2100-0200z, 10 meters 2130-0000z.

From the center of the 48 contiguous United States (centered in
North Central Kansas just south of the Nebraska border) 20 meters
1430-1700z and weaker from 1930-0300z, 15 meters 2100-0130z, 10
meters 2200-0000z.

From Chicago, 20 meters open much of the day, except around
0330-0530z and 1130-1330z, best bet around 0600-1100z, 15 meters
2100-0000z, 10 meters 2200-2230z.

From Atlanta, 20 meters 1300-0300z, with strongest signals toward
the beginning and the end of that period, 15 meters 2100-0100z, 10
meters 2200-2300z.

From Western Pennsylvania/Southern New Jersey, 20 meters 0630-1100z,
1230-0230z with strongest signals 2100-2230 and 0630-1000z, 15
meters 2100-0000z, possible 10 meter opening centered around

From Massachusetts, 20 meters open most hours, best 0630-1330z and
2000-2230z, weakest 0300-0400z, 15 meters 2130-2300z, 10 meters
possible opening in late afternoon.

From Ohio, 20 meters open most hours except 0500-0530z, best signals
around 0600-0900z and 1330-1400z, 15 meters 2100-2330z, 10 meters
possible opening around 2200z.

Sunspot numbers for October 31 through November 6 were 134, 169,
177, 217, 166, 175, and 234, with a mean of 181.7. 10.7 cm flux was
170.2, 162.2, 164.6, 169.2, 177.4, 183.1, and 184.5, with a mean of
173. Estimated planetary A indices were 18, 10, 21, 27, 21, 19, and
19, with a mean of 19.3.


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