ARRL

ARRL Propagation Bulletin ARLP046 (1999)

SB PROP @ ARL $ARLP046
ARLP046 Propagation de K7VVV

ZCZC AP46
QST de W1AW  
Propagation Forecast Bulletin 46  ARLP046
From Tad Cook, K7VVV
Seattle, WA  November 12, 1999
To all radio amateurs 

SB PROP ARL ARLP046
ARLP046 Propagation de K7VVV

Both solar flux and sunspot numbers were up this week, with average
sunspot numbers rising nearly 37 and average flux up by nearly 25.
Activity took a big jump in the past few days, with a sunspot number
of 343 on Wednesday and solar flux at 248.5.  Unfortunately for HF
operators, this was accompanied by rising geomagnetic activity, so
conditions have not been ideal.

Perfect conditions for the high bands probably exist when the solar
flux is very high, but the geomagnetic field is very stable.  This
would be when the K index is below 3, preferably 0 or 1, and the A
index is in the single digits.  It is a sad fact that the type of
activity that produces a densely charged ionosphere often produces
flares and coronal holes, which tend to increase absorption.

What is generally bad for HF is not the same for 6 meters.  While HF
experienced high absorption, 6 meter operators were working DX.  A
number of reports were received this week from Midwest hams who
worked South America and the Caribbean on 6 meters.

There is a really bright future for HF though, coming up this
weekend.  As of Thursday evening, the predicted solar flux for
Friday through Sunday is 242, 245 and 245, and the planetary A index
forecast is for 18, 10 and 8.  So while the solar flux should rise
to high levels, the geomagnetic indices should drop.  What could be
better?  Look for great conditions for the Japan International DX
Contest this weekend.

Beyond the weekend look for a declining solar flux, but it should
only bottom out around 160 for November 18-21, then rise to 170
around Thanksgiving, then drop to 145 at the end of the month.
Disturbed geomagnetic days include November 19-20 and 24, and the
few days following December 4.

NASA has a web site devoted to observation of the Leonids meteor
shower, which is coming November 17-18.  Check it out at
http://science.nasa.gov/newhome/headlines/ast11nov99_1.htm.  This
year's shower is predicted to be the biggest in decades.  Another
web site to check is http://solar.uleth.ca/sunnow/, which gives a
real time image of the sun from a solar telescope at California's
Sacramento Peak.

Sunspot numbers for November 4 through 10 were 108, 153, 188, 185,
232, 288 and 343 with a mean of 213.9.  10.7 cm flux was 147.5,
160.5, 150, 173.9, 191.9, 229.9 and 248.5, with a mean of 186, and
estimated planetary A indices were 5, 4, 7, 24, 33, 25 and 12, with
a mean of 15.7.

Path projections this weekend are for the Japan International Phone
DX Contest.  All of these paths are from United States locations to
Japan.

From Atlanta, 80 meters 0700-1300z, 40 meters 0600-1330z, 20 meters
open all hours, best 1230-1330z, weakest 1730-1830z and 2030z, 15
meters 2100-0130z, 10 meters 2200-2330z.

From Dallas, 80 meters 0700-1400z, 40 meters 0700-1400z, 20 meters
2100-0430z, 0630-0730z and 1030-1700z, 15 meters 2100-0230z, 10
meters 2130-0030z.

From Los Angeles, 80 meters 0730-1530z, 40 meters 0700-1600z, 20
meters 0200-0630z and 1500-1700z, 15 meters 2100-0330z, 10 meters
2130-0130z.

From San Francisco, 80 meters 0730-1600z, 40 meters 0600-1630z, 20
meters 1530-1630z and 2030-0600z, 15 meters 2100-0330z, 10 meters
2200-0200z.

From Seattle, 80 meters 0730-1630z, 40 meters 0600-1730z, 20 meters
2000-0630z and 1600-1630z, 15 meters 2130-0300z, 10 meters
2200-0130z.

From Alaska, 80 meters 0700-2030z, 40 meters 0530-2130z, 20 meters
2000-1130z, 15 meters 2130-0530z, 10 meters 2200-0400z.

From Hawaii, 80 meters 0730-1730z, 40 meters 0630-1830z, 20 meters
2000-1500 or possibly 1700z, 15 meters 2000-1230z, 10 meters
2100-0700z.

From the center of the contiguous 48 states (in Kansas), 80 meters
0700-1430z, 40 meters 0600-1530z, 20 meters 2030-0330z and
0600-0900z, 15 meters 2100-0230z, 10 meters 2200-0000z.

From Boston, 80 meters 0700-1300z, 40 meters 0600-1300z, 20 meters
2030-1130z, 15 meters 2130-0130z, 10 meters 2200-2230z.

From New York City, 80 meters 0700-1300z, 40 meters 0600-1400z, 20
meters 2030-1000z, 15 meters 2130-0030z, 10 meters around 2200z.

From Philadelphia, 80 meters 0700-1300z, 40 meters 0600-1430z, 20
meters 2030-0930z, 15 meters 2130-0030z, 10 meters 2200z.

From Cleveland, 80 meters 0700-1330z, 40 meters 0600-1330z, 20
meters 2030-0900z, 15 meters 2100-0100z, 10 meters 2200- 2300z.

From Chicago, 80 meters 0700-1400z, 40 meters 0600-1400z, 20 meters
2030-0400z and 0630-0900z, 15 meters 2100-0130z, 10 meters
2200-2330z.

From Omaha, 80 meters 0700-1430z, 40 meters 0600-1530z, 20 meters
1430-1600z, 2030-0300z and 0630-0830z, 15 meters 2100-0200z, 10
meters 2200-0000z.

From Salt Lake City, 80 meters 0730-1530z, 40 meters 0600-1630z, 20
meters 1430-1700z and 2030-0700z, 15 meters 2100-0300z, 10 meters
2200-0100z.

From Denver, 80 meters 0700-1500z, 40 meters 0600-1600z, 20 meters
1400-1700z and 2100-0300z, 15 meters 2100-0300z, 10 meters
2200-0030z.
NNNN
/EX