ARRL

ARRL Propagation Bulletin ARLP003 (2000)

SB PROP @ ARL $ARLP003
ARLP003 Propagation de K7VVV

ZCZC AP03
QST de W1AW  
Propagation Forecast Bulletin 3  ARLP003
From Tad Cook, K7VVV
Seattle, WA  January 21, 2000
To all radio amateurs 

SB PROP ARL ARLP003
ARLP003 Propagation de K7VVV

Solar flux was up, geomagnetic activity was down.  What could be
better for HF propagation?  Average solar flux this week was up 35
points, or over 20 percent, compared to the previous week.
Geomagnetic conditions were quiet, with A indices in the single
digits.  The most stable day was January 17, when the planetary A
index was 3 and the K index was 1 during five of the eight daily K
index reporting periods.  There also was a 3-hour period when the K
index was 0.

During periods of heightened geomagnetic activity the higher
latitudes always get hit worse.  When the bands are rough in the
lower or mid-latitudes, they often are unusable in places closer to
the poles, such as Alaska.  This is reflected in higher K and A
indices at higher latitudes.  But on January 17, the geomagnetic
indices measured in Alaska (referred to as the College index) were
actually lower than at lower latitudes, with five of the eight
periods showing a K index of 0, and two periods at 1.  The College A
index for that day (Monday) was 2.  It really doesn't get better
than that.

While one would expect the best of conditions with numbers such as
this, KK5CA in Texas wrote to say that he experienced a high noise
level over the weekend.  Since the numbers were so low, his
suspicion is that he and other hams in the area were hearing local
atmospheric noise stimulated by warm dry air and a steady wind.

Solar flux has been rising, and reached a short term peak on Sunday
with a 2000z measurement of 207.7 and a 2200z reading of 209.6.  It
has mostly been falling since, dropping to 178.6 on Wednesday and
170.7 on Thursday.  The outlook for this weekend is a continued
decline in flux, with values of 170, 165 and 160 for Friday through
Sunday.  The predicted planetary A indices for the same three days
are 12, 35 and 12.  Saturday's geomagnetic conditions could prove
interesting for this weekend's ARRL January VHF Sweepstakes.  The
reason for the predicted high geomagnetic activity is a class M3
solar flare on Tuesday, and an accompanying coronal mass ejection.
The energy from this event is predicted to have maximum effect on
Saturday, so expect poor HF radio conditions and possible aurora
enhanced VHF propagation.

After the weekend look for solar flux to decline to around 135 for
the period from January 27 through February 1, then rise above 150
around February 5 and peak again above 200 around February 11 and
12.  Expect unsettled geomagnetic conditions from January 27 through
the end of this month, with the worst conditions on January 27 and
28.

Sunspot numbers for January 13 through 19 were 218, 228, 268, 262,
227, 185 and 196 with a mean of 226.3.  10.7 cm flux was 202, 201.3,
210.7, 207.7, 196.4, 194.6 and 178.6, with a mean of 198.8, and
estimated planetary A indices were 10, 7, 5, 6, 3, 4 and 4, with a
mean of 5.6.

Path projections for this weekend are for Sunday from Dallas, Texas,
but the other ends of the paths are all taken from this week's ARRL
DX Bulletin, ARLD003.

To Rodriguez Island (3B9), 80 meters 2300-0200z, 40 meters 2300-
0230z, 30 meters 2200-0200z, 20 meters 2030-0100z, 17 meters
1530-0000z, 15 meters 1500-2300z, 12 meters 1430-2200z (17, 15 and
12 meters stronger toward the end of the periods), 10 meters
1500-1930z.

To Western Samoa (5W), 80 meters 0530-1400z, 40 meters 0430-1430z,
30 meters 0400-1530z, 20 meters 0300-1100z and 1330-1700z, 17 meters
around 1430z, 1600-1800z, 0100-0630z and 0800-0930z, 15 meters
1700-0300z, 12 meters 1700-0230z, 10 meters 1730-0130z.

To Barbados (8P), 80 meters 2300-1130z, best 0130-1000z, 40 meters
2200-1230z, best 0030-1000z, 30 meters open all hours, best
0030-1000z, weakest around 1230z and 1600-1830z, 20 meters
1300-0130z, 17 meters 1330-0000z, 15 meters 1400-2300z, 12 meters
1430-2200z, 10 meters 1530-2130z.

To Burundi (9U), 80 meters 2330-0500z, 40 meters 2230-0530z, 30
meters 2200-0530z, 20 meters 2030-0330z, 17 meters 1930- 0030z, 15
meters 1330-0000z, 12 meters 1400-2230z, 10 meters 1400-2130z.

To Andorra (C3), 80 meters 2230-0830z, 40 meters 2200-0900z, 30
meters 2130-1000z, 20 meters 1330-2200z, 17 meters 1400- 2000z, 15
meters 1430-1930z, 12 meters 1500-1830z, 10 meters 1600-1730z.

To Qatar (A7), 80 meters 2300-0400z, 40 meters 2230-0430z, 30 meters
2130-0500z, 20 meters 1930-0100z, 17 meters 1400- 2200z, 15 meters
1430-1700z, 12 meters 1530-1600z, 10 meters possibly 1530-1600z.

To Guernsey (GU), 80 meters 2300-0900z, 40 meters 2200-1030z, 30
meters 2100-0430z and 0600-1100z, 20 meters 1330-2100z, 17 meters
1430-2000z, 15 meters 1430-1800z, 12 meters 1530- 1700z, 10 meters
1630-1700z.

To Svalbard (JW), 80 meters 2300-1330z, strongest 0230-1000z, 40
meters 2130-1430z, 30 meters open all hours, best 0030-1230z,
weakest 1700-2000z, 20 meters 1400-0130z, 17 meters 1430-0030z, 15
meters 1700-2000z.

To Mariana Islands (KH0), 80 meters 0730-1400z, 40 meters 0700-
1500z, 30 meters 0630-1530z, 20 meters 0530-0630z, 0800- 1030z and
1400-1700z, 17 meters 1500-1630z and 2000-0300z, 15 meters
2030-0200z, 12 meters 2030-0030z, 10 meters 2100-0000z.

To Midway Islands (KH4), 80 meters 0430-1430z, 40 meters 0330-
1500z, 30 meters 0230-1630z, 20 meters 1730-1830z, 0030- 0630z and
0830-1000z, 17 meters 1830-0230z, 15 meters 1900-0130z, 12 meters
1930-0000z, 10 meters 1930-2330z.

To Brazil (PY), 80 meters 2330-1030z, 40 meters 2300-1100z, 30
meters 2230-1130z, 20 meters 1930-1000, 17 meters 1330-0230z, 15
meters 1300-0100z, 12 meters 1330-0030z, 10 meters 1400-0000z.

To Bangladesh (S2), 80 meters 0000-0030z, 40 meters 2300-0100z, 30
meters 1000-1500z and 2230-0200z, 20 meters 1400-2130z and
2330-0200z, 17 meters 1500-1630z, around 1830z and 0030-0100z.

To Eastern Kiribati (T32), 80 meters 0430-1530z, 40 meters 0300-
1500z, 30 meters 0200-1600z, 20 meters all hours, strongest
0430-1130z, weakest 1900-2230z, 17 meters 1600-1030z, 15 meters
1600-0330z, 12 meters 1630-0230z, 10 meters 1700-0200z.
NNNN
/EX