ARLP016 Propagation de K7VVV:
April 17, 1998

ZCZC AP16
QST de W1AW
Propagation Forecast Bulletin 16 ARLP016
From Tad Cook, K7VVV
Seattle, WA April 17, 1998
To all radio amateurs

SB PROP ARL ARLP016
ARLP016 Propagation de K7VVV

Solar activity has remained fairly high over the past week. Average sunspot numbers were up almost 30 points, and average solar flux was about that same, at 122. Average solar flux for the previous 90 days went up another two points from 102 to 104, and flux values were above these levels on every day, indicating a good upward trend.

April 9 saw a new high in sunspot number for the current cycle, when it reached 192. The sunspot number has not been that high since October 26, 1992, when it was 193.

Solar flux for this weekend, April 17-19 is predicted to be 100, 100 and 95. Through the end of the month look for solar flux to bounce around between 95 and 108, then rise above 110 after May 2, peaking around 125 about a week later. Geomagnetic indices may be unsettled today and also around April 24 and 25.

Higher solar activity has extended long distance 20 meter openings well into the evening. From the author's home in Seattle, New Zealand and Australia are strong on 20 meters even as late as midnight. Look for openings on higher frequencies as well, although on 10 and 12 meters the openings tend to be over north- south paths.

Next week this bulletin will be written by KH6BZF while the author is on Maui. Listen for us at KH6X until April 25.

Sunspot Numbers for April 9 through 15 were 192, 145, 132, 111, 82, 83 and 79 with a mean of 117.7. 10.7 cm flux was 139.7, 129.7, 128.3, 117, 114.8, 111.9 and 112.7, with a mean of 122, and estimated planetary A indices were 9, 11, 12, 9, 5, 8, and 4, with a mean of 8.3.

Here are some path projections to Hawaii from the continental United States;

• From the west coast try 80 meters from 0400-1430z, 40 from 0230- 1630z, 30 from 0100-1030z and 1230-1800z, 20 from 1630-0800z, 17 from 1830-0500z, 15 on some days from 1900-0300z and on rare days 10 may be open from 2000-0000z.
• From the midwest try 80 from 0430-1300z, 40 from 0330-1400z, 30 from 0230-1500z, 20 from 1400-1445z and 1600-0800z with better conditions later in the period, 17 from 1600-0630z, 15 from 1730-0400z and 10 on some days from 1900-0300z.
• From the east coast try 80 from 0430-1100z, 40 from 0400-1200z, 30 from 0230-0730z and 0930-1300z, 20 around 1400z, 1600-1730z and 2300-0600z. Check 17 from 1630-0400z and 15 from 1900-2330z.