QST de W1AW
Propagation Forecast Bulletin 26 ARLP026
From Tad Cook, K7VVV
Seattle, WA June 27, 1997
To all radio amateurs
SB PROP ARL ARLP026
ARLP026 Propagation de K7VVV
Conditions are still very quiet. Solar flux hovers around 70, and no change is forecast for the next few weeks. Last week's average sunspot numbers were down about 12 points from the previous week, average solar flux was down about a point, and the average A index of geomagnetic activity was up a little over two points. While solar activity may seem depressing, at least the geomagnetic activity is stable, indicated by low K and A indices. Probably the best day this past week in terms of low geomagnetic activity was June 21, when the K index was zero for most of the day.
A few years ago, Scott Craig, WA4TTK, wrote a PC freeware program for plotting solar activity. This software has been offered in the past to readers of this bulletin. Scott now has version 3.01 available. It is a 32-bit program for Win95, with new updates for MS DOS and Windows 3.1 as well.
The really interesting and useful new feature in v3.01 is the ability to automatically update the solar flux and sunspot number database when it scans new propagation bulletins. It pulls the solar data from the bottom of this bulletin and updates the database automatically. Get it from Scott's homepage on the web at: http://edge.net/~scraig/.
For any old bulletins to fill gaps in data, check on the ARRL website at: www.arrl.org/w1aw/prop/1997-index.html.
Sunspot Numbers for June 19 through 25 were 16, 23, 11, 15, 14, 14 and 34 with a mean of 18.1. 10.7 cm flux was 70.1, 70.2, 67.6, 69.5, 69, 69.9 and 71.7, with a mean of 69.7, and estimated planetary A indices were 10, 5, 3, 9, 7, 6, and 8, with a mean of 6.9.
Conditions shouldn't be bad for Field Day this weekend. Don't forget sporadic E skip on 10 meters. Here are several domestic path projections useful for this operating event.
From the East Coast to the West Coast, check 80 meters from 0230 to 1030z, peaking around 0530 to 0930z. 40 meters should be good from 0030 to 1300z, and peak from 0400 to 1030z. Check 20 meters from 1500 to 0500z, peaking after 0200z.
From the East Cost to the Central U.S. check 80 meters from 2230 to 1300z, with excellent signals around 0930z. 40 meters looks good around the clock, peaking from 0200 to 1100z. 20 meters looks best over this short path around 2100 to 2200z and perhaps 0230 to 0330z.
From the West Coast to the Central U.S. 80 meters looks good from 0215 to 1230z, peaking from 0500 to 1030z. 40 meters is open all the time, but best conditions are from 0330 to 1100z. 20 meters is best around 2200 to 0830z and 1200 to 1630z. There may be some 15 meter openings from 1600 to 0600z, but this may prove difficult.
From the Pacific Northwest to the Southeastern states, 80 meters looks good from 0300 to 1100z, and 40 meters from 0030 to 1330z. 20 meters looks marginal, but may open from 1630 to 0600z.