ZCZC AP11
QST de W1AW
Propagation Forecast Bulletin 11 ARLP011
From Tad Cook, K7VVV
Seattle, WA March 15, 2002
To all radio amateurs
SB PROP ARL ARLP011
ARLP011 Propagation de K7VVV
Next Wednesday is the vernal equinox, when the earth's position relative to the sun makes daylight equal over the northern and southern hemispheres. This is also a great time for HF DX. 12 and 10 meter conditions have been seasonally improving recently, but worldwide DX on these bands should decline after the equinox.
With equal sunlight in both hemispheres, neither experiences seasonally low MUFs, and neither has the problem of shorter band openings due to shorter days.
Solar flux and sunspot numbers have been flat, and there haven't been any big geomagnetic upsets this week. Average daily sunspot numbers were lower this week by 38, and solar flux was down nearly four points.
There was an M5 class solar flare on Thursday, but there is little chance of it affecting us. The current outlook is for solar flux staying about the same, but gradually rising over the next week to around 200. Currently the short term peak in activity is predicted for March 23-25.
Do you have propagation questions? Check K9LA's introduction to propagation at http://www.arrl.org/tis/info/k9la-prop.html. You may also write to the author of this bulletin at K7VVV@arrl.net.
Sunspot numbers for March 7 through 13 were 152, 133, 107, 114, 153, 139 and 154 with a mean of 136. 10.7 cm flux was 179.7, 176.8, 184, 179.3, 182.3, 178.4 and 184.3, with a mean of 180.7, and estimated planetary A indices were 10, 4, 5, 9, 9, 10 and 5 with a mean of 7.4.