HF News
Last week I said there were no coronal holes to threaten HF propagation. But while I was right at the time of writing, guess what appeared shortly after?
Coronal holes can appear at any time, which is why I recommend going to solarham.com for daily updates.
This week another coronal hole has appeared and this one really does look like it could threaten Earth. This, coupled with coronal mass ejections, means this weekend could see the Kp index rise and MUFs fall.
On a brighter note, the Kp index has been very low this past week, mostly below two, with the result that HF propagation has been very good. Top DX being worked includes RI1FJL on Franz Josef Land in the Arctic Circle, which has been loud on many bands, including up to and including 10 and 12 metres.
Other DX to be worked next week include V5/HB9BFM (Namibia), J38DX and J38LD (Grenada) and P29YY (Papua New Guinea).
A quick check of the NCDXF beacon chain revealed very good propagation on 14MHz and 21MHz, including reception of the CS3B (Madeira), RR90 (Siberia), 4S7B (Sri Lanka), 4X6TU (Israel), and 4U1UN (New York) beacons.
So it looks like we are starting to leave the summer doldrums and entering better autumnal HF conditions.
Next week NOAA predicts that the SFI will be around 120, falling to 90 as the week progresses. After the potential for geomagnetic disruption this weekend the forecast is good with a Kp of around two.
VHF and up
The weather has properly turned into autumn style with lows bringing periods of rain or showers and quite windy conditions at times. The coming week will turn out in similar fashion and means that we won’t be dealing with much, if any, Tropo for VHF and the main weather-dependent mode will be rain scatter for the GHz band operators.
The chances of aurora will need to show a Kp index above Kp=5 to be of much interest, and probably a bit more for southern areas. The prospects for meteor scatter are likely to be reduced to random activity which tends to give better results in the early morning hours before dawn.
Lastly, we are coming to the close of the Sporadic-E season and with probably a week or so to play out, any openings will be few and far between. Try checking during the main operating windows of mid-morning and again late afternoon, although as a back-up, consider the middle of the day, since towards the edges of the season the traditional timings are less reliable.
For EME operators, Moon declination goes positive again on Saturday the 29th, with increasing peak elevation and lengthening Moon windows. Path losses are falling all week towards perigee on September 6th. 144 MHz sky noise is low, increasing to medium by next Friday.