sabato 25 gennaio 2020

Propagation News – 26 January 2020

This week saw a decline in sporadic E conditions on 10m. This may be due to a repositioning of the jet stream or just the end of the winter sporadic E season, but more of that in the VHF section.
On the face of it, last week saw the Sun behaving itself, with zero sunspots. But look a little closer and it has actually been quite active. Two solar events were launched off the Sun’s surface, one on Sunday, the 19th, which was preceded by an X-ray solar flare, the other from a coronal hole on Monday, the 21st. There was a slight increase in the solar wind at times this week due to the coronal hole’s solar wind stream. This pushed the Kp index to three.

Next week, NOAA predicts the solar flux index will remain around 72, with mainly settled geomagnetic conditions. The Kp index is predicted to remain around two, at least until 1 February when an unsettled region of the Sun rotates back into view.

The most interesting propagation this week has been on the low bands, notably Top Band and 80 metres. Derek, G3RAU reports on the CDXC reflector that he worked Mexico on 80m at 0900UTC, while Chris, G3SJJ worked NA5G in Louisiana on 160m at 0745UTC. Victor, G3JNB reports working JT5DX in Mongolia on 80m in the late evening. The JT5 station has also been active on 160 metres.



This really is an optimum time of year for low band DXing, so keep an eye on 160, 80 and 40 metres, especially around dawn for DX from the west. The DX net around 3.795MHz every morning is always a good test of your station’s 80m DX capabilities.

VHF and up:
It’s goodbye to the high pressure as we go through this weekend and the Atlantic weather systems start to move in from the west. This will set up a very unsettled period of weather again during most of the week with strong winds, especially in the north, but also in southern areas at times.

As for propagation, there should be some GHz bands rain scatter options as squally fronts cross the country, and from scattered showers in the unstable westerly flow which follows the cold fronts.

Although high pressure remains over the southern half of the continent, it will be well out of reach from most of the UK and tropo is unlikely to be a feature of propagation this week.

It’s always just possible for out of season sporadic E, and the jet stream over the UK is likely to strengthen again next week. If this were high summer it would be a very positive steer, but in mid-winter it’s not a good prospect, except perhaps for paths to Scandinavia and the Baltic if you are really lucky.

Moon declination is rising this week, going positive on Thursday. Apogee is on Thursday, so it is not a great week for EME due to high path losses. 144MHz sky noise is low.

There are no major meteor showers this week so continue to look for random QSOs in the early morning around dawn. (rsgb.org)