Propagation News – 19 January 2020

| January 17, 2020

We had another pretty uneventful week with zero sunspots, but no major geomagnetic disturbances. The K-index rose to three on Thursday morning due to the effects of the solar wind, but the ionosphere was otherwise calm geomagnetically.

We said last week that there had been some winter sporadic E, which had livened up 10 metres. We also said there had been no SSB activity of note on the band and was promptly corrected by Tony, M0IQD who sent a copy of his log. This showed that he made more than 15 SSB contacts on 8 January, including Norway, Sweden, Poland, Germany and even VO1FOG in Newfoundland. Keep an eye open around 28.450 to 28.495MHz for SSB openings. He also suggested that the Facebook group 10 Metre UK Net was a useful tool for 10m operators. We’re only too happy to pass that information on.

Next week NOAA predicts the solar flux index will be in the range 70-72, reflecting the current state of the solar cycle. It also predicts quiet geomagnetic conditions all week, so the ionosphere should be settled and showing seasonal norms in terms of propagation.

According to Propquest, daytime critical frequencies as measured by the Chilton digisonde are generally in the range 4.1 to 5.3MHz. This suggests that 80m remains best for inter-G contacts, with 40m being restricted to longer paths such as G to GM. Night-time critical frequencies are generally around 3.1 to 3.6 MHz, so 80m propagation may be marginal over shorter distances, but better over 500km or more.

Daytime F2 layer openings are generally up to 18MHz, with the 20 metre band being more reliable.

Weather charts show that the jet stream will remain strong over the UK and Europe next week, which may be an indicator for winter sporadic E, although the season may be ending—more of this in the VHF section.

VHF and up

High pressure has started to reassert itself over southern Britain and improved tropo conditions will probably kick in from today into early next week. Paths into the continent and south past Portugal towards the Canaries might be worth a look, in view of recent performances. This positive tropo pattern could hold into midweek, but thereafter the models show a collapse of the high back towards the Azores, allowing room for a colder north-westerly to bring stronger winds and a risk of some wintry weather across eastern areas. But other models confine the cold outbreak to the northern half of the UK only.

There is always scope for some winter sporadic E and the jet stream pattern may favour paths into western Europe and the western Mediterranean, particularly for digital modes like FT8, but it could also be worth checking for CW and SSB on 10m too.

The cold northwesterly with its wintry showers may excite the GHz fraternity towards the latter part of next week as heavy showers move down the North Sea and Irish Sea, bringing some rain scatter propagation. The good thing about winter rain scatter is that the showers are not diurnal like in summer and usually maintain activity throughout the day and night.

Moon declination is negative and reaching a minimum on Thursday. Path losses continue to rise all week, and the very high 144MHz sky noise midweek means it’s a poor week for EME.

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

Category: GB2RS Propagation News