Propagation News – 16 February 2020

| February 14, 2020

Last week saw reasonably-settled HF conditions after the effects of a geomagnetic disturbance passed. But the Sun remained spotless again with a solar flux index of about 70-72 all week.

Wednesday’s 80m Club Championship contest left many amateurs feeling disappointed and with fairly empty logs after the critical frequency let them down.

At the start of the contest the f0F2 as measured at RAL in Chilton was 3.5MHz, but it then declined before finishing at 3.45MHz at 21.30hrs. As a result, long skip was the order of the day with the highest scorers being in Scotland, the Netherlands, Germany and Sweden.

With a few exceptions, there were few inter-G contacts as the high-angle signals were just not being returned by the ionosphere. Hopefully, this will improve over the next few months as the series continues and the evening critical frequency or f0F2 rises.

Barring any dramatic changes, NOAA has the solar flux index at 71 this coming week. A large coronal hole should become Earth-facing on Friday, the 14th, which means we may see its associated high speed solar wind impact the Earth around Sunday or Monday the 16th/17th. This could see the Kp index rise to four with characteristic disturbed conditions after a potential initial positive phase.

There are some DX nuggets to be had this week. Mike TI7/G3WPH and John TI7/G4IRN are both active in Costa Rica until 17 February. They have already been spotted on 160m and 40m, and should be taking part in this weekend’s ARRL International DX Contest. See for prediction details to Costa Rica.

VHF and up

Next week’s weather is likely to continue the unsettled theme, so more strong winds at times and little real chance of significant tropo paying a visit. There may just be a brief weak ridge close to southern England midweek, but not looking too useful for developing the inversions needed for tropo.

In propagation terms, that leaves us with some potential for rain scatter as active fronts and showers bring useful scatter points regions for the GHz fraternity.

The shower examples may be quite a challenge since the rate of movement can be quite high in such windy weather; imagine trying to follow a target moving at 40mph! Radar displays are your friend here and can make a big difference to the outcomes.

Moon declination reaches its minimum for the lunar month on Wednesday, with the Moon appearing above the horizon for seven hours and reaching just 13 degrees elevation. Path losses are rising all week and 144 MHz sky noise is very high, peaking at around 3000 Kelvin on Tuesday.

Keep looking for random meteor scatter QSOs around dawn when the Earth is rotating towards the main meteor flux to keep the VHF DX coming.

Category: GB2RS Propagation News