Propagation News – 23 May 2021
We had another wild week with sporadic E bringing most of the excitement on the upper HF bands. Transatlantic multi-hop Es brought USA contacts to many UK stations, mainly on CW and FT8, although there were some SSB ones too. The sporadic E action is always welcome on the HF bands during this time of year as activity can be otherwise low. So, make the most of the Es this month as it can tail off as the season goes on.
The Sun refused to play ball last week with the solar flux index firmly in the mid-70s with few sunspots. Region 2824 is now on the Sun’s visible disk. However, it is not too complex and should only be a threat for an isolated C-Flare in the short term.
Geomagnetic conditions have been generally relatively settled with a maximum Kp index of three. On Thursday, it rose to five due to the solar wind from a coronal hole. The solar wind speed increased to 400km/s and the Bz went sharply south.
Next week, NOAA predicts the solar flux index will remain in the mid-70s. Geomagnetic conditions are predicted to remain quiet with a maximum Kp index of two. This could all change though if we have any solar flare activity with associated CMEs.
Daytime F2-layer maximum usable frequencies are struggling to get above 18MHz, although this is compensated by the extensive sporadic E openings. Hopefully, these will continue to bring inter-G action, and short-skip from Europe and even further afield.
VHF and up
Struggling temperatures and deep lows crossing the country mean that the next week is likely to see a continuation of the unsettled conditions with showers or spells of rain, together with quite windy conditions at times. It also points the mode of choice towards rain scatter again.
However, there are hints of a change coming after midweek with high pressure moving into the western side of Britain, but leaving a chilly northerly over much of the country, perhaps a few showers. The high does not look particularly strong for tropo since it forms in cold air, to begin with anyway.
That leaves the sporadic E prospects to discuss and with the jet stream picture remaining favourable, there should be opportunities, but it’s probably optimistic to expect it to be as good as the week just past, where the US was workable on CW with a modest antenna at times.
The Moon declination is negative again, so shorter visibility windows and lower peak Moon elevations are the order of the day. This is compensated by path losses falling to a minimum as we reach perigee on Wednesday.
No significant meteor showers this week so continue to be active around dawn for the best random meteors.
Category: GB2RS Propagation News
