Propagation News – 23 June 2019

| June 21, 2019

The week was dominated by thunderstorms and rain. While not strictly HF propagation-related, this did cause havoc on the lower bands, with frequent static crashes. This was particularly noticeable in Thursday’s RSGB 80m Club Championship CW contest, where storms over the low countries made the contest hard-going.

Other than that the week was once again marked by a lack of sunspots, but more settled geomagnetic conditions. The solar flux index was pegged at 67-68, with the Kp index fluctuating between one and two. F-layer propagation has generally seen maximum useable frequencies over a 3,000km path around 14-18MHz, although frequent sporadic E openings have seen this boosted to 28MHz and higher on short-skip paths.

As an example, the five watt IW3FZQ/B beacon on 28.227MHz in Monselice, Italy and ED4YAK/B on 28.251MHz in Henares, Spain were both booming in on Thursday at 0900UTC, with no other CW or SSB signals on the band.

Next week NOAA has the solar flux index remaining at 68-69, with generally calm geomagnetic conditions other than around Monday, the 24th, to Wednesday, the 26th, when it predicts the Kp index could rise to four.

At the time of writing most coronal hole activity was around the solar poles, which shouldn’t threaten the Earth.

VHF and up

The weekend starts with a weak high transiting across the British Isles, which could give some tropo enhancements for southern stations, while the north remains closer to the old low and its showery weather type. Some models retain a tendency for higher pressure in the south and further possible tropo.

The fact that showery weather is not far away and continues to put in appearances during the week ahead, means that rain scatter should again be an option for GHz band enthusiasts, especially for northern and western areas.

There have been a few active days recently for sporadic E and, in a jet stream sense, the coming week offers some useful directions for sporadic E paths. South to Spain and north-east into Scandinavia should be favoured. Additionally there is a broad upper ridge pattern over eastern Europe and this can produce good openings in the high summer. Remember the peak periods for sporadic E are late morning and late afternoon or early evening.

This Sunday, the Moon is at apogee with declination rising and going positive on Wednesday, so EME conditions will slowly improve as the week progresses, with falling path losses and lengthening Moon windows.

As mentioned last week, the Bootids meteor shower peaks on Thursday but no unusually high zenith hourly rate is predicted for 2019.

Category: GB2RS Propagation News