Propagation News – 2 February 2020

| January 31, 2020

We had a new sunspot group last week, but don’t get too excited—region 2757 was from the old Cycle 24. We know this because it was close to the Sun’s equator and had the older magnetic configuration. As you read or hear this, the spot will be rotating out of view, off of the Sun’s eastern limb. A new plage region belonging to upcoming Cycle 25 also appeared high in latitude on the south-west limb, but didn’t amount to anything.

The Kp index peaked at three last week, possibly due to a minor geomagnetic storm triggered by a coronal mass ejection from sunspot group 2757. But otherwise, with the solar flux at 74 it was business as usual!

There was DX to be had. Andy, M0NKR reports working 7Z Saudi Arabia, 9W West Malaysia, HS0 Thailand and 4S7 Sri Lanka on 40 metres. He also reports working 8P Barbados, SO Western Sahara and FJ Saint Barthelemy on 17 metres.

SO1WS at the Sahrawi Amateur Radio Club has been very active on 17m, so keep an eye on the cluster for their current operating frequency.

Next week NOAA predicts that the solar flux index will be around 74, declining to 71 as sunspot 2757 disappears from the Earth-facing solar surface.

Geomagnetic conditions will be mainly settled with a maximum Kp index of three.

Expect to see openings up to the 18MHz band, with the 14MHz band being more reliable. The 21MHz band and higher are still not really playing ball, other than for FT8 contacts with Germany being spotted on 10 metres on Thursday.

VHF and up

The coming week’s weather has a continuing unsettled flavour, especially in the north, but with a hint of a brief ridge of high pressure passing across southern areas around mid-week. This means that it’s mostly GHz bands rain scatter on offer this weekend and into the beginning of next week, but again this appears to be mostly for northern parts of the country.

As the high builds later on Tuesday and through Wednesday we could see some tropo conditions extending to the south into the continent and across Biscay towards Spain, perhaps. This is a relatively brief period of high pressure and may not have enough time to build a strong inversion with moisture trapped beneath the inversion as required for a good lift.

The upper air charts for the coming week provide a significant chance of a strong jet stream in the upper atmosphere over or near the UK. This is the sort of pattern that can produce sporadic E in the summer season and may just tip the balance in winter if it goes in our favour. Take a look for digital mode activity on 10m for a “heads up.”

With Moon declination still rising, reaching maximum on Thursday, it’s a good week for EME. With just over a week to perigee, path losses are falling. 144MHz sky noise is highest on Wednesday, falling to its lowest on Saturday.

There’s a small meteor shower in progress, the Alpha-Centaurids, reaching its peak on Saturday. Due to the southern declination of its radiant, the best time is before dawn when the radiant lies highest above the horizon.

Category: GB2RS Propagation News