RSGB
GB2RS News Team
January 24, 2025
This week, ending today the 26 January, has looked a lot like a repeat performance of two weeks ago. The majority of the sunspots are in the western hemisphere with very few in the eastern side. This means that
the solar flux index could drop over the coming week unless there are sunspots ready to rotate into view to replace those being lost.
A look at the STEREO Ahead spacecraft imagery suggests that there are indeed sunspots over the Eastern limb, so all may not be lost.
Overall, the Sun has been fairly quiet. There were no X-class flares and only five M-class flares from the 19 to the 23 January. The Kp index has also been relatively low, only peaking at four for one three-hour period on the 20 January.
As a result, with the solar flux index in the 200s, HF conditions have been quite good. The maximum usable frequency over a 3,000km path has been consistently over 28MHz, from around 0830 to 1600UTC. However, the
20, 17, 15 and 12m bands, seem to be carrying most of the DX at the moment.
Next week, NOAA predicts that the solar flux index will remain in the mid-200s. Geomagnetic conditions are also predicted to be good until the end of the month, but a Kp index of 5 is forecast for the 31 January,
and this could last for a few days.
So, we urge you to make the most of the conditions now, before geomagnetic storming, if it occurs, makes a mess of HF as we enter February.
VHF and up :
The weather pattern is being driven by a very strong winter jet stream across the Atlantic Ocean. This gives scope for rapid development of deep lows and consequent gales and damaging winds.
On Friday 24 January, the first big storm hit the northwest of Britain. We may find that the next low in the series is heading for southern Britain tomorrow, the 27 January.
This all makes tropo unlikely for much of the week ahead since it stays unsettled through most of the period, but with the smallest hint of higher pressure trying to return from Thursday.
Rain scatter will probably be worth some consideration on the GHz bands while meteor scatter remains driven by random activity rather than any major showers.
There have been further aurora alerts over the last week and it’s always worth keeping the Kp index in view to monitor any possible chances for aurora. High figures, above a Kp index of 4, are a good trigger point to get interested.
Moon declination reaches minimum in the northern hemisphere today, the 26 January, when Moon windows are at their shortest and peak Moon elevation is at its lowest.
Path losses are now falling as we passed apogee on Tuesday the 21 January. 144MHz sky noise is high, reaching over 3,000 Kelvin today, the 26 January, before dropping to moderate until Wednesday when the Moon and Sun are very close in the sky for the whole Moon pass. After this, it drops to low for the rest of the week.
(Mike Terry, UK/BDXC)
