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HF News
Last week was pretty unremarkable as far as the Sun goes, but it looks like that is about to change.
On Thursday the 30th, the last seven days had been characterised by reasonably settled geomagnetic conditions, with a maximum Kp index of 3.67 and a solar flux index that fell from 205 on the 24th to the 170s by the 30th. There had been only four M-class solar flares and no X-class events.
But over the next few days, things could change. Two large coronal holes near the Sun’s equator threaten to upset the quiet conditions. As the solar material flows out it could cause the Kp index to rise, perhaps to Kp=4, with reduced MUFs and noisy conditions. But this will depend upon its associated Bz or interplanetary magnetic field.
If it is south pointing it will couple more easily with the Earth’s magnetic field, allowing plasma to flow in and the Kp index will rise. However, if it is north-pointing we may see very little effect at all.
So keep an eye on Solarham.com for real-time updates and look for increased solar wind speed as the main indicator of the approaching solar material.
If the Bz does point south we may expect unsettled conditions and possible aurora on Friday, January 31st and Saturday, February 1st, possibly stretching to Sunday the 2nd.
Meanwhile, three sunspot groups are rotating into an Earth-facing position in the Northern hemisphere on the Eastern side of the Sun. We have already seen an M-class flare from one of them.
These could boost the SFI, but could be a source of solar flares and coronal mass ejections over the coming week.
Strangely, NOAA does not seem to think they will as its predicted SFI over the next seven days is in the range 150s-160s. It does agree with our prediction of unsettled geomagnetic conditions though with a projected Kp index of five on the 2nd, falling to four over the following three days.
We will just have to wait and see.
Meanwhile, MUFs over a 3,000km path are still exceeding 28MHz from around 0830hrs to 1600hrs UTC. As the month moves on we can expect the amount of
daylight to increase, so this period may be extended.
Make the most of 160m and 80m as the optimum time for these bands has now passed.
VHF and up
The tail end of the previous week saw a few weak weather features as lows and a front brushed past, but from this first weekend, the 1st and 2nd, there will be a trend to higher pressure, which will offer up some Tropo opportunities at times during the coming week.
There is a chance of the occasional decaying front drifting down the country, but for most of the next week it’ll be a Tropo story, if anything.
50MHz has been quiet again as we await the return of maybe the last Spring equinox-style propagation of this cycle around mid-March.
Meteor scatter is once again mostly down to random activity although there is one minor shower, Capricornids/Sagittariids, which will peak on Saturday February 1st.
Rain scatter may be somewhat rarer due to the mainly high-pressure pattern.
Some auroral propagation is not without hope in view of the large coronal hole, which crossed the Sun last week. Keep a lookout for high Kp values and an ear open for watery signals on the LF bands as a good sign of potential activity on the higher bands.
Moon declination goes positive again this coming Sunday, the 2nd, and with perigee late on Saturday the 1st, this means that the upcoming week will be good for EME, especially on the GHz bands, if you have a clear view of the horizon. 144MHz sky noise is low, rising to moderate next weekend.
One final note, there are some access problems with the data feeds for the Propquest website; hopefully, these are temporary and may have fixed themselves by the time you hear this. The other data plots such as jet stream charts should continue to update so there is plenty to look at on the other pages.