HF News
I hate to start the report on a negative note, but we are about to experience unsettled geomagnetic conditions over the next few days.
The culprit is a large coronal hole on the Sun, which rotated into an Earth-facing position on Thursday the 14th. This large coronal hole, an area with open magnetic field lines, has already been responsible for an increase in the solar wind speed to more than 420 km per second and we can expect it to get worse as we enter the weekend. The hole actually spans the solar equator so is ideally placed to create maximum disruption to Earth.
If the Bz interplanetary magnetic field swings south we could see the Kp index rise and MUFs decline. If this does happen expect poor conditions until Sunday or Monday at the earliest.
Meanwhile, the solar flux index has declined to hit 103 on Thursday, which starts to put us in a difficult spot. Usually, we say that an SFI of 100 or more is needed for 10m to open up. So it may be that you’ll need to move lower in frequency for reliable HF openings.
DX to be worked next week includes 3B9IDX, Rodriques Island, T31TTT Kanton Island, the last few days of XT2AW Burkina Faso, and FO/F6BCW in French Polynesia.
Next week, NOAA predicts that the solar flux index could rise to be in the range 120-130, which put us back in the fun zone.Unfortunately, and for the reasons mentioned earlier, we can expect to see a Kp index of five this weekend, but it will eventually decline to perhaps two or three as the week progresses.
VHF and Up
The background pattern of unsettled weather remains with us for a while over the UK as a whole, but subtle changes from a cold northerly to a warmer southerly will bring higher temperatures back again.
To end the previous week, the cold northerly has brought some heavy showers with hail and thunder in places and the GHz bands will have seen some rain scatter opportunities. The transition to a more southerly origin of the air will be taking place over this weekend and although high pressure develops later in the week, we may have to wait until after mid-week for any chance of Tropo.
The next few weeks encompass a couple of minor meteor showers, the Tau Herculids and daytime Arietids to add to the random background input. There should be something to interest those looking for meteor scatter activity and of course it all contributes to the ‘fuel’ for Sporadic-E, which is largely comprised of meteor ionisation.
The solar activity has recently been offering a few minor enhancements of the Kp index, but no great results on the aurora front.
Sporadic-E has been producing results on 6m digital modes where there have been brief openings to VK, XT, DU2 and the USA for those lucky enough to catch them. The usual technique of checking during the two main activity windows of mid-morning and late afternoon should improve your chances.
If you get an opportunity to look at the jet stream patterns then it can be worthwhile trying paths that cross these since it’s believed they are good sources of atmospheric gravity waves that can reach the E region to aid the production of Sporadic-E.
EME now, and with maximum declination (longest moon windows) now almost coinciding with perigee (lowest path loss), conditions are at their best for the Northern hemisphere. Moon declination is positive, reaching maximum on Monday 18th. Path losses are at their lowest as we reach perigee on the 17th. 144 MHz sky temperature is low all week except for Saturday the 16th when the Sun and Moon are close in the sky.