Propagation News – 26 November 2023

What a difference a week makes! Last week the solar flux index was at 118 but, by Thursday the 23 November, it had climbed up to 190 with the Sun’s surface covered in spots with up to nine groups showing.

The maximum useable frequency over a 3,000km path was estimated at more than 40MHz at times. This, coupled with a Kp index of around two to three, was quite good for HF.

But it isn’t all good news. There has been quite a bit of solar flare activity, and the promise of more to come. A significant eruption was recently observed beyond the northeast limb. This may result in a coronal mass ejection, but this will likely be directed away from Earth.

Active regions 3490 and 3492 remain the main regions of focus and are listed as the most likely to produce a noteworthy solar flare. The current flare threat stands at 55% for a moderate M-Flare and 10% for a strong X-Flare.

DX this week included 4W8X in Timor-Leste and Don, ??3B8/G3XTT in Mauritius.

The 10m band was good last week with the KQ2H repeater on 29.620MHz FM coming in strongly in the afternoon. There were plenty of SSB signals to work between 28.4 and  28.5MHz as well.

A scan from 28.200MHz to 28.300MHz around 2pm on the 23 November revealed plenty of beacons being received including IQ8CZ, IQ8BB and IZ8RVA in Italy; SV6DBG and SV2RSS in Greece; WW2BSA in New Jersey; K4PAR in Georgia; KA3JOE in Pennsylvania; and K5AB in Texas. All of these run less than 20W. For a full list of 10m beacons choose ‘Beacons and Repeaters’ from the ‘On the air’ tab on the RSGB website

Next week NOAA predicts that the solar flux index may decline to be in the range of 145 to 155. Geomagnetic conditions may be reasonably settled with a Kp index of two to three, although a coronal mass ejection or two could soon alter that!

So, make the most of the good HF conditions while you can, especially in this weekend’s CQ World Wide DX CW Contest.

VHF and up

Weather patterns are settling and, with the current cold north-westerly wind, there are signs of something useful for eastern areas in the form of potential rain-scatter from heavy showers running down the North Sea.

In the west, we have an area of high pressure with a chance of Tropo but, in cold low-level air near the surface, this may not be very reliable.

The chance of high pressure building is probably limited and we are already seeing a return to more changeable weather.

The bulk of the coming week will be controlled by low pressure with rain or showers.

So, we have the possibility of further rain scatter, but little chance of significant Tropo, except perhaps if high pressure tries to make a comeback in the north the following weekend.

The November Orionids meteor shower is making an appearance on the 28 November with a low Zenithal Hourly Rate, or ZHR, of three per hour for meteor scatter operators.

Keep checking for auroral modes and don’t forget that this can give LF bands a flutter to the signal, as was heard on 40m CW on Wednesday evening. In really strong events with a Kp index above, say, six then check the usual places for activity on the 6, 4 and 2m bands.

For EME operators, Moon declination is positive and rising to maximum on Wednesday the 29 November. Path losses are low to start the week but rising. 144MHz sky noise is low to moderate all week.

Category: GB2RS Propagation News