Propagation News – 23 November 2014

| November 21, 2014

As we predicted last week, sunspot region 2209 has been active, emitting a number of M- and C-class solar flares, although it is nowhere near as violent as it was on its last rotation. The solar flux index remained relatively high during the week, peaking at 170. The latest NOAA/USAF forecast predicts the solar flux index will be 170 on Monday 24 November and will then tail off towards 120 by the end of the week.

Geomagnetic conditions look to be reasonably quiet, especially after Tuesday, with the Ap index predicted to be a very low 2-4. This should bode well for reasonable HF conditions during next weekend’s CQ World Wide CW contest on the 29th and 30th.

As we head towards the winter solstice we are starting to see long path 40m openings to the west coast of the USA in the afternoon, just before sunset. VU4KV on the Andaman and Nicobar Islands has also been spotted on 40m around the same time. We are also starting to see 80m openings to the east coast of the USA before sunrise. Both bands are worth a second look at this time of year.

VHF and up propagation news

Meteorologist, Jim, G3YLA, says weather-related propagation factors are a bit thin on the ground once again. Thankfully, this week does offer an initial temporary period when a weak ridge of high pressure may provide a slight enhancement of VHF/UHF tropo conditions. This is just at the beginning of the week, but with low pressure nearby, it represents only a marginal, and certainly temporary, improvement. Towards the end of the week it seems likely that returning low pressure will put us right back to November’s typical flat conditions.

The more settled sun and low Ap index means little chance of auroras this week.

Last week’s Leonids meteor shower turned out to be much poorer than expected, and the Geminids are still three weeks away, but it’s still worth trying for random meteor activity in the early mornings especially on 50 and 70MHz.

For EME operators, the Moon gets to its lowest declination on Monday, meaning shortest moon availability, but is at perigee—the closest point—on Friday, meaning losses are lowest.

Despite the poor outlook on the VHF and microwave bands this week, there is always propagation by aircraft reflection and random meteors to experiment with.

Category: GB2RS Propagation News