Propagation News – 23 October 2022
We had another great week of HF propagation, helped no doubt by a very low geomagnetic Kp index meaning the ionosphere remained settled.
Despite the solar flux index declining to 113 by Thursday, 10m has been highly active with openings every day. We have had good daily 10m openings, even out as far as the west coast of USA for well-equipped stations.
Next week NOAA predicts that the solar flux index will continue to remain in the 110-120 range. This is not extreme but would be enough for good propagation on all of the upper HF bands if we don’t have any geomagnetic disturbances.
A rather large coronal hole is rotating into view and should become Earth-facing on the 21st. This is fairly low on the Sun’s face so might not impact us as badly as a coronal hole on the solar equator would. But, nevertheless, its size suggests that any disturbance might be long lived. If so, expect its plasma to hit Earth late Saturday or Sunday.
NOAA also predicts that the Kp index will rise on Wednesday 26 October with the index rising to five. Quite what will cause this is unclear, although it could be the return of an active region that took the Kp index to six 27 days ago.
Once that clears, we may expect good conditions on 10m to hopefully continue, so make the most of them.
VHF and up
The current transition to changeable autumnal conditions is fully complete and proving very difficult to shift. This means that the breezy unsettled weather with low-pressure systems pushing fronts across the country will continue during the period.
This may produce some rain scatter options, although it’s not a big ‘shout-out’ compared to the intense thunderstorms of high summer.
There will be some high pressure nearby over the continent, but it’s not likely to be a big Tropo player and remains largely out of reach from the UK.
One minor meteor shower, the Leonis Minorids peaks on Tuesday 24 October, but the ZHR is low.
Aurora could crop up on occasions during the coming week and, after recent activity levels on 6m, there is still a chance of Sporadic-E. This recent activity just shows that we should probably learn to regard it as an option, especially on FT8, even in the nominal ‘close season’ for Es.
Moon declination goes negative today, Sunday, so Moon windows continue to shorten as the week progresses. With perigee next Saturday, path losses will fall throughout the week. 144MHz sky noise starts low, but there is a partial solar eclipse on Tuesday 25 October so that day will be an EME washout. After the eclipse, the noise rises slowly from 380K to around 3000K next Saturday, making it a noisy week for EME.
Category: GB2RS Propagation News
