In which I yell at clouds

Chances are, you’ve seen one of the hundred versions of the “old man yells at cloud” meme that features grandpa Abe Simpson. Changing the target slightly sets up what follows.

Hey, it’s like yelling at a cloud, only the F layer is a hundred times higher than a cloud – or more. The F layer pays just as much attention as the cloud does. Or less.

After the Geomagnetic storms we went through this week, there were many posts around the places I visit most online where people referred to storms along with either good or bad conditions and their accomplishments (like Every Blade of Grass, or Come and Make it as well as here). Some of us had both good and bad. Along the same line, the only accomplishments I’m actively “chasing” on the VHF six meter band are both in the category of “difficult to practically impossible.” The easier one is probably 6m DXCC (100 recognized countries worked and confirmed). I currently have 87 confirmed with another four “waiting for confirmation.” I’m closer to DXCC on 6m than any of the major awards. Easy or obvious one first, DXCC is more likely than Worked All States - WAS. 

WAS is practically impossible from my location. I’m pretty sure last November (‘24) was the closest I ever came to even hearing Alaska, and that was hearing other stations in the southeast calling the guy in Alaska. I saw him “spotted” on some of the sites online that report that, but never actually heard him. I was hoping for this year, but it hasn’t been good so far.

The hardest one, the FFMA (Fred Fish Memorial Award – the first person to achieve this award) is for working and confirming all 488 Maidenhead grids in the continental US. "Continental" means I don't need Alaska. I have 345 grids confirmed with another five that I’ve worked but can’t get confirmed. To be brutally honest, the FFMA is practically impossible from here, too. Unsurprisingly, when your goal is to reach every place  in the country, you're most likely to get everyone from the center of the country, and it turns out there has been one issued in Florida, in the northwestern most corner of the state. That's about 500 miles away - near Pensacola.

You’ll note that linked page refers to them as grid squares. They’re not. It’s a fun fact that these are two degrees in longitude by one degree in latitude, making them grid rectangles. I’ve never seen anyone anywhere refer to them as “grid rectangles.” 

Where these intersect with a meme about the F-layer of the ionosphere is that the F-layer is the key to long distance propagation in radio, especially 6m (50 to 54 MHz in the US). When conditions are good, the F-layer splits into two layers (F and F2), with F2 higher in altitude and allowing ever farther contacts.

As a good, general, Rule of Thumb (RoT), there are two things to watch in a propagation forecast, the Solar Flux Index (SFI), a measure of the strength of the constant radio signal (2.8 GHz) coming from the sun, and the K index, a measure of the geomagnetic field strength and stability. Both of these are given as a single number summary of many measurements in many places. A default page I always have open is the one I can look up “where you at?” when I hear someone I’m interested in. The current solar terrestrial indices are displayed in a dedicated box toward the top of the page, data from N0NBH.

The RoT for SFI is “the more the merrier.” There isn’t a handy RoT for K or the Planetary K index (Kp). Both too low and too high are bad, it’s just that what’s a good Kp depends on frequency and that’s different depending on what band you’re using. My experiences on 6m lead me to think a Kp of 5 is better than 3 while 3 is better than anything below 3, but I tend to think that both 3 and 5 are bad at low HF bands – say 80 and 40 sure – but lower Kp is fine at 80 and 40m. I have more questions as you progress higher in HF.

I have vague memories of hearing that the aftermath of a geomagnetic storm, as the K index is coming down is a better time to operate on the high end of HF, say 20 to 10m, than once the storm is over. I’m pretty sure I’ve seen that effect on 6m.

An important point to mention is all of these indices vary both on longer and shorter intervals. If you’ve ever watched the NOAA Space Weather Prediction Center’s Planetary K-Index charts, you might have noticed that each bar showing one number for three hours is displayed ending in #.00, #.30 or #60 (where “#” is the whole number below the top of the bar).

That tells me they take a number every hour and the bar they display is an average of three measurements. My mental analogy is measuring the depth of lava in a hole on the side of a volcano. The level goes up and down but is boiling at the same time so there are long and short periods that the level changes over. The number they get is statistically related to the actual levels, but I sure can’t describe how they relate numerically.

Solar Flux (SFI) is the indicator the most people follow, and the more the merrier. The idea that solar flux determines propagation is over simplified because of the effects of the geomagnetic activity and the minute by minute variations in that. The simplest advice is what I heard nearly 50  years ago, when I first got licensed: listen, listen, listen and when you get tired of that, listen some more. There are ways to automate your station, so you don't have to sit there, Butt In Chair, but you can't go wrong with BIC time and listening.