I apologize in advance because it won’t last long, but if I describe it, maybe someone who comes along after it’s fixed will still know.
Here’s the link:
What it looks like is that there is a radar site in Montana with a radius that extends into Idaho. In a circle all around are blue lines that would appear to be snowfall, but obviously aren’t because snowstorms don’t usually form in perfect circles the size of Western states.
What’s going on?
Sorry, but the image on that link has already changed.
Around here, it’s common for a radar site to have multiple types of radar. Longer range radars are easier for local (to the antenna) inclement weather to block/knock out
Alternatively, extreme weather could simply decrease the effective range of a given radar, so instead of seeing broad overlapping fields of coverage, you could see smaller circles of effective range, with less or no overlap, each circle displaying heavy inclement weather.
It’s like driving in a fog. Just because you can’t see past 100 feet doesn’t mean there’s no fog at 101 feet. There probably is. Your eyes just have no data to report
Absence of evidence is not evidence of absence.
(just a thoufht for your consideration, since the link no longer shows whatever you saw. It may not apply if the regional weather is not inclement.)
I’ve noticed something similar on accuweather in my area, except the circular “dropout” is much smaller and either a) in the most active region of, say, a nearby heavy snowstorm, or b) immediately surrounding the local radars (as a private pilot, I recognized them as the locations of the largest local airports, including the very local Air Force Base runway I usually flew out of), over the years, I’ve concluded that the extremely high “return” from very heavy, very local weather creates an overload, unreliably noisy signals, or otherwise uninterpretable data that is rejected by the local radar computer and/or shared network