[metabagel]

I think the most important feature is accuracy. Maybe, Apple Weather is more accurate for other regions, but by my observation it is absolutely not accurate in regards to predicting rain where I live in Southern California. And we don’t even get that much rain.

[mh-]

It's completely inaccurate with regards to "is it raining right now" in San Diego County. Given that, it's predictions are beyond useless.

I didn't live here when Dark Sky was still good, but Dark Sky was incredibly accurate when I lived in the Bay Area.

[counters]

> I didn't live here when Dark Sky was still good, but Dark Sky was incredibly accurate when I lived in the Bay Area.

I'm kind of skeptical about that, given that the Bay Area has relatively poor radar coverage. The local NEXRAD site is near Mt Umunhum south of San Jose and is quite elevated, so the lowest scanning tilt has limited coverage below ~4,000 feet over much of the SF peninsula and into the Golden Gate. The consequence is that shallow maritime convection can be poorly observed by the radar, and you can frequently have low cloud decks that produce noticeable drizzle or light rain (although possibly not greatly accumulating) across the city and surrounding area wihtout seeing anything on radar. Since Dark Sky wasn't much more than re-packaged NEXRAD data, it has a GIGO problem - if the radars don't see rain, Dark Sky won't predict anything for you.

The exception are the large storm systems that come ashore a few times per year in the Winter and Spring. Those systems behave extremely linearly, so they were "easy" for the algorithms that Dark Sky used to process the radar data. That ease of analysis combined with infrequency probably skews the perception that Dark Sky performed well in the Bay Area.

For what it's worth, I was involved in a study that analyzed the performance of several consumer and enterprise products' performance for reporting and forecasting light rain specifically in the Bay Area, and Dark Sky was indistinguishable from other data products that very obviously used raw, unprocessed NEXRAD data.

[mh-]

That's great context, thank you.

I think my only response is that my bar for "incredibly accurate" has gotten very, very low, given the performance here where I'm living now.

I obviously haven't done any kind of quantitative analysis, but I wouldn't be surprised to find it's genuinely worse than a coin toss.

Oh, I should add that I was living in East Bay closer to Walnut Creek for much of my time there. If I understand your point about the radar coverage correctly, I expect the Oakland hills topology would interact with that limitation somehow?

[counters]

I'm pretty sure KMUX is fully unobstructed (no beam blockage) at the lowest scan elevation, but I don't have a graphic or source at my fingertips to confirm that. I don't recall any difference in quality between East Bay and interior up through Walnut Creek and the SF / Golden Gate peninsulas.