mswx: Monte Sano Weather

mswx is the weather for one place: the Monte Sano plateau above Huntsville, Alabama. It is not a general-purpose weather app. There is no location search, no airport reading, and no generic feed dressed up in a new coat of paint. Everything on screen is measured on the mountain by people who live there, or forecast specifically for it. WHY IT EXISTS Monte Sano sits several hundred feet above the city and has its own microclimate. On calm clear nights it can run ten degrees cooler than downtown; on summer afternoons the difference is what decides whether the pool is worth the walk. Every mainstream weather app fills its "currently" tile from the airport station out by Cummings Research Park, which reads like a different town. Residents got tired of that, so they built their own network. WHAT'S DIFFERENT • Five neighbor-owned personal weather stations on the plateau, combined every minute with a trimmed mean (drop the highest and lowest, average the rest). That is the Monte Sano temperature you see everywhere in the app, and it isn't available from any public weather API. • A matching composite of downtown stations gives a true valley reference, so the app can tell you exactly how much warmer or cooler the mountain is right now, and how tomorrow's highs compare. • Forecasts pull public model output (NWS, Open-Meteo ensemble, Pirate Weather, HRRR) for the plateau's exact coordinates, then apply a bias correction trained on five years of what the mountain actually measured, keyed by hour of day, wind, and sky. The grid systematically underpredicts up here on clear calm nights; the app knows that. • A sensor on the Monte Sano Club pool plumbing reports water temperature every 60 seconds. Combined with the plateau air forecast, that drives a week-out pool water forecast, plus swim and "sit on the bluff" comfort ratings and a sunscreen strip. • Radar nowcast and lightning: whether it is raining on the mountain right now, when it starts or stops, and how close the nearest strike is. • Measured vs. forecast: the Forecast tab overlays what the stations recorded against what was predicted, so you can see how the correction is doing. ALSO • Home Screen and Lock Screen widgets: Conditions (air, pool, or rain first), Pool, Forecast, and Rain. • Apple Watch app with complications for the plateau temperature, pool, and rain. • Free. No account, no sign-in, no location permission, no analytics, no ads. The app talks only to mswx.net. • Full station-by-station detail, every forecast source, and observed history are on the website. WHO IT'S FOR People who live, swim, run, or ride on Monte Sano, and anyone in Huntsville who wants to know what the mountain is doing before they head up. If you are looking for weather somewhere else, this isn't the app; if you are looking for the mountain, nothing else has this data. During severe weather, always follow the National Weather Service, NOAA Weather Radio, and local emergency management.