FAQ

BUFKIT is the forecast profile format the National Weather Service uses for model soundings. Each file holds a vertical profile of the atmosphere for one station, for every forecast hour of one model run. Sondex downloads these files from the Iowa Environmental Mesonet and draws them.

GFS, HRRR, RAP and RRFS, across a catalog of 1,078 stations in the US, Alaska, Hawaii and the territories. Not every model covers every station; Sondex lists what each station carries and the newest cycle of each.

NAM and NAM 4 km were retired on Nov 3 2026, when RRFS replaced them. Their last runs are that day's 06Z cycle. A station that followed either one now follows RRFS, which covers 1,024 of the 1,078 stations. NAM runs you downloaded stay on your device, and a station's historical runs still reach NAM through Nov 3.

$5, once, on the App Store at launch. Every feature is included, with no subscription. The optional Supporter Pack is a one-time tip that adds cosmetic options, such as the Print and Monochrome chart themes. During the TestFlight beta the app is free.

It's written on your device. Where Apple Intelligence is available, Apple's on-device model narrates a digest of the file; everywhere else, rule-based templates write it. The read only quotes numbers that are in the sounding, and it never leaves your device.

Monitor a station and Sondex pulls each new cycle of the models you follow as the Iowa Environmental Mesonet posts it, using background refresh on iPhone and iPad. HRRR and GFS are on by default; add RAP and RRFS per station. Set an end date and monitoring stops on its own, with Monitor Again one tap away.

One sentence that reads every monitored station's newest runs for the next 48 hours, the SPC Day 1 and Day 2 outlooks on a map with your stations on it, and a ribbon per station of each model's storm chance by hour. Tap an hour and the Skew-T opens on it.

Yes. Choose files, paste a link or the file itself, use Open in Sondex, or drop files on the window on Mac. Every import ends on a review sheet that lists what was added or replaced, including each run inside a .buz archive.

Yes. Downloaded runs stay on your device, so every chart, the readouts and the forecast read work without a connection. That makes it useful in the field.

iPhone and iPad with iOS 26 or iPadOS 26 or later, and Mac with macOS 26 or later. On iPhone Duo the layout follows the fold: the chart keeps its full height on the outer display with the scrubber in the side bar, and two-pane screens put their seam on the hinge.