Neginato
10-model NWP ensemble
Synthesizes NOAA NWS Grid, NOAA HRRR, NOAA NBM, ECMWF IFS, NOAA GFS, DWD ICON, ECCC GEM, UK Met Office, Météo-France, and MET Norway across four US lead-time horizon bands (H0: 0–3h to H3: 72h+) and worldwide.
Native macOS · 10-Model Ensemble · Open Source GPL v3
Every forecast, blended from the source.
Neginato Mezora is a native Swift 6 / SwiftUI meteorological workstation and precipitation nowcasting app for macOS. It blends up to 10 numerical weather prediction (NWP) models across three free, unauthenticated providers, fuses them with live physical airport METAR observations and US EPA AirNow monitors, and plots unambiguous sub-hourly rain rate and probability charts.
Free & Open Source (GPL-3.0-or-later) · Signed & notarized · Requires macOS 27 or later
10 NWP models
15-min HRRR nowcast
3D METAR assimilation
Configurable blend weights
No API keys or GPS
What makes it different
Multi-model physics, not a single black-box feed.
Instead of trusting one weather vendor, Neginato Mezora queries three free upstream providers directly from your Mac and computes an IEEE-754 weighted median across up to 10 global and high-resolution regional models.
Self-documenting rain charts
Side-by-side Next 2 hours (15-minute HRRR nowcast) and Next 24 hours charts plot expected rain rate as cyan bars against the left axis and rain probability as a smooth monotone cubic Hermite curve against the right axis — with peak callout badges and interactive hover readouts.
3D live station assimilation
Assimilates up to 16 nearby NOAA/FAA AviationWeather METAR airport stations within 95 km using a 3D anisotropic Cauchy-Gaussian spatial kernel, 90m DEM diurnal lapse-rate reduction, Shepard (1968) directional de-clustering, MAD outlier QC, and 6-hour MOS exponential bias decay.
Tunable sources & weights (⌘,)
Open the native macOS Settings window to enable or disable Open-Meteo, National Weather Service, and MET Norway, inspect live per-place model counts, and adjust source multipliers (0.10×–3.00×) or individual model weights (0.00×–3.00×).
EPA AirNow & psychrometrics
Displays real-time US EPA AirNow Air Quality Index (AQI), primary pollutant (PM2.5, O3, PM10), and 24-hour AQI delta alongside Stull (2011) wet-bulb temperature, Magnus-Tetens dew point, Rothfusz Heat Index, Wind Chill, and radiative cloud cover.
Street addresses & interactive pins
Press ⌘N to search any street address, postal code, city, or raw lat, lon coordinates across 5 geocoders, or drop a pin on the interactive Apple Map and give any place a custom name like Home or Studio.
Honest 48-hour rain timing
Plain-language summaries like “Raining now, easing around 7 PM” or “No rain expected for the next 48 hours.” Mezora only claims “Dry” when the entire 48-hour horizon is covered with zero data gaps.
Open source & documented math
Licensed under GPL-3.0-or-later, with a bundled searchable macOS Help Book (⌘?) and full mathematical derivations and academic citations in the repository.
Two questions answered at a glance: how hard, and how likely. Most weather apps mix precipitation amount and probability into a single unmarked bar. Neginato Mezora separates them explicitly: cyan-blue vertical bars plot expected rain rate (in/h or mm/h) against the left Y-axis, while the amber-rose monotone cubic curve plots precipitation probability (0%–100%) against the right Y-axis. Hover any time slot to inspect the exact rate and chance side by side.
For US CONUS locations, 15-minute NOAA HRRR sub-hourly nowcasts are rescaled mass-conservatively against the blended hourly total so sub-hourly intensity spikes are preserved without distorting synoptic accumulation.
Requires macOS 27 or later
Open-Meteo · NOAA NWS · MET Norway · EPA AirNow
Open Source (GPL-3.0-or-later)
Available now
See the forecast behind the forecast.
Download Neginato Mezora for macOS — free, signed & notarized, and open source under GPL v3. No accounts, no API keys, and no location tracking.
Free & Open Source (GPL v3) · Signed & notarized · Requires macOS 27 or later