MOSMIX Weather Pipeline

A self-hosted PHP pipeline that downloads DWD MOSMIX-L weather forecast data, stores it in a local SQLite database, and serves it via a JSON API with an interactive web frontend.

Features

• Downloads and parses the full DWD MOSMIX-L KMZ file (~200 MB, ~5,000+ stations worldwide) every 6 hours
• Streams the KML using XMLReader + SimpleXML for low memory usage (~1 GB limit sufficient)
• Spatial interpolation (IDW – Inverse Distance Weighting) with elevation correction for arbitrary coordinates
• Pre-computed forecasts for fixed locations defined in locations.txt
• City search with autocomplete (GeoNames DE/AT/CH, ~100k places)
• JSON API for on-demand forecasts and saved locations
• Interactive frontend with temperature/precipitation/wind charts (Chart.js) and two animated radar panels (RainViewer + DWD WMS)
• Radar panels are zoom-synchronized; animation speed is adjustable via slider

Requirements

• PHP 8.1+ (tested on 8.3) with extensions: sqlite3, curl, zip, xml (SimpleXMLElement + XMLReader)
• A web server (Apache, Nginx) with PHP-FPM or mod_php
• ~500 MB free disk space for the database and KMZ cache

Install PHP extensions (Debian/Ubuntu)

sudo apt install php8.3-sqlite3 php8.3-curl php8.3-zip php8.3-xml

Installation

git clone https://github.com/YOUR_USERNAME/mosmix.git /var/www/html/mosmix
cd /var/www/html/mosmix

The web root must be served by your web server. No Composer dependencies — all JS/CSS assets are included under assets/.

First run

1. Import the cities database (one-time)

This populates the cities table used for location search and locations.txt name resolution:

php import_cities.php

Takes ~2–5 minutes (queries Wikidata SPARQL for DE, AT, CH cities with population ≥ 5,000).

2. Define your locations

Edit locations.txt — one location per line:

# City name (resolved via cities DB)
Berlin
München

# Coordinates: lat,lon  or  lat,lon,elevation_m
48.137,11.576,519
54.75,9.5,33

Lines starting with # and blank lines are ignored.

3. Run the pipeline

php pipeline.php

This downloads the MOSMIX-L KMZ (~200 MB), parses all stations, and interpolates forecasts for your locations. Takes about 5–15 minutes depending on hardware.

Cron job

Run every 6 hours, offset by 30 minutes to account for DWD upload lag:

30 0,6,12,18 * * * /usr/bin/php /var/www/html/mosmix/pipeline.php >> /var/log/mosmix.log 2>&1

Recompute locations only (no download)

If you change locations.txt and don't want to re-download the KMZ:

php pipeline.php locations

File structure

mosmix/
├── pipeline.php        # Download, parse, interpolate – the main cron script
├── api.php             # JSON API (search, forecast, locations, precomputed, meta)
├── lib.php             # Shared library: IDW, WW codes, DB helpers
├── import_cities.php   # One-time city import from Wikidata (DE/AT/CH)
├── index.php           # Web frontend (charts + radar panels)
├── locations.txt       # Your saved locations (edit this)
├── mosmix.sqlite3      # SQLite database (created on first run, not in repo)
├── data/
│   └── MOSMIX_L_LATEST.kmz   # Downloaded KMZ cache (not in repo)
└── assets/
    ├── chart.umd.min.js       # Chart.js (local)
    ├── leaflet.js             # Leaflet 1.9.4 (local)
    ├── leaflet.css
    └── images/                # Leaflet marker icons

Database schema

Table	Purpose
stations	All DWD MOSMIX stations (id, name, lat, lon, elevation)
forecasts	Raw per-station forecast data (hourly, ~240 h horizon)
my_locations	Your saved locations from locations.txt
my_forecasts	Pre-interpolated forecasts for saved locations
cities	GeoNames city data for search (populated by import_cities.php)
meta	Pipeline run metadata (import time, model run, data range)

API endpoints

All endpoints are GET requests to api.php.

Action	Parameters	Description
search	q (string, min 2 chars), limit (int, default 10)	City autocomplete
forecast	lat, lon, elev (optional), hours (default 12, max 240)	On-demand IDW interpolation
precomputed	id (location id), hours (default 12, max 240)	Pre-computed forecast for saved location
locations	—	List all saved locations
meta	—	Database and pipeline metadata

Example:

curl "http://localhost/mosmix/api.php?action=forecast&lat=48.137&lon=11.576&elev=519&hours=48"

Configuration

Constants in pipeline.php and lib.php (defaults shown):

Constant	Default	Description
SEARCH_RADIUS_DEG	1.0	Station search radius in degrees (~111 km)
IDW_NEIGHBORS	4	Number of nearest stations for interpolation
ELEV_PENALTY_KM	0.1	km penalty per 100 m elevation difference
RAIN_ACCUM_HOURS	6	Rolling rain accumulation window
TZ_LOCAL	Europe/Berlin	Local timezone for time block alignment

.gitignore

Add the following to avoid committing the database and downloaded data:

mosmix.sqlite3
mosmix.db
data/MOSMIX_L_LATEST.kmz
data/MOSMIX_L_LATEST_240.kmz
locations.txt~

Data sources

• DWD MOSMIX-L: opendata.dwd.de — Open Data, DWD licence
• Radar (RainViewer): rainviewer.com API
• Radar (DWD WMS): maps.dwd.de — layer dwd:Niederschlagsradar
• Cities (Wikidata): CC0 — queried once during setup via import_cities.php

Licence

MIT