Météo-France AROME Rainfall Forecast

About this data

• Météo-France AROME forecast: Météo-France AROME France HD (about 1 km), Open Licence 2.0 (Etalab), via Open-Meteo (open-meteo.com) Open Data
• Model runs: Eight runs a day, every three hours from 00 GMT, each becoming available about four hours after its nominal time and reaching T+51 hours in hourly steps. AROME is the Météo-France model run on a grid of about 1km, fine enough to resolve showers and the effect of hills. Its area stops near 55.4N, so it covers Ireland, Wales and England up to the Scottish border but not Scotland. Areas that are not wholly inside it have no value, and the map says so rather than showing a partial figure. It publishes no pressure field, so there are no isobars.
• Trial pipeline: this feed is built by a second, newer data pipeline (a small always-on server rather than the site's usual scheduled jobs), run alongside the existing one to see how well it holds up. The freshness dot above shows how old its newest data is.
• Deterministic, not a probability: this is a single model solution, so it shows one possible outcome rather than a range. Treat it as guidance on pattern and timing, not as a forecast of exact totals at a place.
• Comparing models: all seven render to the same map extent with the same colour scale, so a colour means the same millimetres whichever is selected. Differences you see between them are the models disagreeing, not the maps being drawn differently.
• Isobars (MSLP): on by default, drawn as pressure lines over the rainfall; switch them off behind the settings button on the controls bar (or on the bar itself, on a wide enough screen). H/L pressure centres are labelled with their central pressure in hPa.
• Catchment boundaries: National River Flow Archive (2014). NERC Environmental Information Data Centre. doi:10.5285/1957166d.
• Region / county boundaries: Office for National Statistics (ONS), Open Government Licence v3.0. Contains OS data © Crown copyright and database right.
• Temperature anomaly: the model's 2 m temperature (from its temperature picture) less the normal for that date and hour, both averaged over cells of about 0.7 degrees, so it shows the pattern rather than exact values. The normal is ERA5 hourly climatology for 1990 to 2019 (contains modified Copernicus Climate Change Service information, via WeatherBench2), set over the UK to the Met Office HadUK-Grid 1991 to 2020 long-term monthly mean temperature (contains Met Office data © Crown copyright, Open Government Licence v3.0, via the CEDA Archive).
• Basemap: © OpenStreetMap contributors © CARTO.