UK Met Office - C-band rain radar composite

This notebook describes how to access and use the zarr-version of the UK Met Office C-band rain radar 1 km composite dataset. The dataset provides 5-minute precipitation rates in mm/h at 1 km × 1 km spatial resolution over the United Kingdom, derived from the Met Office radar network. The data uses the OSGB 1936 / British National Grid projection (EPSG:27700). The v0.1.0 zarr version of the dataset covers July 2005 to the end of 2025.

The raw NIMROD data was downloaded from CEDA and converted using mlcast-dataset-metoffice-nimrod and mlcast-dataset-tiff2zarr.

import matplotlib.pyplot as plt
import cartopy.crs as ccrs

import mlcast_datasets

cat = mlcast_datasets.open_catalog()
list(cat.precipitation)

['radklim_hourly',
 'radklim_5_minutes',
 'dmi_10_minutes',
 'it_dpc_sri_5min',
 'uk_metoffice_5min',
 'be_rmi_radclim_mfb_5min']

UK Met Office 5-min radar precipitation¶

The UK Met Office radar dataset is available in the intake catalog as uk_metoffice_5min.

ds = cat.precipitation.uk_metoffice_5min.to_dask()
ds

var_name = "RR"

crs_name = ds[var_name].grid_mapping
data_crs = ccrs.Projection(ds[crs_name].crs_wkt)

g = (
    ds[var_name]
    .sel(time="2020-10-03T12")
    .isel(time=slice(None, 3))
    .plot(
        transform=data_crs,
        cmap="viridis",
        add_colorbar=True,
        col="time",
        robust=True,
        subplot_kws=dict(projection=data_crs),
        vmin=0,
    )
)

for ax in g.axs.flat:
    ax.coastlines()
    ax.gridlines(draw_labels=["top", "left"])

/home/runner/work/mlcast-datasets/mlcast-datasets/.venv/lib/python3.12/site-packages/cartopy/io/__init__.py:242: DownloadWarning: Downloading: https://naturalearth.s3.amazonaws.com/50m_physical/ne_50m_coastline.zip
  warnings.warn(f'Downloading: {url}', DownloadWarning)