This repository contains the data used in the manuscript "Cell tracking -based framework for assessing nowcasting model skill in reproducing growth and decay of convective rainfall" by Ritvanen, J., Pulkkinen, S., Moisseev, D., and Nerini, D. submitted to the Geoscientific Model Development journal.

A description of the data files is provided below.

observations.zip

The observation data is provided as a single hdf5 file swiss_composite_bbox_26012024.h5, with the structure

txt ├YYYY-mm-dd HH:MM:SS │ └measurements │ ├data [uint8: 640 × 704] │ │ └2 attributes: │ │ ├CLASS: b'IMAGE' │ │ └IMAGE_VERSION: b'1.2' │ └what │ └1 attributes: │ ├quantity: 'RATE' │ ├units: 'mm/h'

The values are packed using a lookup table, which is provided in the metranet_lookup.py file, where the variable METRANET_RR_8BIT contains the rain rate values in units of mm/h corresponding to the packed values from 0 to 255.

The data is saved in a metric coordinate system with the following projection string: +proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=2600000 +y_0=1200000 +ellps=bessel +towgs84=674.374,15.056,405.346,0,0,0,0 +units=m +no_defs

The corner coordinates of the data are:

"UR_lon": 12.463400010413896, "UR_lat": 49.36540000898943, "LL_lon": 3.2432298672374404, "LL_lat": 43.63301754190871,

nowcasts.zip

The zip file contains the nowcast data used in the study.

NOTE: the uncompressed size of the files is approximately 53GB.

The following files contain the nowcast data:

• extrapolation_swiss_composite_bbox_26012024.h5: the advection nowcast
• lcnn_diff_rmse_swiss_31012024.h5: the L-CNN nowcast
• linda_domain_swiss_composite_bbox_26012024.h5: the LINDA nowcast
• sprog_swiss_composite_bbox_26012024.h5: the S-PROG nowcast

The files have the following structure:

```txt ├YYYY-mm-dd HH:MM:SS

├ │ ├data [uint8: 640 × 704] │ │ └2 attributes: │ │ ├CLASS: b'IMAGE' │ │ └IMAGE_VERSION: b'1.2' │ └what │ └13 attributes: │ ├LL_lat: 43.63301754190871 │ ├LL_lon: 3.2432298672374404 │ ├UR_lat: 49.36540000898943 │ ├UR_lon: 12.463400010413896 │ ├description: │ ├institution: 'MeteoSwiss' │ ├lookup: 'METRANET_RR_8BIT' │ ├projdef: '`+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=2600000 +y_0=1200000 +ellps=bessel +towgs84=674.374,15.056,405.346,0,0,0,0 +units=m +no_defs' │ ├qty: 'RATE' │ ├timestep: 5 │ ├unit: 'mm/h' │ ├xsize: 704 │ └ysize: 640 ├ │ ├data [uint8: 640 × 704] │ │ └2 attributes: │ │ ├CLASS: b'IMAGE' │ │ └IMAGE_VERSION: b'1.2' │ └what │ └13 attributes: ...

```

where is the name of the nowcasting model and is the index of the lead time of the nowcast starting from 1 (e.g. 1=5min, 2=10min, 3=15min, ...). The model names are:

• extrapolation: the advection nowcast
• linda: the LINDA nowcast
• sprog: the S-PROG nowcast
• lcnn-diff-rmse-31012024: the L-CNN nowcast

The values are packed using a lookup table, which is provided in the metranet_lookup.py file, where the variable METRANET_RR_8BIT contains the rain rate values in units of mm/h corresponding to the packed values from 0 to 255.

The data is saved in a metric coordinate system with the following projection string: +proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=2600000 +y_0=1200000 +ellps=bessel +towgs84=674.374,15.056,405.346,0,0,0,0 +units=m +no_defs

The corner coordinates of the data are:

"UR_lon": 12.463400010413896, "UR_lat": 49.36540000898943, "LL_lon": 3.2432298672374404, "LL_lat": 43.63301754190871