# Description:
Dataset of forecasted freezing level height from the numerical weather prediction model HARMONIE-AROME cycle 38, as of 3 April 2018 cycle 40. HARMONIE-AROME is a non-hydrostatic regional numerical weather prediction model used operationally at the Royal Netherlands Meteorological Institute (KNMI) and various other European weather centers. At KNMI, the HARMONIE-AROME model operates at 2.5 times 2.5 km horizontal resolution and 65 vertical levels, and 48-hour long forecasts are initiated every three hours. A subset of the full output was archived on model-levels for a 300 times 300 cell domain covering part of the full 800 times 800 cell simulation domain. For each cell and simulation output time-step, the freezing level height was determined by scanning from the top of the atmosphere downwards to the first level for which the temperature reached 273.15K. The subset covers the Netherlands and surroundings, coinciding with the coverage of the two KNMI ground-based weather radars. This dataset has been employed for a study on rainfall-induced attenuation correction for two dual-pol C-band radars in the Netherlands, for which a paper is in preparation. For this, HARMONIE data which would have been available in real-time for coupling with real-time 5-min radar data were obtained, resulting in the selection of the forecasts with +2, +3, +4 or +5 h lead time, being available every 3 h (32 files per day). The HARMONIE data allow for distinguishing between rain and other types of precipitation. This dataset may also be useful for other (radar) applications. Details on HARMONIE-AROME can be found in Bengtsson, L., and Coauthors, 2017: The HARMONIE-AROME model configuration in the ALADIN-HIRLAM NWP system. Mon. Wea. Rev., 145, 1919-1935, doi:10.1175/MWR-D-16-0417.1.


# Data files:
One folder with 10844 netCDF4 files. Each file contains the freezing level height for one model run and one lead time. The file name contains the date and time in UTC. E.g. "HA38_N25_201708132100_00200_GB_selheight_reduced.nc" contains the freezing level height from the model run from 13 August 2017 2100 UTC for the +2 h lead time. Data from the period 31 July 2017 up to and including 31 July 2018, and data from 18, 19 and 20 June 2019 are provided. The file name changes from "HA38..." to "HA40..." as of 3 April 2018. Due to storage issues, data are available for 345 out of 369 days. The average data availability over the 369-day period is 91.8%. 


# Explanation of data fields:

lat 
Latitude of middle of grid cell (degrees North).

lfreezetip 
Freezing level (m above mean sea level). A NaN value indicates a height below mean sea level.

lon
Longitude of middle of grid cell (degrees East).